Using bamboo charcoal as solid-phase extraction adsorbent for the ultratrace-level determination of perfluorooctanoic acid in water samples by high-performance liquid chromatography–mass spectrometry

In recent years, bamboo charcoal, a new kind of material with special microporous and biological characteristics, has attracted great attention in many application fields. In this paper, the potential of bamboo charcoal to act as a solid-phase extraction (SPE) adsorbent for the enrichment of the environmental pollutant perfluorooctanoic acid, which is one of the newest types of persistent organic pollutants in the environment, has been investigated. Important factors that may influence the enrichment efficiency—such as the eluent and its volume, the flow rate of the sample, the pH of the sample and the sample volume—were investigated and optimized in detail. Under the optimum conditions, the limit of detection for PFOA was 0.2 ng L⁻¹. The experimental results indicated that this approach gives good linearity (R ² = 0.9995) over the range 1–1000 ng L⁻¹ and good reproducibility, with a relative standard deviation of 4.0% (n = 5). The proposed method has been applied to the analysis of real water samples, and satisfactory results were obtained. The average spiked recoveries were in the range 79.5∼118.3 %. All of the results indicate that the proposed method could be used for the determination of PFOA at ultratrace levels in water samples.     

A review of recent advances in electrochemically modulated extraction methods

The use of electrochemistry and electrical behavior as a control and manipulation factor in analyte extractions is reviewed. Electromodulated extractions of ionic and neutral analytes are possible using this general approach. Extractions based on solid–liquid, liquid–liquid and membrane behaviors have been demonstrated and reported together with analyte extractions from real matrices and interfacing with instrumental detection methods. The electromodulation strategy offers great opportunities for selectivity in sample preparation.     

Isolation and Determination of Sterols in Rapeseed Oil by HPLC-MS

This article has been retracted     

Effects of sample pretreatment and storage conditions in the determination of pyrethroids in water samples by solid-phase microextraction and gas chromatography–mass spectrometry

The aqueous instability of pyrethroids and other compounds usually found in commercial pesticide formulations has been demonstrated in this work. Several types of sample treatment have been studied to avoid analyte losses during sample manipulation and storage. Analysis was performed by SPME–GC–MS. Addition of sodium thiosulfate to tap water prevented pyrethroid degradation as a result of oxidation by free chlorine. The amount added was optimized to minimize the effect of the salt on the analytical results. Analysis of samples that had been stored at 4 °C for several days revealed loss of some of the pyrethroids in the first period of storage. The effect of freezing the samples was studied and it was confirmed that samples could be stabilized for at least one week by freezing. Finally, addition of a miscible organic solvent, for example acetone, led to improvement of the analytical precision. The quality of the SPME–GC–MS method was studied. Linearity (R > 0.993), repeatability (RSD < 15%), and sensitivity (detection limits between 0.9 and 35 pg mL⁻¹) were good. When the procedure was applied to real samples including run off and waste water some of the target compounds were identified and quantified.      

High-performance liquid chromatography–tandem mass spectrometry in the identification and determination of phase I and phase II drug metabolites

