Determination of sedatives and adrenergic blockers in blood meal using accelerated solvent extraction and Orbitrap mass spectrometry

Development of the Chromatographic Method for Simultaneous Determination of Azaperone and Azaperol in Animal Kidneys and Livers

A precise and accurate method for the simultaneous determination of azaperone and azaperol in meat tissues has been developed. This paper describes the first method to be so fast, simple, and useful, especially for many laboratories that do not have sophisticated equipment. This method is based on LC separation and UV-Vis detection. During the sample preparation, the meat tissue was homogenized in acetonitrile at a ratio of 1:4 (tissue weight:acetonitrile volume). The homogenate was centrifuged, the supernatant was evaporated in a lyophilizator, and then the evaporation residue was dissolved in 20 µL of ethanol. For deproteinization, 15 µL of perchloric acid was added, and the sample prepared in this way was injected into a chromatographic column and analyzed using reversed-phased HPLC. The mobile phase consisted of 0.05 mol/L phosphate buffer pH 3.00 (component A) and acetonitrile (component B). UV detection was conducted at 245 nm. The experimentally determined LOQs were 0.25 µg/kg for azaperone and 0.12 µg/kg for azaperol. For both analytes, the calibration curves showed linearity in the tested concentration range from 50 to 300 µg/kg of tissue. The accuracy of the presented method did not exceed 15%, and the recovery was in the range of 85-115%. A validated analytical procedure was implemented for the analysis of various animal tissues for their content of azaperone and azaperol.

Analysis of 27 β-Blockers and Metabolites in Milk Powder by High Performance Liquid Chromatography Coupled to Quadrupole Orbitrap High-Resolution Mass Spectrometry

This paper presents an application of high performance liquid chromatography coupled with quadrupole orbitrap high-resolution mass spectrometry (HPLC-Q-Orbitrap HRMS) for the analysis of 27 β-blockers and metabolites in milk powder. Homogenized milk power samples were extracted by acetonitrile and purified by using Oasis PRiME HLB solid-phase extraction cartridges. The Ascentis^® C8 chromatographic column was used to separate the analytes. The quantification was achieved by using matrix-matched standard calibration curves with carazolol-d₇ and propranolol-d₇ as the internal standards. The results show an exceptional linear relationship with the concentrations of analytes over wide concentration ranges (0.5–500 μg kg⁻¹) as all the fitting coefficients of determination r² are > 0.995. All the limits of detection (LODs) and quantitation (LOQs) values were within the respective range of 0.2–1.5 μg kg⁻¹ and 0.5–5.0 μg kg⁻¹. Overall average recoveries were able to reach 66.1–100.4% with the intra- and inter-day variability under 10%. This method has been successfully applied to the screening of β-blockers and metabolites in commercial milk powders. At the same time, the corresponding characteristic fragmentation behavior of the 27 compounds was explored. The characteristic product ions were determined and applied to the actual samples screening.

Quantification of 16 β-lactams in chicken muscle by QuEChERS extraction and UPLC-Q-Orbitrap-MS with parallel reaction monitoring

A method is described for the analysis of 16 β-lactams in chicken muscle by UPLC-quadrupole(Q)-Orbitrap-MS with parallel reaction monitoring (PRM). QuEChERS approach includes clean-up step by sorbent of primary-secondary amine (PSA) and C18 was adopted for sample preparation. Q-Orbitrap with PRM showed high sensitivity with limits of detection (LODs) ranged from 0.01μgkg^-1 to 0.35μgkg^-1. The method was further validated by intra- and inter-day test with spiking levels less than MRLs (maximum residue limits, the European Union). Recovery (83-112%) and precision values (RSDs <15%) for all studied analytes were obtained. The result indicates that UPLC-Q-Orbitrap coupled with QuEChERS preparation can serve as a routine quantification method for β-lactam residues in chicken muscles.

