Positive Electrospray Tandem Mass Spectrometry Research Articles

Determination of Mildronate in Human Plasma and Urine by UPLC–Positive Ion Electrospray Tandem Mass Spectrometry

A simple, rapid, and selective method to determine the concentration of mildronate in human plasma and urine using ultra performance liquid chromatography–tandem mass spectrometry (UPLC-MS-MS) was developed and validated. The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization at m/z 147.2–58.0 for mildronate and m/z 147.2–87.8 for the internal standard, carbachol. The UPLC separation was carried out with a UPLC BEH HILIC column. The mobile phase consisted of 0.08% formic acid in 30 mM ammonium acetate solution and acetonitrile (23:77, v/v). Plasma samples were extracted from plasma by protein precipitation and urine samples were diluted with the mobile phase. The analysis time was 3.5 min for each sample. Linear calibration curves ranged from 0.10 to 100.00 μg mL−1 in human plasma and 0.50 to 600.00 μg mL−1 in urine. The method had been successfully applied to a pharmacokinetic study in healthy volunteers. After single intravenously administration of 250, 500, and 750 mg mildronate, the elimination half-life (t1/2) were (2.74 ± 0.67), (4.86 ± 0.82) and (5.16 ± 0.77) h, respectively. The t1/2 for the 250 mg dose did vary significantly with other dosages (P < 0.05), mildronate may have non-linear pharmacokinetics in humans.

Biosynthesis of 14,15‐Hepoxilins in Human L1236 Hodgkin Lymphoma Cells and Eosinophils

Hepoxilins are epoxy alcohols synthesized through the 12-lipoxygenase (12-LO) pathway in animal cells. The epidermis is the principal source of hepoxilins in humans. Here we report on the formation of novel hepoxilin regioisomers formed by the 15-LO pathway in human cells. The Hodgkin lymphoma cell line L1236 possesses high 15-lipoxygenase-1 (15-LO-1) activity and incubation of L1236 cells with arachidonic acid led to the formation of 11(S)-hydroxy-14(S),15(S)-epoxy 5(Z),8(Z),12(E) eicosatrienoic acid (14,15-HxA(3) 11(S)) and 13(R)-hydroxy-14(S),15(S)-epoxy 5(Z),8(Z),11(Z) eicosatrienoic acid (14,15-HxB(3) 13(R)). In addition, two hitherto unidentified products were detected and these products were collected and analyzed by positive ion electrospray tandem mass spectrometry. These metabolites were identified as 11(S),15(S)-dihydroxy-14(R)-glutathionyl-5(Z),8(Z),12(E)-eicosatrienoic acid (14,15-HxA(3)-C) and 11(S),15(S)-dihydroxy-14(R)-cysteinyl-glycyl-5(Z),8(Z),12(E)-eicosatrienoic acid (14,15-HxA(3)-D). Incubation of L1236 cells with synthetic 14,15-HxA(3) 11(S) also led to the formation of 14,15-HxA(3)-C and 14,15-HxA(3)-D. Several soluble glutathione transferases, in particular GST M1-1 and GST P1-1, were found to catalyze the conversion of 14,15-HxA(3) to 14,15-HxA(3)-C. L1236 cells produced approximately twice as much eoxins as cysteinyl-containing hepoxilins upon stimulation with arachidonic acid. Human eosinophils, nasal polyps and dendritic cells selectively formed 14,15-HxA(3) 11(S) and 14,15-HxB(3) 13(R) stereoisomers, but not cysteinyl-containing hepoxilins, after stimulation with arachidonic acid. Furthermore, purified recombinant 15-LO-1 alone catalyzed the conversion of arachidonic acid to 14,15-HxA(3) 11(S) and 14,15-HxB(3) 13(R), showing that human 15-LO-1 possesses intrinsic 14,15-hepoxilin synthase activity.