Applications of tandem mass spectrometry (MS/MS) techniques coupled with high-performance liquid chromatography (HPLC) in the identification and determination of phase I and phase II drug metabolites are reviewed with an emphasis on recent papers published predominantly within the last 6 years (2002–2007) reporting the employment of atmospheric pressure ionization techniques as the most promising approach for a sensitive detection, positive identification and quantitation of metabolites in complex biological matrices. This review is devoted to in vitro and in vivo drug biotransformation in humans and animals. The first step preceding an HPLC-MS bioanalysis consists in the choice of suitable sample preparation procedures (biomatrix sampling, homogenization, internal standard addition, deproteination, centrifugation, extraction). The subsequent step is the right optimization of chromatographic conditions providing the required separation selectivity, analysis time and also good compatibility with the MS detection. This is usually not accessible without the employment of the parent drug and synthesized or isolated chemical standards of expected phase I and sometimes also phase II metabolites. The incorporation of additional detectors (photodiode-array UV, fluorescence, polarimetric and others) between the HPLC and MS instruments can result in valuable analytical information supplementing MS results. The relation among the structural changes caused by metabolic reactions and corresponding shifts in the retention behavior in reversed-phase systems is discussed as supporting information for identification of the metabolite. The first and basic step in the interpretation of mass spectra is always the molecular weight (MW) determination based on the presence of protonated molecules [M+H]⁺ and sometimes adducts with ammonium or alkali-metal ions, observed in the positive-ion full-scan mass spectra. The MW determination can be confirmed by the [M-H]^- ion for metabolites providing a signal in negative-ion mass spectra. MS/MS is a worthy tool for further structural characterization because of the occurrence of characteristic fragment ions, either MS ⁿ analysis for studying the fragmentation patterns using trap-based analyzers or high mass accuracy measurements for elemental composition determination using time of flight based or Fourier transform mass analyzers. The correlation between typical functional groups found in phase I and phase II drug metabolites and corresponding neutral losses is generalized and illustrated for selected examples. The choice of a suitable ionization technique and polarity mode in relation to the metabolite structure is discussed as well.     

Comparison of methods with respect to efficiencies, recoveries, and quantitation of mercury species interconversions in food demonstrated using tuna fish

Eight different analytical extraction procedures commonly used to extract mercury species from biological samples were evaluated by analyzing Tuna Fish Tissue Certified Reference Material (ERM-CE464) certified for the content of total mercury and methylmercury. Speciated isotope dilution mass spectrometry (SIDMS; US Environmental Protection Agency’s method 6800) was utilized to evaluate and effectively compensate for potential errors during measurement and accurately quantify mercury species using all the extraction methods. SIDMS was used to accurately evaluate species transformations during sample pretreatment, preparation and analysis protocols. The extraction methods tested in this paper were based on alkaline extraction with KOH or tetramethylammonium hydroxide; acid leaching with HCl, HNO₃ or CH₃COOH; extraction with l-cysteine hydrochloride; and enzymatic digestion with protease XIV. Detection of total mercury and mercury species from all extraction methods was carried out by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography–ICP-MS, respectively. Microwave-assisted extraction and ultrasound-assisted extraction were found to be the most efficient alkaline digestion protocols that caused the lowest levels of transformation of mercury species (6% or less). Extraction with 5 M HCl or enzymatic digestion with protease resulted in the second-highest extraction efficiency, with relatively lower transformation of methylmercury to inorganic mercury (3 and 1.4%, respectively). Despite frequent use of acid leaching for the extraction of mercury species from tuna fish samples, the lowest extraction efficiencies and the highest mercury species transformation were obtained when microwave-assisted extraction with 4 M HNO₃ or CH₃COOH was used. Transformations as high as 30% were found using some literature protocols; however, all the extractions tested produced accurate quantitation when corrected in accordance with the SIDMS method standardized in the US Environmental Protection Agency’s method 6800. Figure Determinative CRM Tuna Fish Tissue Methylmercury Calibration vs. Determinative Calculation.     

Application of LC and GC hyphenated with mass spectrometry as tool for characterization of unknown derivatives of isoflavonoids

