High-performance liquid chromatographic, capillary electrophoretic and capillary electrophoretic-electrospray ionisation mass spectrometric analysis of selected alkaloid groups

Dynamics of the Aspiration of Charged Droplets into a LC-ESI-MS System

Electrospray ionization (ESI) enables coupling between liquid chromatography (LC) and mass spectrometry (MS). Since it is a gentle ionization method, it is frequently used for the analysis of large biomolecules. In recent years, several experimental setups have demonstrated that the use of ESI results in the formation of charged droplets that are aspirated into the vacuum systems of mass spectrometers. This results in a variety of consequences, such as instrument contamination, which can impede the analytical performance. We investigate the signatures of aspirated charged droplets with a commercial LC-ESI-MS system at analytical conditions. Previous observations without LC coupling are reproduced and show that significant droplet aspiration is probably taking place at analytical LC-ESI-MS conditions. This common phenomenon likely decreases the instrument sensitivity. Analyte can be released by isolation and fragmentation of droplet fragments; thus, aspirated droplets can mask analyte even in the mass analyzer region. The complex morphology of droplet MS/MS mass spectra is highly reproducible at the same experimental conditions. This implies the existence of distinct molecular reaction pathways of the droplet fragments. To assess the effect of droplet aspiration on analytical applications, relevant method and ion source parameters, which are commonly varied during method optimization, were investigated. Further variations of the solvent composition revealed that the aspirated droplets and their fragmentation are particularly sensitive to the solvent composition and thus also to the LC solvent gradient in an analytical experiment.

Optimized HPLC extraction method of quercetin and berberine based on response surface analysis

In order to establish a method for simultaneous determination and extraction of quercetin and berberine in soil, HPLC-PDA multi-wavelength method was used to detect the content of berberine and quercetin in soil solution. The detection wavelength was 210 nm and 347 nm. The column temperature was 30 °C, the mobile phase A was acetonitrile, the mobile phase B was 0.1% phosphoric acid aqueous solution, and the flow rate was 1.0 mL min-1. Under the condition of isocratic elution, quercetin and berberine were completely separated within 20 min. The detection limit concentration of quercetin was 0.078 mg L-1, and the detection limit of berberine was 0.019 mg L-1. Both of them reached the trace level, and the recovery rate was between 97.2% and 107.4%. The response surface method was used to optimize the ultrasonic extraction method. The three main factors of extraction concentration, extraction temperature and solid-liquid ratio were optimized to obtain the highest extraction efficiency. The optimum extraction efficiency was as follows: 1 g soil sample was extracted with 80% ethanol aqueous solution, ultrasonic time was 10 min, ultrasonic temperature was 44 °C, and solid-liquid ratio was 1 : 17 g mL-1. The extracted quercetin and berberine concentrations were close to the predicted values of response surface optimization. The method of extracting and determining berberine and quercetin from soil established in this experiment is simple, fast, low cost and high safety. The feedback of the results also further verifies the feasibility in practical production and application, and provides reference value for further research and analysis of different allelochemicals in soil.

Evaluation of vinburnine in pharmaceuticals by smart spectrophotometric methods; full stability study

Vinburnine (VNB) is a vinca alkaloid used as a vasodilator to enhance cerebral circulatory insufficiency. It is a cyclic amide containing drug which is expected to be sensitive to hydrolytic degradation. The degradation profile of VNB was studied in this work following ICH recommendations for stability study. The drug was sensitive only to degradation with NaOH with the formation of the carboxylic acid derivative, identified by IR and ¹H NMR analyses as 2-((1S,12bS)-1-ethyl-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a] quinolizin-1-yl) acetic acid, (DEG). In this study five simple, smart and univariate stability indicating spectrophotometric methods were developed and validated for simultaneous determination of VNB and DEG for the first time. The developed methods include; Dual Wavelength Method (DWM), Dual Wavelength Resolution Method (DWRM), Factorized Absorbance Difference Method (FADM), Advanced Absorbance Subtraction Method (AASM), and Derivative Amplitude Factor Method (DAFM). These methods were capable of determination of VNB and DEG over the ranges of 1-30 and 3-50 µg/mL, respectively. The proposed methods were simple, smart, specific, and could be applied for analyzing synthetic mixtures of VNB and DEG and were successfully applied for determination of the drug in commercially available capsules. The obtained results of these methods were statistically compared with the reported HPLC one using student's-t and F- tests, where no significant difference was observed. Validation of the developed methods was applied according to ICH recommendations and all the results were within the acceptable limits.