A simple and sensitive liquid chromatography–mass spectrometry routine method for determination of clarithromycin in human plasma: Application to a clinical pharmacokinetic study

A simple and sensitive liquid chromatography-mass spectrometry (LC-MS) method was developed for the routine determination of Clarithromycin in human plasma, with Alprazolam as the internal standard. The separation was carried out on an Phenomenex (C18 100 × 4.6 mm, i.d 5 µm) column, with Acetonitrile and 10 mM Ammonium acetate Buffer solution (95:5) as the mobile phase under isocratic conditions at a flow rate of 0.2 mL/min. Detection of the analytes was achieved using positive ion electrospray tandem mass spectrometry in selected reaction monitoring (SRM) mode. The standard curves were linear (r2 > 0.99) over the concentration range of 300–5000 ng/mL. The intra- and inter-day precision (RSD) values were below 15%. The method is validated for the estimation of Clarithromycin in human plasma over a concentration range of 300–5000 ng/mL. Expected recoveries were observed. Limit of detection of the methods is 3.0 ng/ mL and limit of quantitation is 10.0 ng/mL that shows that the developed method has adequate...

Improved method for the determination of cyclic guanosine monophosphate (cGMP) in human plasma by LC–MS/MS

Cyclic guanosine monophosphate (cGMP) is an important second messenger molecule involved in gating ion channels and activating protein kinases. Here, we describe a validated LC–MS/MS method for the quantification of cGMP in human plasma, utilizing a stable isotope labeled analogue of cGMP as I.S. Plasma samples were extracted and concentrated by weak anion exchange solid phase extraction and the extracts were chromatographically separated on a porous graphitic carbon column. The analytes were detected by positive electrospray ionization and tandem mass spectrometry. The calibration function was linear in the range 1–20 nM and the intra- and inter-day precision showed relative standard deviations of better than 2 and 6%, respectively. The accuracy was always better than 4%. Plasma concentrations in healthy human subjects determined with this method were 3.92 ± 1.17 nM ( n = 20). The method was, due to its isotope labeled I.S., matrix independent.

Mass spectrometry of the photolysis of sulfonylurea herbicides in prairie waters

This review of mass spectrometry of sulfonylurea herbicides includes a focus on studies relevant to Canadian Prairie waters. Emphasis is given to data gaps in the literature for the rates of photolysis of selected sulfonylurea herbicides in different water matrices. Specifically, results are evaluated for positive ion electrospray tandem mass spectrometry with liquid chromatography separation for the study of the photolysis of chlorsulfuron, tribenuron-methyl, thifensulfuron-methyl, metsulfuron-methyl, and ethametsulfuron-methyl. LC-MS/MS is shown to be the method of choice for the quantification of sulfonylurea herbicides with instrumental detection limits ranging from 1.3 to 7.2 pg (on-column). Tandem mass spectrometry coupled with the use of authentic standards likewise has proven to be well suited for the identification of transformation products. To date, however, the power of time-of-flight MS and ultrahigh resolution MS has not been exploited fully for the identification of unknown photolysis products. Dissipation of the herbicides under natural sunlight fit pseudo-first-order kinetics with half-life values ranging from 4.4 to 99 days. For simulated sunlight, radiation wavelengths shorter than 400 nm are required to induce significant photolytic reactions. The correlation between field dissipation studies and laboratory photolysis experiments suggests that photolysis is a major pathway for the dissipation of some sulfonylurea herbicides in natural Prairie waters.

Differentiation of isomeric Lewis blood groups by positive ion electrospray tandem mass spectrometry

