Rapid Characterization of Undeclared Pharmaceuticals in Herbal Preparations by Ambient Ionization Mass Spectrometry for Emergency Care

In Asia, some herbal preparations have been found to be adulterated with undeclared synthetic medicines to increase their therapeutic efficiency. Many of these adulterants were found to be toxic when overdosed and have been documented to bring about severe, even life-threatening acute poisoning events. The objective of this study is to develop a rapid and sensitive ambient ionization mass spectrometric platform to characterize the undeclared toxic adulterated ingredients in herbal preparations. Several common adulterants were spiked into different herbal preparations and human sera to simulate the clinical conditions of acute poisoning. They were then sampled with a metallic probe and analyzed by the thermal desorption-electrospray ionization mass spectrometry. The experimental parameters including sensitivity, specificity, accuracy, and turnaround time were prudently optimized in this study. Since tedious and time-consuming pretreatment of the sample is unnecessary, the toxic adulterants could be characterized within 60 s. The results can help emergency physicians to make clinical judgments and prescribe appropriate antidotes or supportive treatment in a time-sensitive manner.

Rapid identification of mushroom toxins by direct electrospray probe mass spectrometry for emergency care

Mushroom poisoning occurs frequently after the ingestion of toxic wild mushrooms misidentified as edible species. The goal of this study is to develop a mass spectrometric platform to bypass the need for morphological recognition of poisonous mushrooms by experts and rapidly identify the toxins in the mushrooms for emergency care. Trace mushroom toxins were collected by penetrating and removing the mushrooms surface for 3 mm with a direct electrospray probe (DEP). The analytes on the DEP were then dissolved in the solution (70% isopropanol containing 0.1% acetic acid) flowing out of a solvent reservoir on the DEP. Electrospray ionization was induced from the sample solution as a high electric field was generated between the DEP and MS inlet. The obtaining mass spectrometric results were further analyzed with principal component analysis (PCA) to classify mushroom toxins. The mass spectrometric platform for detecting mushroom toxins was assessed for its sensitivity, precision, and efficiency by determining its limit-of-detection (LOD), repeatability, and turnaround time, respectively. As a result, the LODs of the mushroom toxins in pure methanol and spiked in human vomitus by DEP/MS were within 0.001-0.5 ng/μL and 0.01-1 ng/μL, respectively. Linear responses of the mushroom toxins in pure methanol with concentrations between 0.01 and 5 ng/μL (R2 between 0.9922 and 0.998) were obtained. The repeatability of the approach (n = 10) was shown in the low relative standard deviation value (<15%) from ten repeat analysis of mushroom toxins standard solution. The corresponding toxic compounds were identified through matching of the obtained mass spectrometric data with those provided by its companion database library of mushroom toxins. Since no time-consuming pretreatment of the samples is required, identification of mushroom toxins with DEP/MS was complete within 1 min. This will be helpful for the emergency physicians to make correct clinical judgment and prescribe appropriate medical treatment in a timely manner.

High throughput analysis of alendronate in human samples with derivatization-free hydrophilic-interactive chromatography mass spectrometry

A derivatization-free hydrophilic-interactive chromatography-mass spectrometry (HILIC-MS/MS) method was developed for quantifying low levels of alendronate in human plasma. Alendronate was separated and concentrated using calcium co-precipitation and analyzed by HILIC-MS/MS, requiring only a 300 μL plasma sample for each analysis. The method is simpler, safer, and more environmentally friendly than the conventional LC-MS/MS method that requires solid-phase extraction and derivatization steps during sample pretreatment. The method was validated for selectivity, linearity, precision, accuracy, extraction recovery, matrix effect and limit of quantification. The between-run precisions were no more than 7.1 % with accuracy ranging from - 1.7-6.3 %; extraction recovery was determined to be 85.3 %; while validation results indicated that the method was suitable for accurately quantifying alendronate concentrations in the range from 0.2 to 50 ng/mL. The approach was used successfully for high throughput analysis of alendronate in more than 3700 plasma samples from 120 subjects in a bioequivalence study.

Facile analysis of mycotoxin in coffee and tea samples using a novel semi-automated in-syringe based fast mycotoxin extraction (FaMEx) technique coupled with direct-injection ESI-MS/MS analysis

Identifying the risk of ochratoxin A in our daily food has become fundamental because of its toxicity. In this work, we report a novel semi-automated in-syringe-based fast mycotoxin extraction (IS-FaMEx) technique coupled with direct-injection electrospray-ionization tandem mass spectrometer (ESI-MS/MS) detection for the quantification of ochratoxin A in coffee and tea samples. Under the optimized conditions, the results reveal that the developed method's linearity was more remarkable, with a correlation coefficient of > 0.999 and > 92% extraction recovery with a precision of 6%. The detection and quantification limits for ochratoxin A were 0.2 and 0.8 ng g-1 for the developed method, respectively, which is lower than the European Union regulatory limit of toxicity for ochratoxin-A (5 ng g-1) in coffee. Furthermore, the newly developed modified IS-FaMEx-ESI-MS/MS exhibited lower signal suppression of 8% with a good green metric score of 0.64. In addition, the IS-FaMEx-ESI-MS/MS showed good extraction recovery, matrix elimination, good detection, and quantification limits with high accuracy and precision due to the fewer extraction steps with semi-automation. Therefore, the presented method can be applied as a potential methodology for the detection of mycotoxins in food products for food safety and quality control purposes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05733-z.

Ultra-sensitive determination of Ochratoxin A in coffee and tea samples using a novel semi-automated in-syringe based coagulant-assisted fast mycotoxin extraction (FaMEx) technique coupled with UHPLC-MS/MS

In this study, we demonstrated a novel semi-automated in-syringe-based coagulant-assisted liquid-liquid microextraction (IS-CGA-LLME) as fast mycotoxin extraction (FaMEx) technique coupled with ultra-high-performance liquid chromatography connected with a tandem-mass spectrometer (UHPLC-MS/MS) for the quantification of mycotoxin (Ochratoxin A, OT-A) in coffee and tea samples. IS-CGA-LLME is a three-step extraction process that includes extraction of OT-A from sample matrix using low-volume solvent extraction, then the extractant was cleaned-up using a coagulation process, and finally, the decolorized/matrix removed sample solution was processed for LLME for target analyte's pre-concentration. The final extractant was analyzed using UHPLC-MS/MS for OT-A quantification. Under the optimized experimental conditions, highly sensitive detection and quantification limits were obtained at 0.001 and 0.003 ng g^-1 for OT-A with excellent extraction recovery (93-111%) and precision <10%. These results proved that the developed method is a simple, highly sensitive, semi-automated, low-matrix effect and efficient procedure for the determination of mycotoxins in food samples.

