共查询到20条相似文献,搜索用时 31 毫秒
1.
The quantification of illicit drug and pharmaceutical residues in sewage has been shown to be a valuable tool that complements existing approaches in monitoring the patterns and trends of drug use. The present work delineates the development of a novel analytical tool and dynamic workflow for the analysis of a wide range of substances in sewage-based samples. The validated method can simultaneously quantify 51 target psychoactive substances and pharmaceuticals in sewage-based samples using an off-line automated solid phase extraction (SPE-DEX) method, using Oasis HLB disks, followed by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) in MSe. Quantification and matrix effect corrections were overcome with the use of 25 isotopic labeled internal standards (ILIS). Recoveries were generally greater than 60% and the limits of quantification were in the low nanogram-per-liter range (0.4–187 ng L−1). The emergence of new psychoactive substances (NPS) on the drug scene poses a specific analytical challenge since their market is highly dynamic with new compounds continuously entering the market. Suspect screening using high-resolution mass spectrometry (HRMS) simultaneously allowed the unequivocal identification of NPS based on a mass accuracy criteria of 5 ppm (of the molecular ion and at least two fragments) and retention time (2.5% tolerance) using the UNIFI screening platform. Applying MSe data against a suspect screening database of over 1000 drugs and metabolites, this method becomes a broad and reliable tool to detect and confirm NPS occurrence. This was demonstrated through the HRMS analysis of three different sewage-based sample types; influent wastewater, passive sampler extracts and pooled urine samples resulting in the concurrent quantification of known psychoactive substances and the identification of NPS and pharmaceuticals. 相似文献
2.
The opioid tilidine is a prodrug which is hepatically metabolized to active nortilidine and bisnortilidine. Due to the increasing
abuse of tilidine by drug users and the lack of a specific immunoassay, we developed an analytical method for the quantification
of tilidine, nortilidine, and bisnortilidine in urine suitable for screening. In a following step, this method was used to
establish data on excretion kinetics of the substances in order to evaluate the time window of detection after a single oral
dose of tilidine/naloxone and also was applied to authentic urine samples from correctional facilities. Urine samples were
mixed with internal standard solution and extracted on a weak cation exchanger at pH 6 using a Symbiosis Pico system. The
chromatographic separation was achieved within a 3.5-min run time on a Phenylhexyl column (50 × 2.0 mm, 5 μm) via gradient
elution (methanol and 0.2% formic acid) at a flow rate of 0.50 mL/min. The ESI-MS/MS was performed on a QTrap 3,200 in positive
multiple reaction monitoring mode using two mass transitions per analyte. Validating the method resulted in a lower limit
of quantification of 1.0 μg/L followed by a linear calibration range to 100 μg/L for each analyte (r
2 > 0.99). The analytical method allowed the detection of a single dose of a commercially available tilidine solution up to
7 days after administration. Using this highly sensitive method, 55 of 3,665 urine samples were tested positive. 相似文献
3.
Kuwayama K Tsujikawa K Miyaguchi H Kanamori T Iwata YT Inoue H 《Analytical and bioanalytical chemistry》2012,402(3):1257-1267
Rapid and precise identification of toxic substances is necessary for urgent diagnosis and treatment of poisoning cases and
for establishing the cause of death in postmortem examinations. However, identification of compounds in biological samples
using gas chromatography and liquid chromatography coupled with mass spectrometry entails time-consuming and labor-intensive
sample preparations. In this study, we examined a simple preparation and highly sensitive analysis of drugs in biological
samples such as urine, plasma, and organs using thin-layer chromatography coupled with matrix-assisted laser desorption/ionization
mass spectrometry (TLC/MALDI/MS). When the urine containing 3,4-methylenedioxymethamphetamine (MDMA) without sample dilution
was spotted on a thin-layer chromatography (TLC) plate and was analyzed by TLC/MALDI/MS, the detection limit of the MDMA spot
was 0.05 ng/spot. The value was the same as that in aqueous solution spotted on a stainless steel plate. All the 11 psychotropic
compounds tested (MDMA, 4-hydroxy-3-methoxymethamphetamine, 3,4-methylenedioxyamphetamine, methamphetamine, p-hydroxymethamphetamine, amphetamine, ketamine, caffeine, chlorpromazine, triazolam, and morphine) on a TLC plate were detected
at levels of 0.05 − 5 ng, and the type (layer thickness and fluorescence) of TLC plate did not affect detection sensitivity.