Lewis histo-blood group antigens are one of the major classes of biologically active oligosaccharides. In this work, underivatized Lewis blood groups were studied by electrospray tandem mass spectrometry (ESI–MSn) in the positive mode with three different mass analyzers: Q-TOF (quadrupole time-of-flight), QqQ (triple quadrupole), and LIT (linear ion trap). It was observed that, under collision-induced fragmentations, type 1 Lewis antigens (Lea and Leb) could be distinguished from type 2 (Lex and Ley) on the basis of specific fragmentations of the GlcNAc unit. Whereas O-4-linked sugars of the GlcNAc are lost as residues, the O-3-linked sugars undergo fragmentation both as sugar units and as sugar residues (unit −18Da). Type 2 Lewis antigens also showed a characteristic cross-ring cleavage 0,2A2 of the GlcNAc. As a result, the product ions at m/z 388 and 305, characteristic of Lex, and m/z 372, characteristic of Lea, are proposed to distinguish the trisaccharide isomers Lex/Lea. Also, the product ions at m/z 534 and 305, characteristic of Ley, and m/z 372, characteristic of Leb, are proposed to distinguish the tetrasaccharide isomers Leb/Ley. These diagnostic fragment ions were further applied in the identification of Lewis type 2 antigens (Lex and Ley) in the lipopolysaccharide of the human gastric pathogen, Helicobacter pylori.

Liquid chromatography–tandem mass spectrometry method for the quantification of dimebon in rat plasma and brain tissue

A sensitive high-performance liquid chromatography–positive ion electrospray tandem mass spectrometry method was developed and validated for the quantification of dimebon in rat plasma and brain tissue. Following liquid–liquid extraction, the analyte was separated using a gradient mobile phase on a reversed phase column and analyzed by MS/MS in the multiple reaction monitoring mode using the respective [M + H] + ions, m/ z 320–277 for dimebon and m/ z 407–100 for the internal standard. The assay exhibited a linear dynamic range of 0.25–250 ng/mL for dimebon in rat plasma and brain tissue. Acceptable precision (<11%) and accuracy (100 ± 7%) were obtained for concentrations over the standard curve range. A run time of 2.5 min for each sample made it possible to analyze more than 250 samples per day. The method was successfully applied to quantify dimebon concentrations in a rodent pharmacokinetic study. Moreover, it can be believed that the assay method in rat plasma would facilitate the ease of adaptability of dimebon quantification in human plasma for clinical trials.

Confirmatory method for the determination of nandrolone and trenbolone in urine samples using immunoaffinity cleanup and liquid chromatography–tandem mass spectrometry

A confirmatory method for the simultaneous determination of nandrolone (α and β) and trenbolone (α and β) in urine samples by liquid chromatography electrospray mass spectrometry (LC–MS-MS) was developed. After an enzymatic deconjugation, the urine was subjected to a one-step cleanup on a commercially available immunoaffinity chromatography cartridge. The analytes were detected by liquid chromatography–positive ion electrospray tandem mass spectrometry using deuterium labelled internal standards. The analytical procedure was applicable to bovine and swine urine samples. The procedure was validated as a quantitative confirmatory method according to the Commission Decision 2002/657/EC criteria. The results obtained showed that the method was suitable for statutory residues testing regarding the following performance characteristics: instrumental linearity, specificity, precision (repeatability and intra-laboratory reproducibility), recovery, decision limit (CCα), detection capability (CCβ) and ruggedness. The decision limits (CCα) obtained, were between 0.54 and 0.60 μg L −1; the recovery was above 64% for all the analytes. Repeatability was between 1.6% and 5.7% and within-laboratory reproducibility between 1.6% and 6.0% for all the steroids.

LC–MS/MS Assay of Quinapril and its Metabolite Quinaprilat for Drug Bioequivalence Evaluation: Prospective, Concurrential and Retrospective Method Validation

The bioequivalence of two pharmaceutical formulations containing 10 mg quinapril was assessed by assaying the untransformed drug and its active metabolite quinaprilat from plasma samples. A gradient elution liquid chromatographic separation coupled to positive atmospheric pressure electrospray ionization and tandem mass spectrometry detection was used and validated. Sample preparation is simple and uses protein precipitation through addition of an acetonitrile:methanol (8:2 v/v) mixture. The method has a run time of 6.3 min. Carvedilol was used as an internal standard. The multiple reactions monitoring mode was used for both quantitation and structural confirmation of target compounds. Linear 1/x²-weighted regressions characterize detector response function up to concentrations of 1000 ng/ml for quinapril and 2000 ng/ml for quinaprilat. Low limits of quantitation of 5 ng/ml for quinapril and 10 ng/ml for quinaprilat were found. Intra- and inter-day variability of the results were found below 15%. Long- (-20°C/6 months) and short-term (25°C/48 h) stability of analytes in plasma, as well as freeze and thaw stability (six cycles) were demonstrated. The method was found to be selective, precise, accurate and robust when applied to a large number of unknown samples.