A low-cost eco-friendly fast drug extraction (FaDEx) technique for environmental and bio-monitoring of psychoactive drug in urban water and sports-persons' urine samples

Nicotine is the most prominent psychoactive/addictive chemical substance consumed worldwide among young players in team sports. Moreover, urinary nicotine discharge and nicotine-based products disposal in environmental waters has been unavoidable in recent years. Therefore, sensitive monitoring of nicotine content in environmental waters and human urine samples is essential. In this study, we developed a miniaturized novel green, low-cost, sensitive, in-syringe-based semi-automated fast drug extraction (FaDEx) protocol coupled with gas chromatography-flame ionization detection (GC-FID) for the efficient environmental and bio-monitoring of nicotine in aqueous samples. The FaDEx method consists of two steps; firstly, the target analyte was extracted using dimethyl carbonate (a green solvent) and extraction salts. After that, the extraction solvent was passed automatically through the solid-phase extraction cartridge at a constant flow rate for the cleanup process to achieve the sensitive nicotine analysis by GC-FID. Under optimized experimental conditions, the developed method showed excellent linearity over the concentration ranges between 20-2000 ng mL^-1 with a correlation coefficient >0.99. The detection and quantification limits were 4 and 20 ng mL^-1, respectively. The presented method was applied to monitor and assess nicotine exposure in sports-persons' urine and environmental water samples. The method accuracy and precision in terms of relative recovery and relative standard deviation (for triplicate analysis) were 85.4-110.2% and ≤8%, respectively. Finally, the impact of our procedure on the environment from a green analytical chemistry view was assessed using a novel metric system called AGREE, and obtained the greenness score of 0.87, indicating its an efficient alternative green analytical protocol for routine environmental and bio-monitoring of nicotine in environmental and biological samples.

Novel fast pesticides extraction (FaPEx) strategy coupled with UHPLC-MS/MS for rapid monitoring of emerging pollutant fipronil and its metabolite in food and environmental samples

In this work, we demonstrated a new, environmental-friendly and effective sample preparation strategy named 'in-syringe-assisted fast pesticides extraction (FaPEx)' technique coupled with LC-MS/MS for the rapid identification and monitoring of emerging pollutant fipronil and its metabolite fipronil sulfone in chicken egg and environmental soil samples. FaPEx strategy comprising of two simple steps. Firstly, the sample was placed in the syringe and extracted using low-volume acetonitrile with NaCl and anhydrous MgSO₄ salts. Secondly, the extractant was passed through in-syringe-based solid-phase extraction (SPE) kit containing cleanup sorbents and salt combinations (C18, primary secondary amine, and anhydrous MgSO₄) for the cleanup process. Then, the obtained clean extractant was injected into LC-MS/MS for the quantification of target analytes. Various important parameters influencing the FaPEx performances, such as solvent type, salt type, salt amount, sorbent type, and amount, were examined and optimized. The method validation results showed excellent linearity with high correlation coefficients were ≥ 0.99. The estimated LODs were between 0.05-0.07 μg/kg, and LOQs ranged between 0.1-0.25 μg/kg for target analytes in both egg and soil sample matrices, and precision values were ≤7.90%. The developed method was applied to commercial chicken egg samples and environmental soil samples analysis. Spiked recoveries ranged between 88.75-110.91% for egg samples with RSDs ≤7.42% and 82.47-107.46% for soil samples with RSDs <7.37%. These results proved that the developed sample preparation method is a simple, fast, green, low-cost, and efficient method for the analysis of fipronil and its metabolites in food and environmental samples. Thus, this method can be applied as an alternative analytical methodology in routine and standard food and environmental testing laboratories.

Thin layer chromatography/desorption flame-induced atmospheric pressure chemical ionization/mass spectrometry for the analysis of volatile and semi-volatile mixtures

Flame-induced atmospheric pressure chemical ionization (FAPCI) has been used to directly characterize chemical compounds on a glass rod and drug tablet surfaces. In this study, FAPCI was further applied to interface thin layer chromatography (TLC) and mass spectrometry (MS) for mixture analysis.

METHODS

A micro-sized oxyacetylene flame was generated using a small concentric tube system. Hot gas flow and primary reactive species from the micro-flame were directed toward a developed TLC gel plate to thermally desorb and ionize analytes on the gel surface. The resulting analyte ions subsequently entered the MS inlet for detection.

RESULTS

A 1-1.5-mm-wide light-brown line was observed on the TLC plate after the desorption FAPCI/MS (DFAPCI/MS) analysis, revealing that the gel surface withstood a high temperature from the impact of the micro-flame. Volatile and semi-volatile chemical compounds, including amine and amide standards, drugs, and aromatherapy oils, were successfully desorbed, ionized, and detected using this TLC/DFAPCI/MS. The limit of detection of TLC-DFAPCI/MS was determined to be 5 ng/spot for dibenzylamine and ethenzamide.

CONCLUSIONS

TLC/DFAPCI/MS is one of the simplest TLC-MS interfaces showing the advantages such as low costs and an easy set up. The technique is useful for characterizing thermally stable volatile and semi-volatile compounds in a mixture.

Thermogravimetry combined with electrospray and atmospheric pressure chemical ionization mass spectrometry for characterization of synthetic polymers

RATIONALE

Thermogravimetry (TG) combined with electrospray and atmospheric chemical ionization (ESI+APCI) mass spectrometry (MS) was developed to rapidly characterize thermal decomposition products of synthetic polymers and plastic products. The ESI-based TG-MS method is useful for characterizing thermally labile, nonvolatile, and polar compounds over an extensive mass range; and the APCI-based TG-MS counterpart is useful for characterizing volatile and nonpolar compounds. Both polar and nonpolar compounds can be simultaneously detected by ESI+APCI-based TG-MS.

METHODS

Analytes with different volatility were produced from TG operated at different temperatures, which were delivered through a heated stainless-steel tube to the ESI+APCI source where they reacted with the primary charged species generated from electrospray and atmospheric pressure chemical ionization (ESI+APCI) of solvent and nitrogen. The analyte ions were then detected by an ion trap mass spectrometer.

RESULTS

A semi-volatile PEG 600 standard was used as the sample and protonated and sodiated molecular ions together with adduct ions including [(PEG)n + 15]⁺ , [(PEG)n + 18]⁺ , and [(PEG)n + 29]⁺ were detected by TG-ESI+APCI-MS. The technique was further utilized to characterize thermal decomposition products of nonvolatile polypropylene glycol (PPG) and polystyrene (PS) standards, as well as a PS-made water cup and coffee cup lid. The characteristic fragments of PPG and PS with mass differences of 58 and 104 between respective ion peaks were detected at the maximum decomposition temperature (T_max ).