In addition, when rat liver homogenate obtained after MDMA administration (10 mg/kg) was spotted on a TLC plate, MDMA and
its main metabolites were identified using TLC/MALDI/MS, and the spots on a TLC plate were visualized by MALDI/imaging MS.
The total analytical time from spotting of intact biological samples to the output of analytical results was within 30 min.
TLC/MALDI/MS enabled rapid, simple, and highly sensitive analysis of drugs from intact biological samples and crude extracts.
Accordingly, this method could be applied to rapid drug screening and precise identification of toxic substances in poisoning
cases and postmortem examinations. 相似文献
4.
Katarzyna Pauter Małgorzata Szultka-Młyńska Michał Szumski Anna Król-Górniak Paweł Pomastowski Bogusław Buszewski 《Electrophoresis》2022,43(9-10):978-989
In this study, a new analytical method was developed and validated for the simultaneous analysis of antibiotic drugs (amoxicillin, cefotaxime, ciprofloxacin, clindamycin, linezolid, metronidazole) and their metabolites (amoxycilloic acid, amoxicillin diketopiperazine, 3-desacetyl cefotaxime lactone, clindamycin sulfoxide, ciprofloxacin piperazinyl-N4-sulfate, linezolid N-oxide, metronidazole-OH) in human urine. Capillary electrophoresis (CE) along with the tandem mass spectrometry (MS/MS) was used to determine and identify all analytes. Appropriate conditions for MS/MS measurements along with the use of the central composite design were optimized. The effects of different analytical conditions (the composition, the concentration, and the pH value of the background electrolyte, the time and pressure of the injection, the capillary temperature and influence of the organic modifier) on the migration and separation of antibiotic drugs and metabolites were examined using the CE-DAD. The analytical procedure was linear for concentrations ranging from 20 to 1000 ng/mL, with determination coefficients higher than 0.99 for all the analytes. The validated analytical procedure was then applied to the measurement of antibiotic drugs and their metabolites in human urine samples. 相似文献
5.
Gerace E Salomone A Fasano F Costa R Boschi D Di Stilo A Vincenti M 《Analytical and bioanalytical chemistry》2011,400(1):137-144
Selective androgen receptor modulators (SARMs) represent an emerging class of drugs likely to be abused in sport. For clinical
applications, these substances provide a promising alternative to testosterone-replacement therapies and their advantages
include oral bioavailability, androgen receptor specificity, tissue selectivity, and the absence of steroid-related side effects.
Although not yet commercially available, since January 2008 SARMs have been included on the prohibited list issued yearly
by the World Anti-Doping Agency (WADA), so control laboratories need to update their procedures to detect either the parent
drugs or their metabolites. Within this context, two quinolinone SARM models were synthesized and automatically characterized
to update the existing routine screening procedures. The conditions for the new target analytes are compatible with the existing
laboratory protocols used for both in-competition and out-of-competition controls and can be included in them. Validation
parameters according to ISO 17025 and WADA guidelines were successfully determined. For analytical determinations, spiked
urine samples were hydrolyzed and extracted at pH 9.6 with 10 mL of tert-butyl methyl ether. Then, the analytes were subsequently converted into trimethylsilyl derivatives and detected by gas chromatography–mass
spectrometry. The absence of interferents, together with excellent repeatability of both retention times and the relative
abundances of diagnostic ions, allowed proper identification of all SARM analytes. The analytes’ quantification was linear
up to 500 ng/mL and precision criteria were satisfied (coefficient of variation less than 25% at 10 ng/mL). The limits of
detection were 1 ng/mL for both SARMs, whereas recovery values were between 95.5 and 99.3%. The validated method can be efficiently
used for urine screening of the 2-quinolinone-derived SARMs tested. 相似文献
6.