Polyphenols belonging to the class of secondary metabolites of plants and microorganisms play an important role as bioactive food constituents as well as contaminants. Structure elucidation of polyphenols in plant extracts or polyphenol metabolites, especially those arising during biotransformation, still represents a challenge for analytical chemistry. Various approaches have been proposed to utilize fragmentation reactions in connection with mass spectrometry (MS) for structural considerations on polyphenolic targets. We compiled and applied specific liquid chromatography (LC)–electrospray ionization in positive mode [ESI(+)]–tandem MS (MS/MS) and gas chromatography (GC)–(electron impact, EI)–MS/MS fragmentation reactions with a special focus on the analysis of isoflavones, whereby this technique was also found to be extendable to determine further polyphenols. For ESI(+)-MS the basic retro-Diels–Alder (rDA) fragmentation offers information about the substitution pattern in the A- and B-rings of flavonoids and the elimination of a protonated 4-methylenecyclohexa-2,5-dienone (m/z = 107) fragment can be used as a diagnostic tool for many isoflavanones. For GC-(EI)-MS/MS analysis after derivatization of the analytes to their trimethylsilyl ethers, the elimination of methyl radicals, tetramethylsilane groups or the combined loss of two methyl groups can be shown to be specific for certain substitution patterns in polyphenols. The applicability of the fragmentation reactions presented is demonstrated exemplarily for three derivatives of the isoflavone irilone. With the help of these fragmentation reactions of the two MS techniques combined, a reliable identification of polyphenols is possible. Especially in such cases where NMR cannot be utilized owing to low analyte amounts being available or prior to purification, valuable information can be obtained. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Ronald Maul and Nils Helge Schebb contributed equally to this work.     

Enhancement of enzymatic digestion of Antarctic krill and successive extraction of selenium organic compounds by ultrasound treatment

In a previous work we described the isolation of selenium organic species from Antarctic krill after enzymatic hydrolysis. In this paper we present the results of the influence of ultrasonication on the enzymatic treatment and the successive isolation of selenomethionine. We showed that ultrasound-assisted enzymatic digestion leads to quantitative release of selenium in the soluble fraction and recovery of selenomethionine from the krill protein within a time 2 orders of magnitude shorter. The solubilised sample was analysed by size-exclusion chromatography and the selenomethionine content was quantified by high-performance liquid chromatography–inductively coupled plasma mass spectrometry. In total, 99% of the selenomethionine in the krill hydrolysate was recovered from the chromatographic fractions. It corresponds to 35% of the total selenium content in Antarctic krill. Monitoring by microscopy of the changes in the structure of the krill samples during ultrasonication suggested that the enhancement of the ultrasound-assisted enzymatic reaction was mainly due to decrease of mass transfer limitations. A reference experiment for ultrasound-assisted enzymatic digestion of cell-free protein in a homogeneous system does not exclude direct influence of the ultrasound energy on the enzyme–substrate interaction.     

LC–MS Determination and Pharmacokinetic Study of a Novel Sulfonylurea: Potential Hypoglycemic Agent in Rat Plasma

To support preclinical pharmacokinetic investigation of 1-[4-[2-(4-bromobenzene-sulfonaminoethyl)phenylsufonyl]-3-(trans-4-methylcyclohexyl)urea (G004), a rapid, sensitive and specific high-performance liquid chromatography–electrospray ionization mass spectrometry (LC–ESI-MS) method was developed and validated. Glibenclamide was employed as internal standard. After liquid–liquid extraction the analyte was analyzed on a Kromasil C₁₈ column (150 × 2.0 mm i.d.) with a mobile phase consisted of acetonitrile–water (0.05% acetic acid), 30:70 (v/v). The flow rate was 0.2 mL min⁻¹. Detection was performed on a quadrupole mass spectrometer using an electrospray ionization interface and the selected-ion monitoring (SIM) mode. The retention time was about 3.5 and 4.2 min for Glibenclamide and G004, respectively. The assay was linear over the concentration range of 2.0–500.0 ng mL⁻¹. Extraction Recovery of G004 in rat plasma was more than 87%. The intra- and inter-assay precision was lower than 11.5% (CV). This validated method was successfully applied to the pharmacokinetics of G004 in rats.     