CONCLUSIONS

The information obtained from the TG-ESI+APCI-MS analysis is useful in rapidly distinguishing different types of polymers and their products. In addition, the signals of the additives in the polymer products, including antioxidants and plasticizers, were also detected before the TG temperature reached T_max .

Avatar-like body imaging of dermal exposure to melamine in factory workers analyzed by ambient mass spectrometry

Ambient mass spectrometry thermal desorption-electrospray ionization/mass spectrometry (TD-ESI/MS) can rapidly identify chemicals without pretreatment of biological samples. This study used a rapid semi-quantitative TD-ESI/MS screening technique for the probe skin sampling of melamine workers occupationally exposed to different ambient melamine concentrations to create avatar-like body images, which were then used to study temporal and dynamic changes in nephrotoxic melamine exposure. We enrolled four voluntary melamine workers from one factory, each from one of four worksites. Melamine exposure was highest in manufacturing and molding, followed by grinding and polishing, packing, and administration, the lowest. Skin samples were collected Friday (end-of-shift) and Monday (pre-shift). Early morning one-spot urine samples were also collected right after skin sampling. 2198 probe skin samples were collected and subjected to semi-quantitative TD-ESI/MS analyses of melamine chemical within 40 h. After normalization, converted body image scores revealed exposure to be highest in the manufacturing worker on Friday and lowest in the administrative worker on Monday. The absolute differences (Friday minus Monday) of normalized body image scores were all significantly positive in each individual worker and across all four workers (permutation test, all p-values < 0.002). The slope estimates of the linear regression line between body image scores and urinary melamine levels were 0.81 (p-value = 0.008). We concluded that this fast and non-invasive technique can potentially be used to study temporal and dynamic changes in exposure to occupational hazards. A future study of developing an automatic and reproducible TD-ESI/MS sampling platform is needed.

Thermal desorption ambient ionization mass spectrometry for emergency toxicology

In the emergency department, it is important to rapidly identify the toxic substances that have led to acute poisoning because different toxicants or toxins cause poisoning through different mechanisms, requiring disparate therapeutic strategies and precautions against contraindicating actions, and diverse directions of clinical course monitoring and prediction of prognosis. Ambient ionization mass spectrometry, a state-of-the-art technology, has been proved to be a fast, accurate, and user-friendly tool for rapidly identifying toxicants like residual pesticides on fruits and vegetables. In view of this, developing an analytical platform that explores the application of such a cutting-edge technology in a novel direction has been initiated a research program, namely, the rapid identification of toxic substances which might have caused acute poisoning in patients who visit the emergency department and requires an accurate diagnosis for correct clinical decision-making to bring about corresponding data-guided management. This review includes (i) a narrative account of the breakthrough in emergency toxicology brought about by the advent of ambient ionization mass spectrometry and (ii) a thorough discussion about the clinical implications and technical limitations of such a promising innovation for promoting toxicological tests from tier two-level to tier one level.

Rapid Characterization of Bacterial Lipids with Ambient Ionization Mass Spectrometry for Species Differentiation

Ambient ionization mass spectrometry (AIMS) is both labor and time saving and has been proven to be useful for the rapid delineation of trace organic and biological compounds with minimal sample pretreatment. Herein, an analytical platform of probe sampling combined with a thermal desorption–electrospray ionization/mass spectrometry (TD-ESI/MS) and multivariate statistical analysis was developed to rapidly differentiate bacterial species based on the differences in their lipid profiles. For comparison, protein fingerprinting was also performed with matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) to distinguish these bacterial species. Ten bacterial species, including five Gram-negative and five Gram-positive bacteria, were cultured, and the lipids in the colonies were characterized with TD-ESI/MS. As sample pretreatment was unnecessary, the analysis of the lipids in a bacterial colony growing on a Petri dish was completed within 1 min. The TD-ESI/MS results were further performed by principal component analysis (PCA) and hierarchical cluster analysis (HCA) to assist the classification of the bacteria, and a low relative standard deviation (5.2%) of the total ion current was obtained from repeated analyses of the lipids in a single bacterial colony. The PCA and HCA results indicated that different bacterial species were successfully distinguished by the differences in their lipid profiles as validated by the differences in their protein profiles recorded from the MALDI-TOF analysis. In addition, real-time monitoring of the changes in the specific lipids of a colony with growth time was also achieved with probe sampling and TD-ESI/MS. The developed analytical platform is promising as a useful diagnostic tool by which to rapidly distinguish bacterial species in clinical practice.

Corrigendum: Isobaric Tags for Relative and Absolute Quantitation Identification of Blood Proteins Relevant to Paroxetine Response in Patients With Major Depressive Disorder

[This corrects the article DOI: 10.3389/fpsyt.2022.577857.].

Isobaric Tags for Relative and Absolute Quantitation Identification of Blood Proteins Relevant to Paroxetine Response in Patients With Major Depressive Disorder

OBJECTIVES

Isobaric tags for relative and absolute quantitation (iTRAQ) is a proteomic investigation that could be utilized for rapid identification and quantification of proteins, which we would use to identify differentially expressed proteins in treatment responsive patients with major depressive disorder (MDD).

METHODS

Six treatment responsive patients of MDD were recruited, and their peripheral blood mononuclear cell (PBMC) were collected before and after 4 weeks of paroxetine treatment. iTRAQ and Mascot search engine were used to detect differentially expressed proteins, which were then validated by Western blot.

RESULTS

Two thousand one hundred and fifty three proteins were screened, and seven proteins showed differences of more than two-fold and 62 proteins with a differences of less than two-fold. Six proteins with commercially available antibodies were identified, and were validated by Western blot in 10 paroxetine responsive MDD patients. Putative hydroxypyruvate isomerase (HYI), eukaryotic translation initiation factor 4H (eIF4H), and RNA binding motif 8A (RBM8A) had statistically significant differences before and after treatment in the validation. Data are available via ProteomeXchange with identifier PXD028947.

CONCLUSIONS

By using iTRAQ and Western blot, we were able to identify HYI, eIF4H, and RAM8a to be the potential predictors of paroxetine treatment response in patients with MDD. This finding could help establish future individualized medicine.