Solid-Contact Potentiometric Sensors Based on Main-Tailored Bio-Mimics for Trace Detection of Harmine Hallucinogen in Urine Specimens

All-solid-state potentiometric sensors have attracted great attention over other types of potentiometric sensors due to their outstanding properties such as enhanced portability, simplicity of handling, affordability and flexibility. Herein, a novel solid-contact ion-selective electrode (SC-ISE) based on poly(3,4-ethylenedioxythiophene) (PEDOT) as the ion-to-electron transducer was designed and characterized for rapid detection of harmine. The harmine-sensing membrane was based on the use of synthesized imprinted bio-mimics as a selective material for this recognition. The imprinted receptors were synthesized using acrylamide (AA) and ethylene glycol dimethacrylate (EGDMA) as functional monomer and cross-linker, respectively. The polymerization process was carried out at 70 °C in the presence of dibenzoyl peroxide (DBO) as an initiator. The sensing membrane in addition to the solid-contact layer was applied to a glassy-carbon disc as an electronic conductor. All performance characteristics of the presented electrode in terms of linearity, detection limit, pH range, response time and selectivity were evaluated. The sensor revealed a wide linearity over the range 2.0 × 10⁻⁷–1.0 × 10⁻² M, with a detection limit of 0.02 µg/mL and a sensitivity slope of 59.2 ± 0.8 mV/hamine concentration decade. A 40 mM Britton–Robinson (BR) buffer solution at pH of 6 was used for all harmine measurements. The electrode showed good selectivity towards harmine over other common interfering ions, and maintained a stable electrochemical response over two weeks. After applying the validation requirements, the proposed method revealed good performance characteristics. Method precision, accuracy, bias, trueness, repeatability, reproducibility, and uncertainty were also evaluated. These analytical capabilities support the fast and direct assessment of harmine in different urine specimens. The analytical results were compared with the standard liquid chromatographic method. The results obtained demonstrated that PEDOT/PSS was a promising solid-contact ion-to-electron transducer material in the development of harmine-ISE. The electrodes manifested enhanced stability and low cost, which provides a wide number of potential applications for pharmaceutical and forensic analysis.

Determination and Quantification of the Vinblastine Content in Purple, Red, and White Catharanthus Roseus Leaves Using RP-HPLC Method

Purpose: To determine and quantify vinblastine in different varieties of Catharanthus roseus using reversed-phase HPLC method.

Methods: The liquid chromatographic separation was performed using a reversed phase C18, Microsorb - MV column (250 mm x 4.6 mm, 5 µm) at room temperature and eluted with a mobile phase containing methanol – phosphate buffer (5 mM, pH 6.0) – acetonitrile with different proportion gradient elution at a flow rate of 2.0 mL min^-1 and detection at 254 nm.

Results: The HPLC method was utilized for the quantification of vinblastine in purple, red and white varieties of Catharanthus roseus leaves. The separation was achieved in less than 8 min. The peak confirmation was done based on the retention times and UV spectra of the reference substance. The method was validated with respect to linearity, precision, recovery, limit of detection and quantification. Results showed that the purple variety gives 1.2 and 1.5 times more vinblastine concentration compared to the white and pink varieties, respectively.

Conclusion: The obtained results from different varieties are thus useful for the purpose of vinblastine production from Catharanthus roseus plant.

Capillary electrophoresis study on the base-catalyzed formation of bioactive oxidized metabolites of 20-hydroxyecdysone