A sensitive method for the determination of entecavir at picogram per milliliter level in human plasma by solid phase extraction and high-pH LC–MS/MS

Entecavir is a guanine nucleoside analogue used in the treatment of hepatitis B virus (HBV) infection. In this paper, we describe an LC–MS/MS method that was developed and validated for the quantitation of entecavir in human EDTA plasma with both high sensitivity (lower limit of quantitation (LLOQ) of 5 pg/mL) and a wide concentration range (5000-fold) intended for low dose ascending clinical studies. High enrichment was achieved by taking advantage of the excellent loading capacity and reproducibility of Oasis HLB 96-well solid phase extraction plate, which allowed 1 mL of plasma samples to be processed in two equal sequential loading steps. Lobucavir, a structural analogue, was used as the internal standard. A filtration step following the reconstitution proved to be vital for the method robustness. The analyte and internal standard were separated on an Xterra MS C18 column with a gradient elution and high-pH mobile phases. Analytes were detected by positive ion electrospray tandem mass spectrometry. The high-pH mobile phase provided both excellent analyte on-column retention and peak shape, leading to the desired sensitivity. Validation results show good intra-assay (12.3%CV) and inter-assay (3.1%CV) precisions, and good assay accuracy (±7.6%Dev). Recovery was high (∼80%), however, the large volume of plasma used did result in a considerable matrix effect (∼0.45) which was well compensated by the analog internal standard. The method was applied to sample analysis of a Phase I clinical study.

Determination of 5-nitroimidazoles and corresponding hydroxy metabolites in swine kidney by ultra-performance liquid chromatography coupled to electrospray tandem mass spectrometry

A rapid, sensitive and reliable multi-residue method for the simultaneous determination of four 5-nitroimidazoles (NIIMs) and their three corresponding metabolites in swine kidney was developed and validated. The compounds of interest were extracted from tissues with ethyl acetate. The crude extracts were subject to liquid–liquid partition with hexane followed by solid-phase extraction using mixed-mode strong cation-exchange column. Chromatographic separation was achieved on an AcQuity BEH C 18 column and was completed within 4 min for each injection. Data acquisition under positive electrospray tandem mass spectrometry was performed by applying multiple reaction monitoring for both identification and quantification. Mean relative recoveries from fortified samples ranged from 83% to 111%, with coefficients of variation lower than 12%. The limits of detection and quantification for the NIIMs were in the range of 0.05–0.5 and 0.1–0.5 μg kg −1, respectively.

Validation of a liquid chromatography–tandem mass spectrometric assay for the quantitative determination of hydrastine and berberine in human serum

A high throughput liquid chromatography/tandem mass spectrometry (LC–MS/MS) method for the simultaneous determination of berberine and hydrastine in human serum, after oral administration of goldenseal ( Hydrastis canadensis L.), was developed using simple acetonitrile treatment of serum samples. Noscapine served as the internal standard. Lower limit of quantification for both analytes was 0.1 ng mL −1 using positive ion electrospray tandem mass spectrometry (MS/MS). The intra-day ( n = 5) accuracy and precision of the method for hydrastine was 82 ± 8.8%, 97.9 ± 2.4% and 96.2 ± 3.3%, respectively. The inter-day ( n = 4) accuracy and precision for hydrastine was 90.0 ± 15.17%, 99.9 ± 7.1% and 98 ± 6.54%, respectively. For berberine quantitation intra-day accuracy and precision was 96.0 ± 8.4%, 92.5 ± 4.7% and 94.4 ± 3.7%, respectively. The respective values for inter-day quantitation were 91.0 ± 8.4%, 94.3 ± 4.7% and 94.4 ± 3.7%. The analytical recovery for hydrastine was 82.4–96.2% and for berberine it was 94.4–96.0%. The analytes and noscapine were stable for 24 h at room temperature (CV 5–10%). Matrix ion effects were studied by post-column infusion of hydrastine and berberine, calculation of calibration curve slope precision was obtained using serum from five different subjects, and by comparison of the response of methanol standards and extracted serum samples. The method was further validated by determination of serum pharmacokinetics of hydrastine and berberine after administration of a single oral dose of goldenseal extract containing 77 mg of hydrastine and 132 mg of berberine.