Molecular Mapping of Sebaceous Squalene by Ambient Mass Spectrometry

Squalene (SQ), a highly unsaturated sebaceous lipid, plays an important role in protecting human skin. To better understand the role of SQ in clinical medicine, an efficient analytical approach is needed to comprehensively study the distribution of SQ on different parts of the skin. In this study, sebaceous lipids were collected from different epidermal areas of a volunteer with sampling probes. Thermal desorption-electrospray ionization/mass spectrometry (TD-ESI/MS) was then used to characterize the lipid species on the probes, and each TD-ESI/MS analysis was completed within a few seconds without any sample pretreatment. The molecular mapping of epidermal squalene on whole-body skin was rendered by scaling the peak area of the extracted ion current (EIC) of SQ based on a temperature color gradient, where colors were assigned to the 1357 sampling locations on a 3D map of the volunteer. The image showed a higher SQ distribution on the face than any other area of the body, indicating the role of SQ in protecting facial skin. The results were in agreement with previous studies using SQ as a marker to explore sebaceous activity. The novelty and significance of this work are concluded as two points: (1) direct and rapid detection of all major classes of sebaceous lipids, including the unsaturated hydrocarbons (SQ) and nonpolar lipids (e.g., cholesterol). The results are unique compared to other conventional and ambient ionization mass spectrometry methods and (2) this is the first study to analyze SQ distribution on the whole-body skin by a high-throughput approach.

Characterization of Potential Protein Biomarkers for Major Depressive Disorder Using Matrix-Assisted Laser Desorption Ionization/Time-of-Flight Mass Spectrometry

Matrix-assisted laser desorption ionization/time-of-flight (MALDI-TOF) mass spectrometry is a sensitive analytical tool for characterizing various biomolecules in biofluids. In this study, MALDI-TOF was used to characterize potential plasma biomarkers for distinguishing patients with major depressive disorder (MDD) from patients with schizophrenia and healthy controls. To avoid interference from albumin—the predominant protein in plasma—the plasma samples were pretreated using acid hydrolysis. The results obtained by MALDI-TOF were also validated by electrospray ionization-quadrupole time-of-flight (ESI-QTOF) mass spectrometry. The analytical results were further treated with principal component analysis (PCA), hierarchical clustering analysis (HCA), and receiver operating characteristic (ROC) curve analysis. The statistical analyses showed that MDD patients could be distinguished from schizophrenia patients and healthy controls by the lack of apolipoprotein C1 (Apo C1), which, in fact, was detected in healthy controls and schizophrenia patients. This protein is suggested to be a potential plasma biomarker for distinguishing MDD patients from healthy controls and schizophrenia patients. Since sample preparation for MALDI-TOF is very simple, high-throughput plasma apolipoprotein analysis for clinical purposes is feasible.

Obtaining molecular imagings of pesticide residues on strawberry surfaces with probe sampling followed by ambient ionization mass spectrometric analysis

Thermal desorption-electrospray ionization tandem mass spectrometry (TD-ESI/MS/MS) was used to rapidly characterize the residual pesticides collected on the surface of a strawberry with a metallic probe. Twelve pesticides, including nine fungicides and three miticides, were detected; the results were validated by comparison with results that used solvent extraction followed by gas chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry analyses. The distribution of pesticide residues on a strawberry's surface was explored by collecting multiple samples using probes from 40 positions on the strawberry, with the collected samples being analyzed with TD-ESI/MS/MS. The obtained molecular information was used to construct mass spectrometry imaging of the strawberry's pesticide residues.

Wire Desorption Combined with Electrospray Ionization Mass Spectrometry: Direct Analysis of Small Organic and Large Biological Compounds

A novel atmospheric pressure ionization mass spectrometry based on wire desorption and electrospray ionization (WD-ESI) for direct analysis was developed to characterize chemical compounds with different polarities and thermal stabilities at atmospheric pressure. This technique is a variant of the thermal desorption electrospray ion source developed by Shiea et al. One large improvement is that the heating speed (>500 °C/s) of the thermal desorption in this work is extremely fast, using a self-heating metal wire, with which sample solution can splash from the surface to form small droplets and thus the analytes can be protected from thermal decomposition. With this feature, we have successfully achieved soft ionization of highly polar organic and biological compounds such as aflatoxin, small peptides, and even large proteins from complex matrices. The simple structure and self-cleaning capability of the WD-ESI source make it ideal for on-site screening in various applications such as food safety and biodrug testing, especially when coupled with a transportable mass spectrometer.

Role of Low-Density Lipoprotein in Early Vascular Aging Associated With Systemic Lupus Erythematosus

OBJECTIVE

Patients with systemic lupus erythematosus (SLE) often have atherosclerotic complications at a young age but normal low-density lipoprotein (LDL) levels. This study was undertaken to investigate the role of LDL composition in promoting early vascular aging in SLE patients.

METHODS

Plasma LDL from 45 SLE patients (SLE-LDL) and from 37 normal healthy controls (N-LDL) was chromatographically divided into 5 subfractions (L1-L5), and the subfraction composition was analyzed. Correlations between subfraction levels and signs of early vascular aging were assessed. Mechanisms of lipid-mediated endothelial dysfunction were explored using in vitro assays and experiments in apoE^-/- mice.

RESULTS

The L5 percentage was increased 3.4 times in the plasma of SLE patients compared with normal controls. This increased percentage of SLE-L5 was positively correlated with the mean blood pressure (r = 0.27, P = 0.04), carotid intima-media thickness (IMT) (right carotid IMT, r = 0.4, P = 0.004; left carotid IMT, r = 0.36, P = 0.01), pulse wave velocity (r = 0.29, P = 0.04), and blood levels of CD16+ monocytes (r = 0.35, P = 0.004) and CX3CL1 cytokines (r = 0.43, P < 0.001) in SLE patients. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis revealed that plasma levels of lysophosphatidylcholine (LPC) and platelet-activating factor (PAF) were increased in SLE-LDL and in the SLE-L5 plasma subfraction. Injecting SLE-LDL, SLE-L5, or LPC into young, male apoE^-/- mice caused increases in plasma CX3CL1 levels, aortic fatty-streak areas, aortic vascular aging, and macrophage infiltration into the aortic wall, whereas injection of N-LDL or SLE-L1 had negligible effects (n = 3-8 mice per group). In vitro, SLE-L5 lipid extracts induced increases in CX3CR1 and CD16 expression in human monocytes; synthetic PAF and LPC had similar effects. Furthermore, lipid extracts of SLE-LDL and SLE-L5 induced the expression of CX3CL1 and enhanced monocyte-endothelial cell adhesion in assays with bovine aortic endothelial cells.

CONCLUSION

An increase in plasma L5 levels, not total LDL concentration, may promote early vascular aging in SLE patients, leading to premature atherosclerosis.

Rapid identification of organophosphorus pesticides on contaminated skin and confirmation of adequate decontamination by ambient mass spectrometry in emergency settings

RATIONALE

Dermal exposure to pesticides may cause severe intoxication and even result in a fatal outcome. To expedite rescue in the emergency department, it is mandatory to develop a point-of-care analytical method for immediate identification of pesticides on the skin of exposed personnel, and to perform immediate dermal decontamination to prevent further harm and optimize the chance for full clinical recovery.