A novel capillary electrophoretic method was developed for the analysis and monitoring of the base-catalyzed autoxidation of 20-hydroxyecdysone, a worldwide used non-hormonal anabolic food supplement. An effective separation of the starting material and its bioactive oxidized derivatives was achieved by using sulfobutyl-β-cyclodextrin as selector at pH 11 and by fixing the separation voltage at +30kV. Only a dilution step was inserted before injecting the sample, taken from the crude reaction mixture, to the capillary electrophoresis instrument. The same alkaline pH was used for the analysis as for the reaction, unlike the previously reported HPLC study where sample neutralization was required prior to the measurement. Due to the very short analysis time (6min) in capillary electrophoresis, more frequent sampling and more detailed time scale analysis could be carried out. Furthermore, in contrast with the preceding HPLC results, the previously unobserved calonysterone could also be detected by capillary electrophoresis as a minor primary product. Our novel method demonstrated higher resolution than the one before. Baseline separation could be achieved and the resolution values were in the range of 1.9-7.0. The limit of detection was below 71μg/ml, the relative standard deviation values of the migration time and peak area for intra- and inter-day precision were less than 10%. The more precise, direct monitoring of the time dependency of the oxidation process is expected to have a significant impact on yield optimization initiatives to allow related pharmacological studies in the near future.

Parts-per-trillion detection of harmala alkaloids in Undaria pinnatifida algae by on-line solid phase extraction capillary electrophoresis mass spectrometry

β-carboline alkaloids of the harmala group (HAlks)-a family of compounds with pharmacologic effects-can be found at trace levels (<25 μg kg-1 algae) in the edible invasive algae Undaria pinnatifida, known commonly as wakame. In this study, we present a simple and sensitive method to detect and quantify at low parts-per-trillion levels the six HAlks more frequently found in those plants. The method is based on on-line solid phase extraction capillary electrophoresis mass spectrometry using a C18 sorbent. First, the methodology was optimized and validated with standard solutions through the use of ultraviolet (UV) and mass spectrometry (MS) detection. Second, the optimized method for MS detection was applied to an analysis of the HAlks in U. pinnatifida extracts. The method achieved limits of detection between 2 and 77 pg mL-1 for standards, producing an analyte preconcentration of about 1000-times in comparison to CE-MS. Some matrix effects were observed for the complex wakame extracts, especially for the most polar HAlks (harmol and harmalol), which bear aromatic hydroxyl groups. Harmine, harmaline, and norharmane were not detected in the algal extracts, whereas harmane was found at 70 pg mL-1 (70 ng kg-1 dry algae). The results underscored that C18-SPE-CE-MS may be considered as a powerful method to detect trace levels of alkaloids and other bioactive small molecules in complex plant extracts.

A rapid and simple method for the determination of psychoactive alkaloids by CE-UV: application to Peganum Harmala seed infusions

The β-carboline alkaloids of the harmala (HAlks) group are compounds widely spread in many natural sources, but found at relatively high levels in some specific plants like Peganum harmala (Syrian rue) or Banisteriopsis caapi. HAlks are a reversible Mono Amino Oxidase type A Inhibitor (MAOI) and, as a consequence, these plants or their extracts can be used to produce psychotropic effects when are combined with psychotropic drugs based on amino groups. Since the occurrence and the levels of the HAlks in natural sources are subject to significant variability, more widespread use is not clinical but recreational or ritual, for example B. caapi is a known part of the Ayahuasca ritual mixture. The lack of simple methods to control the variable levels of these compounds in natural sources restricts the possibilities to dose in strict quantities and, as a consequence, limits its use with pharmacological or clinical purposes. In this work, we present a fast, simple, and robust method of quantifying simultaneously the six HAlks more frequently found in plants, i.e., harmine, harmaline, harmol, harmalol, harmane, and norharmane, by capillary electrophoresis instruments equipped with the more common detector UV. The method is applied to analyze these HAlks in P. Harmala seeds infusion which is a frequent intake form for these HAlks. The method is validated in three different instruments in order to evaluate the transferability and to compare the performances between them. In this case, harmaline, harmine, and harmol were found in the infusion samples. Copyright © 2016 John Wiley & Sons, Ltd.

Analysis of Indole Alkaloids from Rhazya stricta Hairy Roots by Ultra-Performance Liquid Chromatography-Mass Spectrometry

Rhazya stricta Decne. (Apocynaceae) contains a large number of terpenoid indole alkaloids (TIAs). This study focused on the composition of alkaloids obtained from transformed hairy root cultures of R. stricta employing ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). In the UPLC-MS analyses, a total of 20 TIAs were identified from crude extracts. Eburenine and vincanine were the main alkaloids followed by polar glucoalkaloids, strictosidine lactam and strictosidine. Secodine-type alkaloids, tetrahydrosecodinol, tetrahydro- and dihydrosecodine were detected too. The occurrence of tetrahydrosecodinol was confirmed for the first time for R. stricta. Furthermore, two isomers of yohimbine, serpentine and vallesiachotamine were identified. The study shows that a characteristic pattern of biosynthetically related TIAs can be monitored in Rhazya hairy root crude extract by this chromatographic method.