Determination of 6-Benzyladenine in Bean Sprout by LC–ESI-IT-MS–MS

A rapid and sensitive method has been developed and validated to determine 6-benzyladenine (6-BA) residues in bean sprout using high-performance liquid chromatography coupled with electrospray ionization ion trap tandem mass spectrometry. Liquid–liquid extraction, using acidified methanol, was used to isolate 6-BA from the sample matrix. The separation was carried out on a Zorbax SB C₁₈ column (150 mm × 4.6 mm i.d., 5 μm) with 0.1% acetic acid/methanol (25:75 v/v) as mobile phase in isocratic mode. The quantitation of 6-BA was based on fragmentation of the molecular ion at m/z 226.1 to a product ion at m/z 91.1. In addition, the recoveries of three extraction solvents by ultrasound extraction and conventional extraction method were compared, and it was found that acidified methanol as the extraction solvent was the best. The calibration curve was linear (r ² > 0.997) in the concentration range of 0.04–10.0 ng mL⁻¹ with a lower limit of quantification of 0.5 ng g⁻¹ for 6-BA in bean sprout. Intra-day and inter-day relative standard deviations (RSDs) were less than 7.1 and 9.8%. Recoveries of 6-BA were between 85.0 and 88.5%. This assay has been successfully applied to the determination of trace 6-BA residues in bean sprout and monitoring the market in Ningbo, China.     

A novel method for the rapid determination of polyethoxylated tallow amine surfactants in water and sediment using large volume injection with high performance liquid chromatography and tandem mass spectrometry

Polyethoxylated tallow amine (POEA) surfactants have been used in many glyphosate-based herbicide formulations for agricultural, industrial and residential weed control. The potential for release of these compounds into the environment is of increasing concern due to their toxicity towards aquatic organisms. Current methods for analysis of POEA surfactants require significant time and effort to achieve limits of quantification that are often higher than the concentrations at which biological effects have been observed (as low as 2 ng mL⁻¹). We have developed a rapid and robust method for quantifying the POEA surfactant mixture MON 0818 at biologically relevant concentrations in fresh water, sea water and lake sediment using reversed phase high-performance liquid chromatography and electrospray ionization-tandem mass spectrometry. Water samples preserved by 1:1 v/v dilution with methanol are analyzed directly following centrifugation. Sediment samples undergo accelerated solvent extraction in aqueous methanol prior to analysis. Large volume (100 μL) sample injection and multiple reaction monitoring of a subset of the most abundant POEA homologs provide limits of quantification of 0.5 and 2.9 ng mL⁻¹ for MON 0818 in fresh water and sea water, respectively, and 2.5 ng g⁻¹ for total MON 0818 in lake sediment. Average recoveries of 93 and 75% were achieved for samples of water and sediment, respectively spiked with known amounts of MON 0818. Precision and accuracy for the analysis of water and sediment samples were within 10 and 16%, respectively based upon replicate analyses of calibration standards and representative samples. Results demonstrate the utility of the method for quantifying undegraded MON 0818 in water and sediment, although a more comprehensive method may be needed to identify and determine other POEA mixtures and degradation profiles that might occur in the environment.     

Simple, Sensitive and Rapid LC–ESI–MS Method for the Quantitation of Olprinone in Rat Plasma

Olprinone is a phosphodiesterase (PDE)-3 inhibitor. This paper describes a simple, selective and sensitive method for the quantification of olprinone in rat plasma using a liquid–liquid extraction procedure followed by liquid chromatography mass spectrometric (LC–MS) analysis. The method had an advantage of high sensitivity. Analyses were conducted at a flow rate of 0.25 mL min⁻¹ by a gradient elution. The detection utilized selected ion monitoring in the positive ion mode at m/z 251.0 and 344.0 for the protonated molecular ions of olprinone and the internal standard, respectively. The quantitation limit for olprinone in rat plasma was 0.5 ng mL⁻¹. The linearity was also excellent over the concentration range of 0.5–100 ng mL⁻¹ of olprinone. The intra- and inter-day precision (relative standard deviation (RSD) %) was lower than 10%, and accuracy ranged from 90 to 110%. This developed method was successfully applied to analysis of olprinone in biological fluids.     