This paper presents a general screening method, based on liquid chromatography/mass spectrometry (LC/MS), for the simultaneous
detection in human urine of 72 xenobiotics (21 diuretics, 16 synthetic glucocorticoids, 17 beta-adrenergic drugs, 10 stimulants,
5 anti-oestrogens and 3 anabolic steroids), excreted free or as glucuro-conjugates in urine. Although the method has been
specifically designed and evaluated in view of its potential application to anti-doping analyses, it can also be effective
in other areas of analytical toxicology. Sample preparation was based on two liquid/liquid separation steps (performed at
alkaline and at acid pH, respectively) of hydrolyzed human urine, and then an assay by LC/MS-MS in positive and negative ionization
mode using an electrospray ionization source (ESI) and multiple reaction monitoring (MRM) as the acquisition mode. The overall
time needed for an LC run was less than 15 minutes. All compounds showed good reproducibility in terms of both the retention
times (CV%<1) and the relative abundances of the diagnostic transitions (CV%<10). The limits of detection (LOD) were in the
range of 1–50 ng/mL for glucocorticoids, anti-oestrogens and steroids, and 50–500 ng/mL for diuretics, beta-adrenergic drugs
and stimulants, thus satisfying the minimum required performance limits (MRPL) set by the World Anti-Doping Agency (WADA)
for the accredited anti-doping laboratories. 相似文献
7.
Boroujerdi AF Lee PA DiTullio GR Janech MG Vied SB Bearden DW 《Analytical and bioanalytical chemistry》2012,403(3):777-784
In-line solid-phase extraction–capillary electrophoresis coupled with mass spectrometric detection (SPE–CE–MS) has been used
for determination of 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), codeine (COD), hydrocodeine (HCOD), and 6-acetylmorphine
(6AM) in urine. The preconcentration system consists of a small capillary filled with Oasis HLB sorbent and inserted into
the inlet section of the electrophoresis capillary. The SPE–CE–MS experimental conditions were optimized as follows: the sample
(adjusted to pH 6.0) was loaded at 930 mbar for 60 min, elution was performed with methanol at 50 mbar for 35 s, 60 mmol L−1 ammonium acetate at pH 3.8 was used as running buffer, the separation voltage was 30 kV, and the sheath liquid at a flow
rate of 5.0 μL min−1 was isopropanol–water 50:50 (v/v) containing 0.5% acetic acid. Analysis of urine samples spiked with the four drugs and diluted 1:1 (v/v) was studied in the linear range 0.08–10 ng mL−1. Detection limits (LODs) (S/N = 3) were between 0.013 and 0.210 ng mL−1. Repeatability (expressed as relative standard deviation) was below 7.2%. The method developed enables simple and effective
determination of these drugs of abuse in urine samples at the levels encountered in toxicology and doping. 相似文献
8.
A weak cation-exchange monolithic column has been prepared in stainless steel tubing and used as the solid-phase extraction
material in quantitative analysis of caffeine and theophylline in urine. Column switching, with water as mobile phase, was
used for on-line cleaning and screening of human urine samples. Reversed-phase high-performance liquid chromatography was
then performed on a C18 column with methanol–water 30:70 (v/v) as mobile phase at a flow rate of 0.5 mL min−1. Ultraviolet detection was performed at 274 nm. Good linear relationships were obtained between response and concentrations
of caffeine and theophylline in the range 0.1–50 μg mL−1. Absolute recovery ranged from 77.4 to 82.3% and inter-day and intra-day relative standard deviations were less than 5%.