Separation and purification of two new and two known alkaloids from leaves of Nitraria sibirica by pH-zone-refining counter-current chromatography

The total alkaloids from Nitraria sibirica leaves have been confirmed to exhibit significant protective effects against inflammatory renal injury, hypertension and albuminuria in angiotensin II-salt hypertension. In the present study, a separation method of pH-zone-refining counter-current chromatography was established for separation of the alkaloids from N. sibirica. The separation was performed with a solvent system of MtBE-n-BuOH-H2O (2:2:5, v/v) at a flow rate of 2.0mL/min. And 15mM triethylamine (TEA) was added to the upper organic phase, while 10mM hydrochloric acid was added to the lower aqueous phase. As a result, a new alkaloid, schobemine (5.6mg), and a known alkaloid, nitraramine (5.0mg), together with fractions A and B were obtained from the total alkaloids of N. sibirica. The fractions A and B were further purified by means of pH-zone-refining counter-current chromatography with solvent systems of n-hexane-n-BuOH-H2O (1.5:3.5:5, v/v) and (2:3:5, v/v), respectively. TEA (10mM) was added to the upper phase, and 10mM of HCl was added to the lower phase in above two solvent systems, respectively. As a result, a known alkaloid, schoberidine (5.0mg), and a new alkaloid, schoberimine (3.0mg) were obtained from fractions A and B, respectively. The purities of the compounds were measured by HPLC-ELSD, and their structures were identified by ESI-MS, 1D and 2D NMR.

Fast determination of harmala alkaloids in edible algae by capillary electrophoresis mass spectrometry

The use of algae as a foodstuff is rapidly expanding worldwide from the East Asian countries, where they are also used for medical care. Harmala alkaloids (HAlk) are a family of bioactive compounds found in the extracts of some plants, including wakame (Undaria pinnatifida), an edible marine invasive algae. HAlks are based on a characteristic β-carboline structure with at least one amino ionizable group. In this work, we report the successful separation of a mixture of six HAlks (harmine, harmaline, harmol, harmalol, harmane, and norharmane) by capillary electrophoresis ion-trap mass spectrometry (CE-IT-MS) in less than 8 min. Optimum separation in fused-silica capillaries and detection sensitivity in positive-ion mode were achieved using a background electrolyte (BGE) with 25 mmol L(-1) ammonium acetate (pH 7.8) and 10% (v/v) methanol, and a sheath liquid with 60:40 (v/v) isopropanol-water and 0.05% (v/v) formic acid. The separation method was validated in terms of linearity, limits of detection and quantification, repeatability, and reproducibility. Later, a sample pretreatment was carefully optimized to determine HAlks in commercial wakame samples with excellent recovery and repeatability. For the complex wakame extracts, the MS-MS fragmentation patterns of the different HAlks were useful to ensure a reliable identification. The complete procedure was validated using the standard-addition calibration method, determining matrix effects on the studied compounds. Harmalol, harmine, and harmaline were naturally present in the samples and were quantified at very low concentrations, ranging from 7 to 24 μg kg(-1) dry algae.

Differential detection of Rhizoma coptidis by capillary electrophoresis electrospray ionization mass spectrometry with a nanospray interface

A lab prototype CE-nanospray-MS platform with a high sensitivity porous sprayer was successfully applied in differential identification of Rhizoma coptidis in this paper. To obtain a stable and reliable nanospray, detailed optimizations about emitter geometry, buffer composition, emitter position, and spray voltage, as well as emitter cleanliness were discussed. Results showed that the reproducibility and sensitivity for separations of alkaloid standards were satisfactory using CE-nanospray-MS, which were also compared to ultra-HPLC (UHPLC)-MS. Their signal responds were at the same order of magnitude (intensities: 0.8 - 1.5 × 10(8) vs. 3.8 - 6.2 × 10(8) ), even though a 2 nL injection for CE was 2500-fold lower than UHPLC (5 μL injection). The absolute LOD results of CE-MS showed a remarkable superiority (18-24 fg), equal to 1000-fold lower than that of UHPLC-MS. Principal component analysis (PCA) of adulterated R. coptidis showed that this protocol had the ability to profile and qualify complex herb medicines, which also created a great potential for evaluation and qualification of rare and valuable Chinese medicines in future.