METHODS

Four of the most commonly used highly toxic pesticides that contaminate the skin were rapidly characterized by thermal desorption electrospray ionization mass spectrometry. The technique was also applied to confirm the completeness of pesticide decontamination from the skin. Pesticide sampling, desorption, ionization, and detection altogether took less than 30 s. In addition, different fabrics of protective garments worn by farmers were assessed with this efficient ambient mass spectrometric technique for their protective capabilities against dermal exposure to pesticides, and scanning electron microscopy was used to observe their different microstructures. The decontaminating efficacies of different cleansing agents for these skin contaminants were also evaluated by this technical platform.

RESULTS

The repeatability of this method had a low relative standard deviation (<22%) for the detection of pesticides on the surface of swine skin. The detection limits of the pesticides in solution were found to be in the range of 3-20 ng/mL. Linearity was observed between the signal intensities and the concentrations of the four pesticides in solution within the range of 50 ng/mL to 50 μg/mL (R² between 0.9921 and 0.9966). In addition, it was found that PVC fabric is optimal in preventing skin contamination by fenthion and detergent had the best efficiency for fenthion decontamination.

CONCLUSIONS

Since the whole analytical process is extremely fast, this technique allows early point-of-care identification of contaminating pesticides on the skin of exposed patients in the emergency room, as well as rapid assessment of the adequacy of decontamination.

Rapid quantification of acetaminophen in plasma using solid-phase microextraction coupled with thermal desorption electrospray ionization mass spectrometry

RATIONALE

Solid-phase microextraction coupled with thermal desorption electrospray ionization tandem mass spectrometry (SPME-TD-ESI-MS/MS) is proposed as a novel method for the rapid quantification of acetaminophen in plasma samples from a pharmacokinetics (PK) study.

METHODS

Traces of acetaminophen were concentrated on commercial fused-silica fibers coated with a polar polyacrylate (PA) polymer using direct immersion SPME. No agitation, heating, addition of salt, or adjustment of the pH of the sample solution was applied during the extraction. Any acetaminophen absorbed on the SPME fibers was subsequently desorbed and detected by TD-ESI-MS/MS.

RESULTS

Parameters of the absorption, sensitivity, reproducibility, and linearity for the SPME-TD-ESI-MS/MS method were evaluated. The time required to complete a TD-ESI-MS/MS analysis was less than 30 seconds. Matrix-matching calibration was performed to calculate the concentration of acetaminophen in the sample. A linear calibration curve with a concentration range of 100-10,000 ng/mL was constructed to calculate the quantity of acetaminophen. The SPME-TD-ESI-MS quantification results for acetaminophen in plasma were in good agreement with those obtained by the conventional LC/MS/MS method.

CONCLUSIONS

With the proposed method, a 10-min SPME time was enough to achieve the lower limit of quantitation (i.e. 100 ng/mL) and for a complete PK profiling of acetaminophen. A shorter extraction time could be achieved by applying agitation, heating, adding salt, or adjusting the pH of the sample solution to enhance analyte absorption efficiency. The time required to detect acetaminophen on the SPME fiber was less than 30 s, allowing the rapid quantification of acetaminophen in plasma with good accuracy.

Identification and characterization of unknown degradation impurities in beclomethasone dipropionate cream formulation using HPLC, ESI-MS and NMR

The present study focuses on identifying the degradation profile and pathways of unknown impurities from beclomethasone dipropionate (BDP) topical cream formulation reported under accelerated stability conditions. Six degradation impurities were observed during the accelerated stability testing of BDP topical cream formulation, and these thermally labile degradation impurities were primarily identified using a simple, effective and mass compatible isocratic reversed-phase high-performance liquid chromatography with ultraviolet detection method. The degradation impurities found in this sample were of very low concentration levels, thus the concentration of these impurities in the sample was enriched by mimicking the thermal degradation conditions to structurally elucidate the unknown impurities. These BDP thermal degradation impurities were isolated using preparative liquid chromatography and followed by pre-concentration using rota-vapour. Further, the collected thermal degradation impurities were characterized using ESI-MS, and the major impurity was identified using ¹H and C¹³ NMR spectroscopy, and DEPT technique. Plausible degradation pathway and mechanism of each impurity from BDP has been proposed based on the obtained mass and NMR spectral data. Thus, the present method is simple and suitable to be applied towards BDP assay in various formulations, and also to investigate the thermal stability and degradation kinetics of the final drug product.

Direct and rapid characterization of illicit drugs in adulterated samples using thermal desorption electrospray ionization mass spectrometry

Foods and drinks have been adulterated with illicit drugs to facilitate criminal activities. Unfortunately, conventional analytical methods are incapable of rapidly characterizing these drugs in samples, as serious interferences from sample matrices must be removed through tedious and time-consuming pretreatment. Ambient ionization mass spectrometry (AMS) generally does not require sample pretreatment and is thus a suitable tool for directly and rapidly detecting illicit drugs in samples in different physical states. In this study, thermal desorption electrospray ionization mass spectrometry (TD-ESI/MS), an AMS technique, was utilized to efficiently characterize illicit drugs spiked in samples including drinks, powders, and jelly candies. To perform sensitive analysis, the mass analyzer was operated in multiple reaction monitoring mode to monitor the molecular and fragment ions of the target analytes. The time required to complete a typical TD-ESI/MS analysis was less than 30 s. The limits of detection (LODs) for illicit drugs were found to be 100 ppb in drinks, 100–1000 ppb in instant powders, and 1.3–6.5 ng/mm² on stamp surfaces. FM2 and nitrazepam laced in the inner layer of a jelly candy were detected by TD-ESI/MS, showcasing the advantage of the technique for direct and rapid analysis as opposed to conventional methods.

Ambient mass spectrometry for rapid diagnosis of psychoactive drugs overdose in an unstable patient

A 25-year-old man suffered from consciousness change was sent to our emergency department by friends who reported that they were not sure what had happened to him. Physical examination revealed bilateral pupils dilatation, lethargy, slurred speech, and ataxia. Computer-aided tomographic scan of the brain revealed no definite evidence of intracranial lesions. Routine laboratory tests revealed total physiological turmoil. Despite immediate commencement of aggressive treatment, the patient's condition deteriorated long before the traditional drug screen provided an answer for the identities of the multiple drugs overdose. It ended up with the need for cardiopulmonary resuscitation, but in vain. At the end of the tragic event, under the suggestion of a colleague, a portion of the patient's urine specimen was sent to our university esoteric laboratory for rapid analysis by means of a newly-developed thermal desorption-electrospray ionization-mass spectrometry. Ketamine, 3,4-methylenedioxymethamphetamine, and 3,4-methylenedioxyamphetamine were identified in the urine sample within 30s. Conventional toxicological testing techniques like gas chromatography-mass spectrometry or liquid chromatography-mass spectrometry are currently used for identifying abused drugs. One concern is their time-consuming sample pretreatment which leads to relatively low efficiency in terms of turnaround time for revealing the identity of the consumed drugs particularly when the patients are severely overdosed. We learned a lesson from this case that a more efficient toxicological identification technique is essential to expedite the process of emergency care when the patients are so heavily overdosed that they are under critical life-threatening conditions.