Determination of volatile organic hydrocarbons in water samples by solid-phase dynamic extraction

In the present study a headspace solid-phase dynamic extraction method coupled to gas chromatography–mass spectrometry (HS-SPDE-GC/MS) for the trace determination of volatile halogenated hydrocarbons and benzene from groundwater samples was developed and evaluated. As target compounds, benzene as well as 11 chlorinated and brominated hydrocarbons (vinyl chloride, dichloromethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, bromoform) of environmental and toxicological concern were included in this study. The analytes were extracted using a SPDE needle device, coated with a poly(dimethylsiloxane) with 10% embedded activated carbon phase (50-μm film thickness and 56-mm film length) and were analyzed by GC/MS in full-scan mode. Parameters that affect the extraction yield such as extraction and desorption temperature, salting-out, extraction and desorption flow rate, extraction volume and desorption volume, the number of extraction cycles, and the pre-desorption time have been evaluated and optimized. The linearity of the HS-SPDE-GC/MS method was established over several orders of magnitude. Method detection limits (MDLs) for the compounds investigated ranged between 12 ng/L for cis-dichloroethylene and trans-dichloroethylene and 870 ng/L for vinyl chloride. The method was thoroughly validated, and the precision at two concentration levels (0.1 mg/L and a concentration 5 times above the MDL) was between 3.1 and 16% for the analytes investigated. SPDE provides high sensitivity, short sample preparation and extraction times and a high sample throughput because of full automation. Finally, the applicability to real environmental samples is shown exemplarily for various groundwater samples from a former waste-oil recycling facility. Groundwater from the site showed a complex contamination with chlorinated volatile organic compounds and aromatic hydrocarbons. Figure SPDE Principle     

Hyphenation of reverse-phase HPLC and ICP-MS for metabolite profiling—application to a novel antituberculosis compound as a case study

In this study, a high-performance liquid chromatography (HPLC) inductively coupled plasma (ICP) mass spectrometry (MS) method was developed intended for use in metabolism studies of bromine-containing drugs, administered to test animals (or test persons). As a case study, the method was applied to a new antituberculosis compound, the bromine-containing diarylquinoline R207910. A method has been proposed to overcome the incompatibilities between the high organic solvent content (45%CH₃OH and 45% CH₃CN) used in the reverse-phase liquid chromatography (LC) separation on one hand and the limitations of the ICP on the other hand. Therefore, several instrument modifications had to be made. For the introduction of the column effluent, a combination of a perfluoroalkoxy LC nebulizer with a PC³ Peltier-cooled inlet system (operated at 2 °C) was used. Additionally, the standard injector tube (internal diameter 2 mm) was replaced by an injector tube with an internal diameter of 1 mm and to avoid carbon build-up on the interface cones and the torch, the nebulizer gas was admixed with 6% v/v of oxygen. After optimization of the method, HPLC-ICP-MS was applied for metabolite profiling of faeces samples after dosing of ¹⁴C-radiolabelled R207910 to dogs and rats. To evaluate the method developed, the HPLC-ICP-MS results were compared with those of HPLC with UV spectrophotometric and ¹⁴C radiochemical detection. As the HPLC-ICP-MS method gave rise to a higher selectivity than HPLC with UV detection and to a better detection limit (5 ng R207910) than the method with radiochemical detection (65 ng R207910), it can be concluded that ICP-MS can be used as a good alternative to the more traditional detection methods, even when a mobile phase with high organic solvent content has to be used in the LC separation.     

Application of LC–MS for Determination of Indole and 3-Methylindole in Porcine Adipose Tissue

A new method is described for simultaneous determination of 3-methylindole (3MI) and indole in porcine adipose tissue. Sample preparation included liquid–liquid extraction with n-hexane and 75% aqueous acetonitrile. The acetonitrile extracts were analysed by liquid chromatography–mass spectrometry (LC–MS) using atmospheric pressure chemical ionization (APCI) with selective ion monitoring of protonated ions [M + H]⁺. This method showed excellent linearity over the concentration range tested (from 2 to 500 ng mL⁻¹ for 3MI and from 1 to 500 ng mL⁻¹ for indole) and good accuracy (recovery of 92 ± 10% for 3MI and 91 ± 10% for indole). This new LC–MS method was compared with traditional colorimetric method for 3MI equivalent. Additionally, the correlation between 3MI concentrations in adipose tissue and plasma was studied. The described LC–MS method can be used to quantify 3MI and indole in porcine adipose tissue in various endocrinological or meat science studies.     