A sensitive and selective liquid chromatography-tandem mass spectrometry method for simultaneous determination of five isoquinoline alkaloids from Chelidonium majus L. in rat plasma and its application to a pharmacokinetic study

Chelidonium majus L. is one of the most important medicinal plants of the family Papaveraceae. Its pharmacological effects have been primarily attributed to the presence of a number of alkaloids. In the present study, a sensitive and selective liquid chromatography-tandem mass spectrometry method for simultaneous determination of five isoquinoline alkaloids from Chelidonium majus L. was developed and validated. The analytes (protopine, chelidonine, coptisine, sanguinarine and chelerythrine), together with the internal standard (palmatine), were extracted from acidified rat plasma with ethyl acetate-dichloromethane (4:1, v/v). Chromatographic separation was carried out on a Diamonsil C(18) column with an isocratic mobile phase consisting of acetonitrile and water (adjusted to pH 2.3 with formic acid) (30:70, v/v) at a flow rate of 0.4 ml/min. Mass spectrometric detection was performed by selected reaction monitoring mode via electrospray ionization source operating in positive ionization mode. The assay exhibited good linearity (r ≥ 0.9933) for all the analytes. The lower limits of quantification were 0.197-1.27 ng/ml using only 50 µl of plasma sample. The intra- and inter-day precisions were less than 11.9%, and the accuracy was between -6.3% and 9.3%. The method was successfully applied to the pharmacokinetic study of the five alkaloids in rats after intragastric administration of Chelidonium majus L. extract.

Nonaqueous capillary electrophoresis-mass spectrometry: a versatile, straightforward tool for the analysis of alkaloids from psychoactive plant extracts

In this study we show that a nonaqueous capillary electrophoresis mass spectrometry (NACE-MS) method carefully optimized by a design of experiment can be applied to a very large number of alkaloids in different plant extracts. It is possible to characterize the pattern of the psychoactive alkaloids in several plant samples and preparations thereof, each presenting different challenges in their analysis. The method is shown to be able to separate structurally closely related substances, diastereomers and further isobaric compounds, to separate members of different alkaloid classes within one run and to tolerate significant matrix load. A comparison with methods presented in the literature reveals that a near-generic NACE-MS method for the fast profiling of alkaloids in forensically relevant plant samples has been developed.

Mass spectrometry-based microbial metabolomics

Through the characterization of metabolic pathways, metabolomics is able to illuminate the activities of a cell at the functional level. However, the metabolome, which is comprised of hundreds of chemically diverse metabolites, is rather difficult to monitor. Mass spectrometry (MS)-based profiling methods are increasingly being utilized for this purpose. To this end, MS is often coupled to the separation techniques gas chromatography (GC), liquid chromatography (LC), and capillary electrophoresis (CE). The mass-based selectivity that the MS provides, together with the chromatographic or electrophoretic separation of analytes, creates hyphenated techniques that are ideally suited to the measurement of large numbers of metabolites from microbial extracts. In this chapter, we describe GC-MS, LC-MS, and CE-MS methods that are applicable to microbial metabolomics experiments.

Medicinal halophytes: potent source of health promoting biomolecules with medical, nutraceutical and food applications

Salt-tolerant plants grow in a wide variety of saline habitats, from coastal regions, salt marshes and mudflats to inland deserts, salt flats and steppes. Halophytes living in these extreme environments have to deal with frequent changes in salinity level. This can be done by developing adaptive responses including the synthesis of several bioactive molecules. Consequently, several salt marsh plants have traditionally been used for medical, nutritional, and even artisanal purposes. Currently, an increasing interest is granted to these species because of their high content in bioactive compounds (primary and secondary metabolites) such as polyunsaturated fatty acids, carotenoids, vitamins, sterols, essential oils (terpenes), polysaccharides, glycosides, and phenolic compounds. These bioactive substances display potent antioxidant, antimicrobial, anti-inflammatory, and anti-tumoral activities, and therefore represent key-compounds in preventing various diseases (e.g. cancer, chronic inflammation, atherosclerosis and cardiovascular disorder) and ageing processes. The ongoing research will lead to the utilisation of halophytes as a new source of healthy products as functional foods, nutraceuticals or active principles in several industries. This contribution focuses on the ethnopharmacological uses of halophytes in traditional medicine and reviews recent investigations on their biological activities and nutraceuticals. The work is distributed according to the different families of nutraceuticals (lipids, vitamins, proteins, glycosides, phenolic compounds, etc.) discussing the analytical techniques employed for their determination. Information about the claimed health promoting effects of the different families of nutraceuticals is also provided together with data on their application.