Urinary Concentrations of Triclosan, Benzophenone-3, and Bisphenol A in Taiwanese Children and Adolescents

The purpose of this study was to determine the levels of urinary triclosan (TCS), benzophenone-3 (BP-3), and bisphenol A (BPA) in 52 children and 71 adolescents. The effects of age and sex on the levels of urinary TCS, BP-3, and BPA were explored, respectively. Results demonstrated the overall detection rates of urinary TCS, BP-3, and BPA were 18.7%, 8.1%, and 49.6%, respectively. The females had higher TCS concentrations than males (p = 0.051). The detection rate of urinary BP-3 in females (12.3%) was higher than that in males (0%) (p = 0.015). Moreover, the detection rate of urinary BP-3 in adolescents (14.1%) was higher than that in children (0%) (p = 0.005). For children, no urinary BP-3 was found. There were no differences in detection rates and concentrations of urinary TCS, BP-3, and BPA between males and females, respectively. For adolescents, urinary BP-3 was only found in the females. Urinary TCS levels in females were higher than those in males (p = 0.047). The present study showed that urinary TCS concentrations in females were significantly higher than those in males, respectively. In addition, BP-3 was only detected in urine samples of female adolescents. Sex and age were the important factors influencing urinary TCS and BP-3 concentrations.

Rapid and simple analysis of disease-associated biomarkers of Taiwanese patients with schizophrenia using matrix-assisted laser desorption ionization mass spectrometry

BACKGROUND

Matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS) is an extremely sensitive analytical tool for characterizing biological compounds in bio samples. In this study, we applied MALDI-TOF MS to assess potential protein biomarkers in the peripheral blood mononuclear cells (PBMCs) of patients with schizophrenia in the acute phase, recovery phase and healthy controls in Taiwan.

METHODS

We recruited 40 participants, including 20 pairs of patients diagnosed with schizophrenia in the acute phase, after four-week treatment with drug in the recovery phase, and 20 healthy controls. The schizophrenic patients were diagnosed using Structured Clinical Interview for DSM-IV Axis I Disorders (SCID), and severity was assessed by a positive and negative symptom scale at baseline and at endpoint following four-week treatment with drug. The patients' PBMCs biomarkers were rapidly measured using a technique that combines MALDI-TOF MS and principle component analysis. A receiver operating characteristic curve was created for the evaluated biomarker.

RESULTS

Significant differences in α-defensins 1-3 were found between the patients in acute phase with schizophrenia and the healthy controls, but not between the schizophrenic patients in recovery phase and healthy controls or between the schizophrenic patients in acute phase and in recovery phase.

CONCLUSIONS

α-Defensins can be biomarkers of Taiwanese patients with schizophrenia, thus supporting the hypothesis that the inflammatory response and immunity system is correlated with the pathophysiology of schizophrenia. Moreover, the result also implies that α-defensins may be related in schizophrenia-associated disease not in efficacy of drug-treatment.

Flame Atmospheric Pressure Chemical Ionization Coupled with Negative Electrospray Ionization Mass Spectrometry for Ion Molecule Reactions

Flame atmospheric pressure chemical ionization (FAPCI) combined with negative electrospray ionization (ESI) mass spectrometry was developed to detect the ion/molecule reactions (IMRs) products between nitric acid (HNO₃) and negatively charged amino acid, angiotensin I (AI) and angiotensin II (AII), and insulin ions. Nitrate and HNO₃-nitrate ions were detected in the oxyacetylene flame, suggesting that a large quantity of nitric acid (HNO₃) was produced in the flame. The HNO₃ and negatively charged analyte ions produced by a negative ESI source were delivered into each arm of a Y-shaped stainless steel tube where they merged and reacted. The products were subsequently characterized with an ion trap mass analyzer attached to the exit of the Y-tube. HNO₃ showed the strongest affinity to histidine and formed (M_histidine-H+HNO₃)^- complex ions, whereas some amino acids did not react with HNO₃ at all. Reactions between HNO₃ and histidine residues in AI and AII resulted in the formation of dominant [M_AI-H+(HNO₃)]^- and [M_AII-H+(HNO₃)]^- ions. Results from analyses of AAs and insulin indicated that HNO₃ could not only react with basic amino acid residues, but also with disulfide bonds to form [M-3H+(HNO₃)_n]^3- complex ions. This approach is useful for obtaining information about the number of basic amino acid residues and disulfide bonds in peptides and proteins. Graphical Abstract ᅟ.

Rapid characterization of trace aflatoxin B1 in groundnuts, wheat and maize by dispersive liquid-liquid microextraction followed by direct electrospray probe tandem mass spectrometry

RATIONALE

Aflatoxins are poisonous and cancer-related chemical compounds commonly found in crops and plants. Aflatoxin B₁ is the most toxic compound among aflatoxins and has been classified as group 1 carcinogenic to humans, especially in liver cancer. Herein, an ambient mass spectrometric method was developed for rapid characterization of trace aflatoxin B₁ in peanuts.

METHODS

Direct electrospray probe tandem mass spectrometry (DEP-MS/MS) was used to detect aflatoxin B₁ in peanuts. To avoid the matrix effect, the aflatoxin B₁ in the samples was extracted and concentrated by dispersive liquid-liquid microextraction. The mass spectrometer was operated in the positive ion mode to monitor the intact molecular ion (m/z 313, MH⁺ ) and product ion (m/z 241) of aflatoxin B₁ using multiple reaction monitoring.

RESULTS

Since no clean-up procedure of the sample was required, the sampling step and the subsequent mass spectrometric detection of the aflatoxin B₁ was completed in less than 5 min. The limit of detection of aflatoxin B₁ is at the sub-ppb level. The results obtained by DEP-MS/MS were also validated by liquid chromatography/tandem mass spectrometry (LC/MS/MS). Recovery of aflatoxin B₁ in the sample was evaluated by analyzing spiked aflatoxin B₁ with LC/MS/MS to be 85% and DEP-MS/MS to be 84%.

CONCLUSIONS

DEP-MS/MS combined with a simple dispersive liquid-liquid microextraction procedure was successfully used for the quantitative analysis of AFB₁ in nut samples. Due to its high efficiency, it is promising in providing important toxicological information for food safety in the real world. Copyright © 2017 John Wiley & Sons, Ltd.