Determination of 15 sedative residues in mutton by rapid resolution liquid chromatography-tandem mass spectrometry

BACKGROUND

The use of xenobiotic compounds in animal husbandry has given rise to consumer anxieties regarding residual risk and food safety. Thus, animal tissues have become main samples for residue analysis and food safety for sedatives. In this study, a rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) method was established for the determination of 15 sedatives residues in mutton.

RESULTS

After enzymolysis, sedatives residues in mutton were extracted by ammonium hydroxide-acetonitrile (10:90, v/v) and determined by RRLC-MS/MS with quantification by standard curve method. The calibration curves showed good linearity within the concentrations of 0.5-50 µg kg(-1) with the correlation coefficients (r(2)) ranged from 0.9639 to 0.9984. The limits of detection (LODs) and quantification (LOQs) were 0.25-2.5 and 0.5-5 µg kg(-1), respectively. The average recoveries of spikes samples were in the ranges of 74.1-116.8% with relative standard deviations of intra- and inter-day ranged from 2.6% to 11.2% and from 2.1% to 11.4%, respectively.

CONCLUSION

This method is simple, sensitive and accurate in the determination of sedative residues.

Simultaneous identification, confirmation and quantitation of illegal adulterated antidiabetics in herbal medicines and dietary supplements using high-resolution benchtop quadrupole-Orbitrap mass spectrometry

This paper presents an application of ultrahigh-performance liquid chromatography and quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HR MS) for the screening, confirmation and quantification of 11 antidiabetics in herbal medicines and dietary supplements. The mass spectrometer was operated in Full MS/dd-MS(2) (data-dependent MS(2)) mode. The full MS scan acquired data for identification and quantification, and dd-MS(2) scan obtained product ion spectra for confirmation. UHPLC-Q-Orbitrap MS quantification was achieved using matrix-matched standard calibration curves with phenacetin as internal standard. The method validation that included selectivity, sensitivity, calibration curve, accuracy and precision, recovery, matrix effect and stability was evaluated. The response showed good linear relationship with the concentrations of analytes over wide ranges (e.g., 0.0004-1 μg/g for metformin) with all the coefficients of correlation (r(2)) >0.9991. The detection limits (LODs) were in the range of 0.05-0.5 ng/g for different analytes. The recoveries yielded results higher than 74.3% for all compounds. The accuracy was in the range of -6.75 to 3.85%, while the intra- and inter-day precision ranged from 0.048 to 11.5%. Among 63 batches of herbal medicines and 34 batches of dietary supplements samples, 7 batches of dietary supplements were positive, while all the herbal medicines were negative. Overall, the novel UHPLC-Q-Orbitrap has demonstrated great performance for identification, confirmation and quantification of antidiabetics in herbal medicines and dietary supplements, ensuring food safety and public health.

Analyses and decreasing patterns of veterinary antianxiety medications in soils

An ultrasonic-assisted extraction method was developed to detect 16 antianxiety medications in soil samples using liquid chromatography-high resolution mass spectrometry (LC-HRMS), Orbitrap mass spectrometer. The determination method resulted in satisfactory sensitivity, linearity, recovery, repeatability, and within-laboratory reproducibility. Acepromazine, azaperone, and xylazine were incubated in control, amended, and sterilized soils. The amendment with powdered blood meal affected the relatively fast dissipations of acepromazine, azaperone, and xylazine in the soils. Dissipation kinetics of acepromazine were consistent with bi-phasic kinetics (first-order multi compartment) and the other couples were fit to single first-order kinetics. A hydroxylated acepromazine was identified from soil samples using Orbitrap mass spectrometry. According to sorption batch experiments, the adsorption of acepromazine and azaperone was greatly high, whereas that of xylazine was relatively low. Xylazine was persistent in the incubated soils, and acepromazine demonstrated fast initial dissipation; hence, xylazine could have a potential harmful effect on the environment. To the best of our knowledge, this is the first report on the dissipation and adsorption-desorption patters of animal pharmaceutical tranquilizers and α, β-blockers.