Separation of alkaloids from herbs using high-speed counter-current chromatography

Alkaloids represent a most widespread group of bioactive natural products. Because of their alkalinity and structural diversity, the fractionation and purification of the alkaloids from herbs can often present a number of practical difficulties using the conventional chromatographic techniques. High-speed counter-current chromatography (HSCCC) is a liquid-liquid partition chromatography with a support-free liquid stationary phase, and is gaining more and more popularity as a viable separation technique for bioactive compounds from natural resources. In the present review, focus is placed on the separation of alkaloids by both conventional HSCCC and pH-zone-refining counter-current chromatography (CCC) techniques from herbs. The review presents the separation of over 120 different alkaloid compounds from more than 30 plant species by the conventional HSCCC and pH-zone-refining CCC. Based on the data from the literature, the proper solvent systems for the separation of alkaloids by the conventional HSCCC and pH-zone-refining CCC are also summarized.

Qualitative and quantitative analysis in quality control of traditional Chinese medicines

Separation techniques with high efficiency and sensitive detection have been widely used for quality control of traditional Chinese medicines (TCMs). High-performance liquid chromatography, gas chromatography, and capillary electrophoresis are commonly used to separate various components in TCMs. Ultraviolet detection, fluorescence detection, evaporative light-scattering detection, mass spectrometry and nuclear magnetic resonance can be applied to separation techniques for qualitative and quantitative analysis of TCMs. The development of quality control for TCMs based on quantitative and qualitative analysis from 2000 to 2007 are reviewed; the fingerprint technique is also discussed due to its broad application in the quality control of TCMs. Prospects for further research based on our primary results are also discussed.

Recent advances in the application of capillary electrophoresis with mass spectrometric detection

This review gives an overview of applications of CE coupled to MS detection published in the literature of the last three years. The works discussed in this paper comprise a wide range of different fields of application. These include important sections such as the analysis of biomolecules, the analysis of pharmaceuticals and their metabolites in different matrices, environmental analysis, and also investigations on the composition of technical products.

Recent applications of capillary electrophoresis-electrospray ionisation-mass spectrometry in drug analysis

A critical review of applications for the period 2000-2004, taken from the Web of Knowledge database, of the technique capillary electrophoresis-electrospray ionisation-mass spectrometry (CE-ESI-MS) in drug analysis is presented. The review is concerned with molecules of mass less than 500 Da, chosen according to selected structural classes in which they give ESI signals primarily as [M+H](+) ions although other ions, such as [M-H](-), [M+Na](+), and [M+NH(4)](+), are also reported. These structural classes are drugs with amine-containing side chains, drugs with N-containing saturated ring structures, 1,4-benzodiazepines, other heterocyclic hypnotics, carbohydrates, sulphonylureas, anthracyclines, sulphonamides, penicillins, cephalosporins, tetracyclines, nitrocatechols, steroids, flavonoids/polyphenols, cannabinols, and miscellaneous molecules. Details are given on the fragmentations, where available, that these ionic species exhibit in-source and in ion-trap, triple quadrupole, and time of flight-mass spectrometers. The review gives a critical evaluation of these recent CE-ESI-MS analytical methods in drug analysis. Analytical information on, for example, sample concentration techniques, CE separation conditions, recoveries from biological media and limits of detection (LODs) are provided. Potential applications of CE-MS to particular drugs or drug classes are also briefly discussed in the text.