Quantification of Citalopram or Escitalopram and Their Demethylated Metabolites in Neonatal Hair Samples by Liquid Chromatography-Tandem Mass Spectrometry

Citalopram and escitalopram are highly selective serotonin reuptake inhibitors widely used in the treatment of depression. They exhibit adverse drug reactions and side effects, however, and the development of specific methods for their determination is of great interest in clinical and forensic toxicology. A liquid chromatography-tandem mass spectrometry method has been developed and validated for the assay of citalopram, escitalopram, and their demethylated metabolites in 10-mg hair samples. The analytes were extracted by incubation in methanol and liquid/liquid extraction with diethyl ether/dichloromethane. Gradient elution on a narrow bore C18 column was realized using clomipramine-d3 as an internal standard. Positive ion electrospray ionization and tandem mass spectrometry determination by collision-induced dissociation were performed in an ion trap mass spectrometer. The method exhibited a linear range of 25 to 2000 pg/mg, a quantification limit of 25 pg/mg for all analytes, relative standard deviations in the range of 12.10 to 9.80 (intraassay), and 13.80 to 11.78 (interassay), and accuracies (as percent recovery of the spiked standards) in the range of 90% to 110%; it was applied to the determination of citalopram and escitalopram and their metabolites in hair samples of two newborns to document their in utero exposure to the drugs. The method proved suitable for neonatal hair analysis of citalopram or escitalopram and was applied to two real cases of gestational exposure.

Simplified method for determination of clarithromycin in human plasma using protein precipitation in a 96-well format and liquid chromatography–tandem mass spectrometry

A simplified method to determine clarithromycin concentrations in human plasma using protein precipitation in a 96-well plate and liquid chromatography–tandem mass spectrometry was developed and validated. Plasma proteins were precipitated with acetonitrile and roxithromycin was used as the internal standard. After vortex mixing and centrifugation, the supernatants were directly injected onto a Phenomenex Luna Phenyl–Hexyl column (50 mm × 2.0 mm ID, 3 μm). The mobile phase consisted of water and methanol (30:70, v/v) containing 0.1% formic acid and 5 mM ammonium acetate. The flow rate was 0.22 mL/min and the total run time (injection to injection) was less than 3 min. Detection of the analytes was achieved using positive ion electrospray tandem mass spectrometry in selected reaction monitoring (SRM) mode. The linear standard curve ranged from 100 to 5000 ng/mL and the precision and accuracy (inter- and intra-run) were within 7.9% and 4.9%, respectively. The method was successfully used to determine clarithromycin concentrations in human plasma samples obtained from healthy subjects who were given clarithromycin 500 mg for 3 days. The method is rapid, simple, precise and directly applicable to clarithromycin pharmacokinetic studies.

Trace level determination of selected organophosphorus pesticides and their degradation products in environmental air samples by liquid chromatography-positive ion electrospray tandem mass spectrometry