Rapid Identification of Psychoactive Drugs in Drained Gastric Lavage Fluid and Whole Blood Specimens of Drug Overdose Patients Using Ambient Mass Spectrometry

Psychoactive drug overdoses are life-threatening and require prompt and proper treatment in the emergency room to minimize morbidity and mortality. Prompt identification of the ingested psychoactive drugs is challenging, since witness recall is unreliable and patients' symptoms do not necessarily explain their loss of consciousness. Gas and liquid chromatography mass spectrometric analyses have been the traditionally employed methods to detect and identify abused substances; however, these techniques are time-consuming and labor-intensive. In this study, thermal desorption electrospray ionization mass spectrometry, an ambient mass spectrometric technique, was applied to rapidly characterize flunitrazepam, lysergic acid diethylamide, and 3,4-methylenedioxy-methamphetamine in drained gastric lavage fluid, and ketamine, cocaine, amphetamine and norketamine in whole blood samples. No pretreatment of the gastric lavage fluid specimens was required and the entire analytical process took less than 30 s per specimen. Liquid-liquid extraction, followed by centrifugation, was performed on the whole blood samples. The corresponding compounds were identified through matching the obtained mass spectrometric data with those provided by commercial databases. The limits-of-detection of the tested drugs in both drained gastric lavage fluid and whole blood samples are at sub ppm levels. This is sensitive enough for emergency medical application, since the quantities of medications ingested by overdosed abusers are much higher than the amounts that were tested.

Removal of Diethylhexyl Phthalate from Hands by Handwashing: Evidence from Experimental N-of-1 and Crossover Designs

Phthalate exposure through skin is often neglected due to the small quantity and limited dermal absorption rate. However, free phthalate can be ingested by hand-to-mouth action or by contact with food. To evaluate the effectiveness in removing phthalate exposure on hand, we compare here the removal efficiency of di-(2-ethylhexyl)phthalate (DEHP) on hands by handwashing with soap-and-water versus water-only. In two three-day N-of-1 trials, residual DEHP was measured in a single female adult who washed exposed hands with soap-and-water or water-only. Subsequently, a crossover study was performed by randomly assigning another 28 subjects equally to wash with soap-and-water or with water-only, and then each one received the other treatment 24 hrs later. In the N-of-1 trials, mean DEHP removal rates range from 95.9% (SD = 0.1%) to 97.0% (SD = 2.5%) for soap-and-water handwashes, and 1.8% (SD = 0.1%) to 7.0% (SD = 0.3%) (n = 3) for water-only. In the crossover study, mean removal rate was 94.6% (SD = 6.5%) for handwashing with soap-and-water (n = 28) and 8.7% (SD = 5.7%) for water-only (n = 28). We concluded that handwashing with soap-and-water removes 80% more DEHP than handwashing with water alone, and may be a cost-effective way of removing other endocrine disruptors from hands.

Desorption Flame-Induced Atmospheric Pressure Chemical Ionization Mass Spectrometry for Rapid Real-World Sample Analysis

Flame-induced atmospheric pressure chemical ionization (FAPCI) is a solvent and high voltage-free APCI technique. It uses a flame to produce charged species that reacts with analytes for ionization, and generates intact molecular ions from organic compounds with minimal fragmentation. In this study, desorption FAPCI/MS was developed to rapidly characterize thermally stable organic compounds in liquid, cream, and solid states. Liquid samples were introduced into the ion source through a heated nebulizer, and the analytes formed in the heated nebulizer reacted with charged species in the source. For cream and solid sample analysis, the samples were positioned near the flame of the FAPCI source for thermal desorption and ionization. This approach provided a useful method to directly characterize samples with minimal pretreatment. Standards and real-world samples, such as drug tablets, ointment, and toy were analyzed to demonstrate the capability of desorption FAPCI/MS for rapid organic compound analysis.

Rapid detection of alteration of serum IgG in patients with schizophrenia after risperidone treatment by matrix-assisted laser desorption ionization/time-of-flight mass spectrometry

RATIONALE

The aim of the study was to use a technique that combines acid hydrolysis and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS) in order to detect the serum biomarkers of patients diagnosed with schizophrenia both before and after four-week antipsychotic treatment with risperidone.

METHODS

During this study's two-year period, inpatients were diagnosed with schizophrenia using the Structured Clinical Interview for DSM-IV Axis I Disorders. Severity was then evaluated using the Positive and Negative Syndrome Scale both at baseline and at endpoint following four-week treatment with risperidone. The patients' serum biomarkers were quickly measured using acid hydrolysis and MALDI-TOF MS. The resulting peptides were then analyzed using MALDI-TOF MS. We constructed a receiver operating characteristic (ROC) curve for the evaluated biomarkers.

RESULTS

We recruited 20 pairs of participants for this study. The experimental group was treated with serum protein with HCl for 10 minutes to effectively hydrolyze abundant proteins. The target peptide, the immunoglobulin gamma chain (IgG), was then rapidly detected using this manner. A significant difference was found in the IgG levels of patients with schizophrenia before and after antipsychotic treatment. We constructed a ROC curve based on the IgG, and the area under said curve was 0.969. In comparison to conventional detection protocols, this method takes only minutes to complete and is also less costly.

CONCLUSIONS

This study found that applying acid hydrolysis with MALDI-TOF MS technology could rapidly differentiate serum IgG levels in patients with schizophrenia before and after being treated with risperidone. This IgG difference may enhance the understanding of mechanism of antipsychotic treatment of schizophrenia. Copyright © 2016 John Wiley & Sons, Ltd.

Rapid point-of-care identification of oral medications in gastric lavage content by ambient mass spectrometry in the emergency room

RATIONALE

Acute poisoning should be handled with high efficiency in order to minimize morbidity and mortality in the emergency room. Unfortunately, history-taking and physical examination are not always reliable. Mis-swallowing of oral medications is common in the pediatric group. This study aimed at developing a rapid point-of-care ambient mass spectrometric method for the early identification of ingested oral medications in gastric lavage content.

METHODS

Four different types of oral medications that are most commonly mis-swallowed by children were diluted to different concentrations. Each of these chemical solutions was mixed with human gastric lavage content. A direct metallic sampling probe was dipped into the solution. It was then inserted promptly into the thermal desorption electrospray ionization source to carry out ionization and subsequent mass spectrometric analysis of the medications. The corresponding compounds were identified through matching of the obtained mass spectrometric data with those provided by well-established databases.

RESULTS

Since no pretreatment of the specimen was required, the sampling step, and the subsequent thermal desorption electrospray ionization and mass spectrometric detection of the medications were completed within 30 s. Mass spectra were obtained for four different kinds of oral medication. The limit-of-detection of the four tested oral medications in gastric lavage content is at sub-ppm level, which is sensitive enough for emergency medicine applications since the quantities of medications ingested by pediatric patients are usually much higher.