Capillary electrophoresis-mass spectrometry in food analysis

This work provides an updated overview (including works published till June 2004) on the principal applications of capillary electrophoresis-mass spectrometry (CE-MS) together with their main advantages and drawbacks in food science. Thus, analysis of amino acids, peptides, proteins, carbohydrates, or polyphenols by CE-MS in different foods is reviewed. Also, other natural compounds (e.g., alkaloids) and toxins analyzed by CE-MS in foods are revised. Moreover, exogenous substances with a potential risk for human health (e.g., pesticides, drugs) detected in foods by CE-MS are included in this work. The usefulness of CE-MS for food analysis and the information that this coupling can provide in terms of processing, composition, authenticity, quality, or safety of foods is also discussed.

Insecticidal compounds of the biofilm-forming cyanobacterium Fischerella sp. (ATCC 43239)

Cyanobacterial biofilms are grazed by many different benthic invertebrates. In particular, larvae of insects are often present in great numbers and exert strong grazing pressure on cyanobacteria. Along with morphological adaptations, allelochemicals may have been developed as defense mechanisms against insect larvae. To investigate the chemical defense of biofilm-forming cyanobacteria, larvae of Chironomus sp., a widely distributed genus in this habitat, were used. Ten artificial biofilms of axenic and nonaxenic cyanobacteria were screened for insecticidal activity against Chironomus sp. Fischerella 43239 was the cyanobacterium that exhibited the highest acute toxicity. A bioassay-guided isolation procedure was used to study the compounds responsible for toxicity in more detail. A toxic fraction was obtained when the 60% methanolic extract of Fischerella 43239 was separated on a C18 HPLC column. Electrospray mass spectrometry indicated the presence of several compounds in this fraction. The successful separation into individual compounds was achieved by HPLC on a cyanopropyl column. The heavily clustered quasimolecular ions observed on an electrospray mass spectrometer and the absorption spectra of the separated compounds were indicative of indole derivatives. The existence in the benthic cyanobacterium Fischerella 43239 of strong insecticidal metabolites that serve as chemical protection agents against insect larvae is supported by the data.

Separation Methods for Toxic Components in Traditional Chinese Medicines

Traditional Chinese medicines (TCMs) with many unique functions for treating diseases have attracted the interest of people worldwide. They have been popularly utilized for therapy and health promotion in most Asian countries and even in many European and North American countries. However, it should be clearly noted that TCMs are mixtures with complicated composition usually containing hundreds, even thousands of chemically different constituents, and it is the multiple constituents that work synthetically to determine the ultimate effect of a formula of TCM. Meanwhile, some components with toxicity in some TCMs, having various negative effects on different parts of body, may do serious harm to people's health; such harm in particular requires our attention. In this article, applications of different chromatographic and electrophoretic techniques in the analysis of toxic components in TCMs in recent decades have been comprehensively reviewed and some hyphenated procedures (combinations of two kinds of measurement) applied in this field are also summarized.

Recent advances in analysis of Chinese medical plants and traditional medicines

Chinese herbal medicine is gaining increasing popularity worldwide for health promotion and adjuvant therapy. Thus, selective and efficient analytical methods are required not only for quality assurance but also for authentication of the plant material. Applications of both chromatographic and electrophoretic techniques to the analysis of medicinal plants and Chinese traditional medicine preparations over the last 3 years are outlined in this review. The role of chemical fingerprinting is highlighted and a brief survey of determination of toxic components, natural and synthetic adulterants is also included. Moreover, different sample pretreatment and extraction methods are discussed.

Analysis of Chinese medicine preparations by capillary electrophoresis–mass spectrometry

In Chinese medicines, herbs are usually prepared before use by patients. Since the preparation procedures convert the original component into one or more products, study of the procedures is usually complex and involves several compounds. On-line coupling of capillary electrophoresis (CE) to mass spectrometry (MS) allows both the efficient separation of CE and the specific and sensitive detection of MS to be achieved. In this study, CE-MS was applied to the determination of alkaloids in Maqianzi (the seed of Strychnos pierrian) and Wutou (aconite root, Radix aconiti praeparata) during the preparation procedure. With optimal CE-MS conditions, alkaloids in both prepared and unprepared Maqianzi were determined successfully in the total ion current (TIC) mode. However, single ion monitoring (SIM) had to be applied for the separation of aconitum alkaloids and their hydrolysis products. Quantification data indicated that MS detection under SIM mode is more sensitive than UV detection. Based on the CE-MS method developed, the hydrolysis of aconitum alkaloids in water and methanol was also studied.