This paper describes a new analytical method for determination of organophosphorus pesticides (OPs) along with their degradation products involving liquid chromatography (LC) positive ion electrospray (ESI+) tandem mass spectrometry (MS-MS) with selective reaction monitoring (SRM). Chromatography was performed on a Gemini C6-Phenyl (150 mm × 2.0 mm, 3 μ m) with a gradient elution using water-methanol with 0.1% formic acid, 2mM ammonium acetate mobile phase at a flow rate of 0.2 mL min− 1. The LC separation and MS/MS operating conditions were optimized with a total analysis time less than 40 minutes. Method detection limits of 0.1-5 μ g L− 1 for selected organophosphorus pesticides (OP), OP oxon degradation products, and other degradation products: 3,5,6-trichloro-2-pyridinol (TCP); 2-isopropyl-6-methyl-4-pyrimidol (IMP); and diethyl phosphate (DEP). Some OPs such as fenchlorphos are less sensitive (MDL 30 μ g L− 1). Calibration curves were linear with coefficients of correlation better than 0.995. A three-point identification approach was adopted with area from first selective reaction monitoring (SRM) transition used for quantitative analysis, while a second SRM transition along with the ratio of areas obtained from the first to second transition are used for confirmation with sample tolerance established by the relative standard deviation of the ratio obtained from standards. This new method permitted the first known detection of OP oxon degradation products including chlorpyrifos oxon at Bratt's Lake, SK and diazinon oxon and malathion oxon at Abbotsford, BC in atmospheric samples. Atmospheric detection limits typically ranged from 0.2–10 pg m− 3.

Analysis of catecholamines and their metabolites in adrenal gland by liquid chromatography tandem mass spectrometry

Two simple, rapid and specific analytical methods for 13 catecholamines and their metabolites have been developed based on liquid chromatography tandem mass spectrometry in a multiple reaction monitoring mode. Tyrosine, dopamine, dihydroxyphenylalanine, epinephrine, norepinephrine, 3-methoxytyramine, normetanephrine, metanephrine and isoproterenol (internal standard) were separated on a Kromasil™ Cyano analytical column by a mobile phase consisting of 60% (v/v) acetonitrile and 40% (v/v) water adjusted with formic acid to pH 3.0, and detected by positive ionization electrospray tandem mass spectrometry. While vanillymandelic acid, 3,4-dihydroxymandelic acid, homovanillic acid, 3,4-dihydroxyphenylacetic acid, 4-hydroxy-3-methoxyphenylglycol and 5-hydroxy-2-indolecarboxylic acid (internal standard) were separated on a reversed-phase Shim-Pak VP-ODS column with the mobile phase of 60% (v/v) acetonitrile, and 40% (v/v) water adjusted with formic acid to pH 4.5 and detected in the negative ionization electrospray tandem mass spectrometry. The influence of various parameters such as column type and mobile phase composition on separation and sensitivity were investigated. The limits of detection were in the range of 0.5–20 ng mL −1. The mean recoveries determined from three different concentrations of each analyte were above 85.4%. The precision of the method calculated as relative standard deviation was lower than 5.3%. Deduced from the results of real sample analysis, adrenal gland synthesizes and stores the catecholamine hormones norepinephrine and epinephrine.

Fragmentation Study of Globularin Through Positive and Negative ESI/MS, CID/MS, and Tandem MS/MS

The structure of globularin was studied by a mass spectrometric methodology based on the combined use of positive and negative electrospray ionization, collision‐induced dissociation (CID), and tandem mass spectrometry. The mass spectrometry investigation was achieved through in‐source fragmentation of the deprotonated [M−H]−, protonated [M+H]+, lithiated [M+Li]+, sodiated [M+Na]+, and potassium‐cationized [M+K]+ ions. This allowed collision‐induced dissociation spectra of the ionized molecular ions to be obtained to give valuable structural information regarding the nature of both the glycoside and the aglycone moieties and the effect of metal cationization on the CID spectra. Glycosidic fission and ring cleavages of both aglycone and sugar moieties were the major fragmentation pathways observed during collision‐induced dissociation, where the losses of small molecules, the cinnamoyl and the cinnamate parts were also observed. Alkali metal cationization offers additional fragmentation pathways involving cross rings cleavage under CID conditions. Unlike the dissociation of protonated molecular ions, that of metal‐cationized molecules also provides sugar fragments where the C0 + fragment corresponding with the glucose ion was obtained as a major daughter peak for all the studied compounds. Even with low abundance, fragment ions coordinated to K+ were also observed from [M+K]+.