Uranyl-water-containing complexes: solid-state UV-MALDI mass spectrometric and IR spectroscopic approach for selective quantitation

Since primary environmental concept for long storage of nuclear waste involved assessment of water in uranium complexes depending on migration processes, the paper emphasized solid-state matrix-assisted laser desorption/ionization (MALDI) mass spectrometric (MS) and IR spectroscopic determination of UO2(NO3)2·6H2O; UO2(NO3)2·3H2O, α-, β-, and γ-UO3 modifications; UO3·xH2O (x = 1 or 2); UO3·H2O, described chemically as UO2(OH)2, β- and γ-UO2(OH)2 modifications; and UO4·2H2O, respectively. Advantages and limitation of vibrational spectroscopic approach are discussed, comparing optical spectroscopic data and crystallographic ones. Structural similarities occurred in α-γ modifications of UO3, and UO2(OH)2 compositions are analyzed. Selective speciation achieved by solid-state mass spectrometry is discussed both in terms of its analytical contribution for environmental quality assurance and assessment of radionuclides, and fundamental methodological interest related the mechanistic complex water exchange of UO3·H2O forms in the gas phase. In addition to high selectivity and precision, UV-MALDI-MS, employing an Orbitrap analyzer, was a method that provided fast steps that limited sample pretreatment techniques for direct analysis including imaging. Therefore, random and systematic errors altering metrology and originating from the sample pretreatment stages in the widely implemented analytical protocols for environmental sampling determination of actinides are significantly reduced involving the UV-MALDI-Orbitrap-MS method. The method of quantum chemistry is utilized as well to predict reliably the thermodynamics and nature of U-O bonds in uranium species in gas and condensed phases.

Solid-state UV-MALDI-MS assay of transition metal dithiocarbamate fungicides

The determination of transition metal containing dithiocarbamate fungicides represents a challenging aspect of analytical object. They have a low stability, low solubility and stabilize versatile coordination monomers, dimers, disulfides and/or S-oxidized derivatives. Their diverse biological activities and agricultural implementation encompass plant prevention and crop protection against a variety of plants containing fungi and diseases of 400 pathogens and 70 cultures. Nonetheless, those dithiocarbamates (DTCs) are banned for agricultural use in Europe or have expiration at years 2016-2017 because of their highly toxic degradation products and/or metabolites, in particular ethylene thiourea; they found large-scale implementations in materials research and medicine. Despite the broad interdisciplinary of DTC application, due to the above reasons, they have received little attention in the rapidly growing field of analytical chemistry, and in particular, the analytical mass spectrometry. Therefore, the study reported on qualitative, quantitative and structural analysis of ten DTCs (1-10), using the matrix assisted laser desorption/ionization (UV-MALDI)-Orbitrap-mass spectrometry (MS) contributed considerably to the implementation of the method for environmental and foodstuffs monitoring. Its ultrahigh resolving power and capacity for direct solid-state analysis, at limited number of sample pretreatment steps, at concentration levels of analytes of up to femtogram per gram resulted to achievement of a highly precise analytical information for these non-trivial objects. The presented fully validated method and technique is based on the successful ionization of DTCs embedded in three novel organic salts (M1-M3). In this regard, the reported MS and the single-crystal X-ray diffraction data as well as the quantum chemical one are able to correlate the molecular structures in condense and in the gas phase. Despite the novelty of the fundamental methodological character of the research reported, the promising metrology contributed to the applied aspect of the UV-MALDI-MS as a robust analytical method for environmental and foodstuffs monitoring, which is tested on two commercially available crop protecting products such as Mancozeb® and Antracol®, respectively.