CONCLUSIONS

Thermal desorption electrospray ionization mass spectrometry, with informational support provided by an online mass spectral database, allows for early point-of-care identification of mis-swallowed oral medications in the evacuated gastric lavage contents obtained from gastric lavage of patients in the emergency room, and it is promising in providing important toxicological information to ensure the appropriateness of the subsequent medical management. Copyright © 2016 John Wiley & Sons, Ltd.

Flame-induced atmospheric pressure chemical ionization mass spectrometry

RATIONALE

Charged species such as formylium (CHO(+) ), hydronium (H3 O(+) ), and water clusters [H3 O(+) (H2 O)n ] are commonly found in flames. These highly reactive species can react with analytes via ion-molecule reactions (IMRs) to form analyte ions. A new mass spectrometric technique, named flame-induced atmospheric pressure chemical ionization mass spectrometry (FAPCI-MS), was developed to characterize organic compounds via these mechanisms.

METHODS

A commercial corona-discharge atmospheric pressure chemical ionization (APCI) source was modified by replacing the corona needle with a flame to make a FAPCI source. Liquid samples were vaporized in a heated tube and delivered to the IMRs region by nitrogen to react with the charged species generated by a flame. Analytes on surfaces were directly desorbed and ionized by a flame using the technique called desorption-FAPCI-MS (DFAPCI-MS).

RESULTS

Intact molecular ions of various chemical and biological compounds were successfully characterized by FAPCI-MS. The FAPCI mass spectra are nearly identical to those obtained by traditional APCI-MS. The limit of detection (LOD) of reserpine by FAPCI-MS was 50 μg L(-1) with a linear calibration curve (R(2) = 0.9947) from 100 μg L(-1) to 10 mg L(-1) . The LOD for ketamine by DFAPCI-MS was estimated to be less than 0.1 ng.

CONCLUSIONS

In FAPCI, analytes are not incinerated but vaporized and introduced into the ion source to react with the reactive charged species generated by a flame. The features of the FAPCI source include: configuration is very simple, operation is easy, high voltage or inert gas is unnecessary, and the source is maintenance free. Various combustible gases, solvents and solids are useful flame fuels for FAPCI. Copyright © 2016 John Wiley & Sons, Ltd.

Rapid identification of pesticides in human oral fluid for emergency management by thermal desorption electrospray ionization/mass spectrometry

Self-poisoning with pesticides accounts for approximately one-third of all suicides worldwide. To expedite rescue in the emergency department, it is essential to develop a point-of-care analytical method for rapid identification of ingested pesticides. In this study, five of the most common pesticides ingested by self-poisoning patients in Taiwan were analyzed from oral fluid samples. Pesticide-oral fluid mixtures were applied on a cotton swab and then transferred into methanol. A metallic probe was used to sample the methanol solution for subsequent thermal desorption-electrospray ionization mass spectrometry analysis. Altogether, pesticide sampling, transfer, desorption, ionization, and detection took less than 1 min. The reproducibility of this method (n = 6) was shown in the observed low-relative standard deviation (<7%) in the detection of pesticide in oral fluid. The detection limits of the pesticides in oral fluid obtained from four human subjects by thermal desorption-electrospray ionization mass spectrometry were between 1-10 ppb with relative standard deviation 10.7%. Moreover, in this study, linear responses of five pesticides in oral fluid with concentrations between 1 ppb-1 ppm (R2 between 0.9938 and 0.9988) were observed. As the whole analytical process is extremely short, this technique allows for early non-invasive point-of-care identification of pesticides in the oral fluid of self-poisoning patients in the emergency room, providing important toxicological information for decision-making during critical resuscitation.

Depth profiling of inks in authentic and counterfeit banknotes by electrospray laser desorption ionization/mass spectrometry

Electrospray laser desorption ionization is an ambient ionization technique that generates neutrals via laser desorption and ionizes those neutrals in an electrospray plume and was utilized to characterize inks in different layers of copy paper and banknotes of various currencies. Depth profiling of inks was performed on overlapping color bands on copy paper by repeatedly scanning the line with a pulsed laser beam operated at a fixed energy. The molecules in the ink on a banknote were desorbed by irradiating the banknote surface with a laser beam operated at different energies, with results indicating that different ions were detected at different depths. The analysis of authentic $US100, $100 RMB and $1000 NTD banknotes indicated that ions detected in 'color-shifting' and 'typography' regions were significantly different. Additionally, the abundances of some ions dramatically changed with the depth of the aforementioned regions. This approach was used to distinguish authentic $1000 NTD banknotes from counterfeits. Copyright © 2015 John Wiley & Sons, Ltd.

Letter: Supermetallization of peptides and proteins with tetravalent metal Th(IV)

Supermetallization is the recently observed phenomenon of the formation of complex ions of peptide-metal in the gas phase when the peptide accepts an unexpectedly large number of metal atoms. It has been found that supermetallization takes place during electrospray ionization when charged droplets are evaporating at relatively high temperature (ca 400°C). In the present paper, we demonstrate supermetallized complexes of small protein ubiquitin and two peptides with Th(IV). We have observed complexes of ubiquitin with up to five thorium atoms, and attaching each Th(IV) requires the removal of four hydrogen atoms. To our knowledge, this is the first demonstration of gas-phase complexes of peptides and proteins with tetravalent metal atoms..

Relationship of urinary phthalate metabolites with serum thyroid hormones in pregnant women and their newborns: a prospective birth cohort in Taiwan

Background

The purpose of this study was to examine the relationship of phthalates exposure with thyroid function in pregnant women and their newborns.

Methods

One hundred and forty-eight Taiwanese maternal and infant pairs were recruited from E-Da hospital in southern Taiwan between 2009 and 2010 for analysis. One-spot urine samples and blood samples in the third trimester of pregnant women and their cord blood samples at delivery were collected. Nine phthalate metabolites in urine were determined by triple quadrupole liquid chromatography tandem mass spectrometry, whereas serum from pregnant women and their cord blood were used to measure thyroid profiles (thyroid-stimulating hormone [TSH], thyroxine, free thyroxine, and triiodothyronine) by radioimmunoassay.

Results

Median levels of urinary mono-n-butyl phthalate, mono-ethyl phthalate, and mono-(2-ethyl-5-oxohexyl) phthalate (μg/g creatinine) were the three highest phthalate metabolites, which were 37.81, 34.51, and 21.73, respectively. Using Bonferroni correction at a significance of < 0.006, we found that urinary mono-benzyl phthalate (MBzP) levels were significantly and negatively associated with serum TSH in cord blood (β = -2.644, p = 0.003).

Conclusions

Maternal urinary MBzP, of which the parental compound is butylbenzyl phthalate, may affect TSH activity in newborns. The alteration of thyroid homeostasis by certain phthalates in the early life, a critical period for neurodevelopment, is an urgent concern.