The method was suitable for analysis of caffeine and theophylline in human urine, because it eliminated tedious pretreatment
and enabled rapid, economic, repeatable, and effective assay of traces of the drugs in biological samples. 相似文献
9.
《Electrophoresis》2017,38(13-14):1800-1805
Fast, simple, and accurate CE method enabling determination of lipoic acid (LA) in human urine has been developed and validated. LA is a disulfide‐containing natural compound absorbed from the organism's diet. Due to powerful antioxidant activity, LA has been used for prevention and treatment of various diseases and disorders, e.g. cardiovascular diseases, neurodegenerative disorders, and cancer. The proposed analytical procedure consists of liquid–liquid sample extraction, reduction of LA with tris(2‐carboxyethyl)phosphine, derivatization with 1‐benzyl‐2‐chloropyridinium bromide (BCPB) followed by field amplified sample injection stacking, capillary zone electrophoresis separation, and ultraviolet‐absorbance detection of LA‐BCPB derivative at 322 nm. Effective baseline electrophoretic separation was achieved within 6 min under the separation voltage of 20 kV (∼80 μA) using a standard fused‐silica capillary (effective length 51.5 cm, 75 μm id) and BGE consisted of 0.05 mol/L borate buffer adjusted to pH 9. The experimentally determined limit of detection for LA in urine was 1.2 μmol/L. The calibration curve obtained for LA in urine showed linearity in the range 2.5–80 μmol/L, with R 2 0.9998. The relative standard deviation of the points of the calibration curve was lower than 10%. The analytical procedure was successfully applied to analysis of real urine samples from seven healthy volunteers who received single 100 mg dose of LA. 相似文献
10.
Hossein Salar Amoli Yadollah Yamini Hossein Darmani 《Journal of separation science》2020,43(13):2636-2645
A novel solid‐phase microextraction fiber was synthesized by coating a stainless steel wire with polyoxomolybdate368/polyaniline as a sorbent aimed at extraction of amitriptyline, nortriptyline, and doxepin as antidepressant drugs from urine and blood samples. The polyoxomolybdate368/polyaniline composite coating was applied using electropolymerization process under constant potential. This composition leads to enhanced extraction efficiency of the fiber. Scanning electron microscopy images show that huge three‐dimensional structures of polyoxomolybdate368 in composite induced more non‐smooth and porous fiber. In order to optimize of the extraction process, a series of variables including concentration of the composite materials, coating thickness, pH, extraction time, salt addition, and stirring rate was investigated and optimum conditions were determined. Analysis of surface morphology and chemical composition was performed. High‐performance liquid chromatography was used for separation and evaluation of mentioned antidepressant drugs from the matrixes. The experiments indicated a detection limits of <0.2 ng/L and a linear dynamic range of 0.3–100 ng/L (R2 > 0.994). The relative recovery values were found to be in the range of 92–98%. It was concluded that the purposed fiber is highly efficient in analyzing traces of antidepressant drugs in urine and blood. 相似文献
11.
《Journal of mass spectrometry : JMS》2017,52(8):ii-ii
The influx of new psychoactive substances (NPS) has created a need for improved methods for drug testing in toxicology laboratories. The aim of this work was to design, validate and apply a multi‐analyte liquid chromatography–high‐resolution mass spectrometry (LC–HRMS) method for screening of 148 target analytes belonging to the NPS class, plant alkaloids and new psychoactive therapeutic drugs. The analytical method used a fivefold dilution of urine with nine deuterated internal standards and injection of 2 μl. The LC system involved a 2.0 μm 100 × 2.0 mm YMC‐UltraHT Hydrosphere‐C18 column and gradient elution with a flow rate of 0.5 ml/min and a total analysis time of 6.0 min. Solvent A consisted of 10 mmol/l ammonium formate and 0.005% formic acid, pH 4.8, and Solvent B was methanol with 10 mmol/l ammonium formate and 0.005% formic acid. The HRMS (Q Exactive, Thermo Scientific) used a heated electrospray interface and was operated in positive mode with 70 000 resolution. The scan range was 100–650 Da, and data for extracted ion chromatograms used ± 10 ppm tolerance. Product ion monitoring was applied for confirmation analysis and for some selected analytes also for screening. Method validation demonstrated limited influence from urine matrix, linear response within the measuring range (typically 0.1–1.0 μg/ml) and acceptable imprecision in quantification (CV <15%). A few analytes were found to be unstable in urine upon storage. The method was successfully applied for routine drug testing of 17 936 unknown samples, of which 2715 (15%) contained 52 of the 148 analytes. It is concluded that the method design based on simple dilution of urine and using LC–HRMS in extracted ion chromatogram mode may offer an analytical system for urine drug testing that fulfils the requirement of a ‘black box’ solution and can replace immunochemical screening applied on autoanalyzers. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
12.