Determination of 2-isopropyl thioxanthone and 2-ethylhexyl-4-dimethylaminobenzoate in milk: comparison of gas and liquid chromatography with mass spectrometry

Liquid chromatography–tandem mass spectrometry (LC-MS/MS) and gas chromatography–mass spectrometry (GC-MS) have been compared for the analysis of 2-isopropyl thioxanthone (ITX) and 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB). Pressurized liquid extraction (PLE) was applied for the extraction of ITX and EHDAB from milk and milk-based beverages. Samples were homogenized with sea sand and anhydrous sodium sulfate, and were extracted with ethyl acetate at 100 °C and 10.3 × 10⁶ Pa in one cycle of 10 min at 90% flush. Both, GC-MS and LC-MS/MS were suitable to determine these photoinitiators in the PLE extracts, providing appropriate identification and quantification. The recoveries obtained ranged from 70 to 99% for ITX and from 70 to 95% for EHDAB. These recoveries were equal as those obtained by a conventional liquid–liquid partitioning with acetonitrile and tert-butyl methyl ether–hexane. The quantification limits using GC-MS, based on a signal-to-noise ratio of 10, were 0.5 μg/L for ITX and 1 μg/L for EHDAB. The repeatability of the method, as indicated by the relative standard deviations, was within the range 0.9–16.1%. The same parameters calculated using LC-MS/MS result in quantification limits of 0.1 μg/L for ITX and 0.02 μg/L for EHDAB and repeatability within the range 5.2–19.4%. These results pointed out that both techniques are appropriate to determine these compounds in food samples. The method was applied to milk and milk-based beverages from different supermarkets. The ITX and EHDAB contents ranged from 2.5 to 325 μg/L and from 8 to 126 μg/L, respectively. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Simple and Rapid Determination of Benzoylphenylurea Pesticides in River Water and Vegetables by LC–ESI-MS

Liquid chromatography with electrospray mass spectrometry (LC–ESI-MS) instrumentation equipped with a single quadrupole mass filter has been used to determine several benzoylphenylurea insecticides (diflubenzuron, triflumuron, hexaflumuron, lufenuron and flufenoxuron). Chromatographic and MS parameters were optimised to obtain the best sensitivity and selectivity for all pesticides. Solid-phase extraction (SPE) using C₁₈ cartridges was applied for preconcentration of pesticide trace levels in river water samples. Recoveries of benzoylphenylurea pesticides from spiked river water (0.01 and 0.025 μg L⁻¹) were between 73 and 110% and detection limits were between 3.5 and 7.5 ng L⁻¹. The applicability of the method to the determination of benzoylphenylurea insecticides in spiked cucumber, green beans, tomatoes and aubergines was evaluated. Samples were extracted into dichloromethane without any clean-up step. The limits of detection ranged from 1.0 to 3.2 ng mL⁻¹ (0.68 and 2.13 μg kg⁻¹ in the vegetable samples). Mean recoveries ranged from 79 to 114% at spiking levels of 0.01 and 0.03 mg kg⁻¹. The method was applied to determine traces of benzoylphenylureas in both river water and vegetable samples with precision values lower than 10%. Interferences due to the matrix effect were overcome using matrix-matched standards.     