Liquid chromatography tandem mass spectrometry in study of the pharmacokinetics of six steroidal saponins in rats

A rapid, simple and sensitive high-performance liquid chromatography tandem mass spectrometry method was developed and validated for simultaneous determination of six main steroidal saponins in Paris polyphylla in rat plasma. Ginsenoside Rg3 was selected as the internal standard (IS). Plasma samples were pretreated with protein precipitation, and the separation was achieved on a reverse phase Agilent poroshell120 EC-C18 column using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid. The triple quadruple mass spectrometer was set in negative electrospray ionization mode and multiple reaction monitoring (MRM) was used for six steroidal saponins quantification. The precursors to produce ion transitions monitored for polyphyllin I, polyphyllin II, polyphyllin VI, polyphyllin VII, dioscin, gracillin and IS were m/z 899.5>853.4, 1059.5>1013.5, 783.4>737.4, 1075.5>1029.5, 913.5>867.4, 929.5>883.4 and 819.5>783.4, respectively. The intra- and inter-day precisions (RSD%) were less than 13% and the average extraction recoveries ranged from 85% to 97.0% for each analyte. Six steroidal saponins were proved to be stable during sample storage, preparation and analytical procedures. The established method was employed for simultaneous quantification and successfully used for the first time for the pharmacokinetics evaluation of the six main compounds after intragastric administration of P. polyphylla extract in Sprague-Dawley rats.

Separation and characterization of sucrose esters from Oriental tobacco leaves using accelerated solvent extraction followed by SPE coupled to HPLC with ion-trap MS detection

Sucrose esters (SEs) were successfully extracted from Oriental tobacco leaves using a new methodology based on accelerated solvent extraction followed by hydrophilic-lipophilic balanced cartridge cleanup step. The SEs were detected by HPLC with ion-trap MS detection using an electrospray interface operated in the positive ion mode. This methodology combines the high efficiency of extraction provided by a pressurized fluid and the highly sensitive characterization offered by ion-trap MS. Under the optimized conditions, 14 SEs were first identified among a total of 23 SEs found in Oriental tobacco leaves. Under the same conditions, only four new SEs were extracted by using traditional ultrasound-assisted extraction and liquid-solid extraction methods. The present method might be potentially useful in high-efficiency extraction and sensitive characterization of SEs from complex matrices such as tobacco leaves.

A novel UV-MALDI-MS analytical approach for determination of halogenated phenyl-containing pesticides

The paper highlighted the capability of the UV-MALDI mass spectrometry, employing the Orbitrap analyzer for solid-state assay of halogenated phenyl-pesticides in mixtures. It is successfully applied for the analysis of eighteen (1)-(18) molecular objects of Fenarimol (1) type and their condensation products (P5)-(P12). The full method and technique validation is performed using the dried droplet sample preparation technique on embedded analytes in novel organic matrix crystals of N-(1H-benzoimidazol-2-yl)-guanidine (M4) and (E)-phenyl-2-pyridyl ketone oxime (M5), resulting to successful ionization of the analytes. Since the sampling technique in the UV-MALDI method is a key step in the overall process impacting significantly the metrology through the reproducibility of the data, the crystallization of M4, M5 and matrix-analyte in situ morphology of the samples is controlled by single crystal X-ray diffraction. The achieved promising metrology of LODs, of 0.46ngkg(-1) (1.53ngkg(-1) LOQs), is several orders of magnitude lower than the reported ecotoxicological effect values of studied pesticides. It is confirmed by the partial validated protocol based on ESI-MS. Inasmuch that LC-MS/MS is a method of choice for foodstuffs monitoring of organic contaminations, due to its routine quantitative analytical procedures, it is often characterized with the difficulties of the chromatographic separation of the closely structured analytes at a large scale of experimental conditions, complex multi-step sampling pretreatments, which inevitably alert the variables through the systematic and random errors. In this respect, notwithstanding the complex quantitative UV-MALDI-Orbitrap-MS procedure, conceptually different from the LC-MS/MS one, its high resolving power, capability for achieving meaningful analytical qualitative, quantitative and structural information of low-molecular weight analytes, its instrumental and sampling operation flexibility, applicable for a large scale of foodstuff matrices, and operating at the analyte concentrations of up to fgg(-1) make UV-MALDI-Orbitrap-MS a perspective method of choice for an extensive implementation in the foodstuffs monitoring practice for control of the most essential task related to the assessment of the human health risks from environmental and foodstuff contaminations.