Saito T Fukushima T Yui Y Miyazaki S Nakamoto A Namera A Inokuchi S 《Analytical and bioanalytical chemistry》2011,400(1):25-31
We present a method based on monolitic spin column extraction and gas chromatography–mass spectrometry as an analytical method
for screening diquat (DQ), paraquat (PQ), and fenitrothion in serum and urine. This method is useful for clinical and forensic
toxicological analyses. Recovery of DQ, PQ, and fenitrothion from serum and urine, spiked at concentrations between 0.1, 2.5,
20, and 45 μg/ml, ranged from 51.3% to 106.1%. Relative standard deviation percentages were between 3.3% and 14.8%. Detection
and quantitation limits for serum and urine were 0.025 and 0.05 μg/ml, respectively, for DQ, 0.1 and 0.1 μg/ml, respectively,
for PQ, and 0.025 and 0.05 μg/ml, respectively, for fenitrothion. Therefore, these compounds can be detected and quantified
in the case of acute poisoning. 相似文献
13.
Alaa S. Abd‐El‐Aziz Amani A. Abdelghani Ebtehal G. El‐Ghezlani Doaa Abou El‐ezz Laila H. Abdel‐Rahman 《Macromolecular bioscience》2021,21(1)
The synthesis of a novel and attractive class of nonsteroidal anti‐inflammatory and antimicrobial organoiron dendrimers attached to the well‐known drug ibuprofen is achieved. The structures of these dendrimers are established by spectroscopic and analytical techniques. The antimicrobial activity of these dendrimers is investigated and tested against five human pathogenic Gram‐positive and Gram‐negative bacteria, and minimum inhibitory concentrations are reported. Some of these synthesized dendrimers exhibit higher inhibitory activity against methicillin‐resistant Staphylococcus aureus, vancomycin‐resistant Enterococcus faecium, and Staphylococcus warneri compare to the reference drugs. As well, the in vitro and in vivo anti‐inflammatory activities of these dendrimers are evaluated. The results of in vivo anti‐inflammatory activity and histopathology of inflamed paws show that all dendrimers display considerable anti‐inflammatory activity; however, second‐generation dendrimer ( G2‐D6 ) shows the best anti‐inflammatory activity, which is more potent than the commercial drug ibuprofen at the same tested dose. Results of the toxicity study reveal that G2‐D6 is the safest drug on biological tissues. 相似文献
14.
Camilla Montesano Manuel Sergi Mariaelena Moro Sabino Napoletano Francesco Saverio Romolo Michele Del Carlo Dario Compagnone Roberta Curini 《Journal of mass spectrometry : JMS》2013,48(1):49-59
This study describes a method for the screening of methylenedioxyamphetamine‐ and piperazine‐derived compounds in urine by liquid chromatography‐tandem mass spectrometry. These substances, characterized by possessing common moieties, are screened using precursor ion and neutral loss scan mode and then quantified in multiple reaction monitoring acquisition mode. Based on the product‐ion spectra of different known molecules, chosen as ‘model’, characteristic neutral losses and product ions were selected: piperazines were detected in precursor ion scan of m/z 44 and neutral loss of 43 and 86 while amphetamines in precursor ion scan of m/z 133, 135 and 163. The applicability of the screening approach was studied in blank urine spiked with selected analytes and processed by solid‐phase extraction. Linearity, matrix effect, precision, accuracy, limits of detection and limits of quantification were evaluated both for the screening and the quantification methods. The ability of the screening method to provide semi‐quantitative data was demonstrated. This method appears to be a useful tool for the identification of designer drugs derived from piperazines or methylenedioxyamphetamines and can be potentially applied to other drug classes. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
15.