Simultaneous determination of desloratadine and its active metabolite 3-hydroxydesloratadine in human plasma by LC/MS/MS and its application to pharmacokinetics and bioequivalence

A rapid and simple liquid chromatographic-tandem mass spectrometric (LC/MS/MS) method was developed and validated for the simultaneous determination of desloratadine and its active metabolite 3-hydroxydesloratadine concentrations in human plasma. After liquid–liquid extraction with ethyl ether for sample preparation, the chromatographic separation was achieved on a CAPCELL PAK C18 column (50 mm × 2.0 mm, 5 μm, Shiseido). [ 2H 4]desloratadine and [ 2H 4]3-OH desloratadine were used as internal standards. A mobile phase consisted of 5 mM ammonium formate in water, methanol and acetonitrile (50:30:20). Detection was by positive ion electrospray tandem mass spectrometry on a Sciex API3000. A quadratic regression (weighted 1/concentration) gave the best fit for calibration curves over the concentration range 0.05–10 ng/mL for both desloratadine and 3-OH desloratadine. The method was shown to be accurate, rapid and sufficiently sensitive to be successfully applied to a pharmacokinetic and bioequivalent study.

Highly Specific Quantification of Ergotamine in Urine, Blood, and Hair Samples by Liquid Chromatography-Tandem Mass Spectrometry

Ergotamine has been used for therapeutic purposes since the 1950s, usually to treat vascular headache. It is highly toxic and in large, repeated doses can produce all the symptoms of ergot poisoning. A selective and sensitive method, based on liquid chromatography-tandem mass spectrometry (LC-MS2), has been developed for quantifying ergotamine in biological fluids with use of a quick and easy sample preparation. Ergotamine and the internal standard, trideuterated lysergic acid diethylamide, were extracted from human urine, blood, and hair by means of liquid-liquid extraction at alkaline pH. Gradient elution on a cyanopropyl column was used for chromatographic separation. Positive ion electrospray ionization and tandem mass spectrometry determination by collision-induced dissociation were performed in an ion trap mass spectrometer. The method was validated and successfully applied to a case of iatrogenic ergotism resulting from the intake of ergotamine tartrate for treating headache. For the first time, ergotamine was identified and quantified in hair. The ergotamine concentrations measured were 320 pg/mL in blood, 100 pg/mL in urine, 24 pg/mg in proximal hair, and 15 pg/mg in distal hair.

Multi-residue method for the determination of basic/neutral pharmaceuticals and illicit drugs in surface water by solid-phase extraction and ultra performance liquid chromatography–positive electrospray ionisation tandem mass spectrometry

The paper presents the development and validation of a new multi-residue method for the determination of 28 basic/neutral pharmaceuticals (antiepileptics, antibacterial drugs, β-blockers, analgesics, lipid-regulating agents, bronchodilators, histamine-2-blockers, anti-inflammatory agents, calcium channel blockers, angiotensin-II antagonists and antidepressants) and illicit drugs in surface water with the usage of a new technique: ultra performance liquid chromatography–positive electrospray tandem mass spectrometry (UPLC–MS/MS). The usage of the novel UPLC system with 1.7 μm particle size and 1 mm internal diameter column allowed for low mobile phase flow rates (0.07 mL min −1) and short retention times (from 1.3 to 15.5 min) for all compounds analysed. As a result, a fast and cost-effective method was developed. SPE with the usage of Oasis MCX strong cation-exchange mixed-mode polymeric sorbent was chosen for pharmaceuticals extraction from environmental samples. The influence of matrix-assisted ion suppression and low SPE recovery on the sensitivity of the method was studied. The instrumental limits of quantification varied from 0.2 to 10 μg L −1. The method limits of quantification were at low nanogram per litre levels and ranged from 0.3 to 50 ng L −1. The instrumental and method intra- and inter-day repeatabilities were on average less than 10%. The method was applied for the determination of pharmaceuticals in Rivers Taff (UK) and Warta (Poland). Fifteen compounds were determined in river water at levels ranging from single nanograms to single micrograms per litre.