Determination of Pregabalin in Human Plasma Using LC-MS-MS

A bioanalytical method has been developed and validated for determination of pregabalin in human plasma. The analytical method consists in the precipitation of plasma sample with trichloro acetic acid (20% v/v solution in water), followed by the determination of pregabalin by an LC-MS-MS method using gabapentin as internal standard. Separation was achieved on a Gemini C₁₈ 50 mm × 2.0 mm (3 μm) column with an isocratic mobile phase consisting of methanol–water (98:2, v/v) with 0.5% v/v formic acid. Protonated ions formed by a turbo ionspray in positive mode were used to detect analyte and internal standard. The MS-MS detection was by monitoring the fragmentation of 160.2→55.1 (m/z) for pregabalin and 172.2→67.1 (m/z) for gabapentin on a triple quadrupole mass spectrometer. The assay was calibrated over the range 0.1–15.0 μg mL⁻¹ with correlation coefficient of 0.9998. Validation data showed intra-batch (n = 6) CV% ≤ 6.89 and RE (%) between −4.17 and +3.08 and inter-batch (n = 18) CV% < 9.09 and RE (%) between −3.0 and +10.00. Mean extraction recovery were 80.45–89.12% for three QC samples and 87.56% for IS. Plasma samples were stable for three freeze–thaw cycles, or 24 h ambient storage, or 1 and 3 months storage at −20 °C. Processed sample (ready for injection) were stable up to 72 h at autosampler (4 °C). This method has been used for analyzing plasma samples from a bioequivalence study with 18 volunteers.     

Bioanalytical procedures for determination of drugs of abuse in blood

Determination of drugs of abuse in blood is of great importance in clinical and forensic toxicology. This review describes procedures for detection of the following drugs of abuse and their metabolites in whole blood, plasma or serum: Δ9-tetrahydrocannabinol, 11-hydroxy-Δ9-tetrahydrocannabinol, 11-nor-9-carboxy-Δ9-tetrahydrocannabinol, 11-nor-9-carboxy-Δ9-tetrahydrocannabinol glucuronide, heroin, 6-monoacetylmorphine, morphine, morphine-6-glucuronide, morphine-3-glucuronide, codeine, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine, N-ethyl-3,4-methylenedioxyamphetamine, 3,4-methylenedioxyamphetamine, cocaine, benzoylecgonine, ecgonine methyl ester, cocaethylene, other cocaine metabolites or pyrolysis products (norcocaine, norcocaethylene, norbenzoylecgonine, m-hydroxycocaine, p-hydroxycocaine, m-hydroxybenzoylecgonine, p-hydroxybenzoylecgonine, ethyl ecgonine, ecgonine, anhydroecgonine methyl ester, anhydroecgonine ethyl ester, anhydroecgonine, noranhydroecgonine, N-hydroxynorcocaine, cocaine N-oxide, anhydroecgonine methyl ester N-oxide). Metabolites and degradation products which are recommended to be monitored for assessment in clinical or forensic toxicology are mentioned. Papers written in English between 2002 and the beginning of 2007 are reviewed. Analytical methods are assessed for their suitability in forensic toxicology, where special requirements have to be met. For many of the analytes sensitive immunological methods for screening are available. Screening and confirmation is mostly done by gas chromatography (GC)–mass spectrometry (MS) or liquid chromatography (LC)–MS(/MS) procedures. Basic information about the biosample assayed, internal standard, workup, GC or LC column and mobile phase, detection mode, and validation data for each procedure is summarized in two tables to facilitate the selection of a method suitable for a specific analytic problem.     

Simultaneous analysis of different classes of phytohormones in coconut (Cocos nucifera L.) water using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry after solid-phase extraction

Coconut (Cocos nucifera L.) water, which contains many uncharacterized phytohormones is extensively used as a growth promoting supplement in plant tissue culture. In this paper, a high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of various classes phytohormones, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), abscisic acid (ABA), gibberellic acid (GA), zeatin (Z), N⁶-benzyladenine (BA), α-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) in young coconut water (CW). The analysis was carried out using a reverse-phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid, pH adjusted to 3.2 with triethylamine (TEA)) modified by methanol, and solute detection made at 265 nm wavelength. The method was validated for specificity, quantification, accuracy and precision. After preconcentration of putative endogenous phytohormones in CW using C₁₈ solid-phase extraction (SPE) cartridges, the HPLC method was able to screen for putative endogenous phytohormones present in CW. Finally, the identities of the putative phytohormones present in CW were further confirmed using independent liquid chromatography–tandem mass spectrometry (LC–MS/MS) equipped with an electrospray ionization (ESI) interface.