Kikura-Hanajiri R Kawamura M Miyajima A Sunouchi M Goda Y 《Analytical and bioanalytical chemistry》2011,400(1):165-174
In order to develop an analytical method for the discrimination of dextromethorphan (an antitussive medicine) from its enantiomer,
levomethorphan (a narcotic) in biological samples, chiral analyses of these drugs and their O-demethyl and/or N-demethyl metabolites in rat plasma, urine, and hair were carried out using LC-MS/MS. After the i.p. administration of dextromethorphan
or levomethorphan to pigmented hairy male DA rats (5 mg/kg/day, 10 days), the parent compounds and their three metabolites
in plasma, urine and hair were determined using LC-MS/MS. Complete chiral separation was achieved in 12 min on a Chiral CD-Ph
column in 0.1% formic acid–acetonitrile by a linear gradient program. Most of the metabolites were detected as being the corresponding
O-demethyl and N, O-didemethyl metabolites in the rat plasma and urine after the hydrolysis of O-glucuronides, although obvious differences in the amounts of these metabolites were found between the dextro and levo forms.
No racemation was observed through O- and/or N-demethylation. In the rat hair samples collected 4 weeks after the first administration, those differences were more clearly
detected and the concentrations of the parent compounds, their O-demethyl, N-demethyl, and N, O-didemethyl metabolites were 63.4, 2.7, 25.1, and 0.7 ng/mg for the dextro forms and 24.5, 24.6, 2.6, and 0.5 ng/mg for the
levo forms, respectively. In order to fully investigate the differences of their metabolic properties between dextromethorphan
and levomethorphan, DA rat and human liver microsomes were studied. The results suggested that there might be an enantioselective
metabolism of levomethorphan, especially with regard to the O-demethylation, not only in DA rat but human liver microsomes as well. The proposed chiral analyses might be applied to human
samples and could be useful for discriminating dextromethorphan use from levomethorphan use in the field of forensic toxicology,
although further studies should be carried out using authentic human samples. 相似文献
16.
The combination of capillary electrophoresis (CE) and mass spectrometry (MS) is particularly well adapted to bioanalysis due to its high separation efficiency, selectivity, and sensitivity; its short analytical time; and its low solvent and sample consumption. For clinical and forensic toxicology, a two-step analysis is usually performed: first, a screening step for compound identification, and second, confirmation and/or accurate quantitation in cases of presumed positive results. In this study, a fast and sensitive CE-MS workflow was developed for the screening and quantitation of drugs of abuse in urine samples. A CE with a time-of-flight MS (CE-TOF/MS) screening method was developed using a simple urine dilution and on-line sample preconcentration with pH-mediated stacking. The sample stacking allowed for a high loading capacity (20.5% of the capillary length), leading to limits of detection as low as 2 ng mL−1 for drugs of abuse. Compound quantitation of positive samples was performed by CE-MS/MS with a triple quadrupole MS equipped with an adapted triple-tube sprayer and an electrospray ionization (ESI) source. The CE-ESI-MS/MS method was validated for two model compounds, cocaine (COC) and methadone (MTD), according to the Guidance of the Food and Drug Administration. The quantitative performance was evaluated for selectivity, response function, the lower limit of quantitation, trueness, precision, and accuracy. COC and MTD detection in urine samples was determined to be accurate over the range of 10–1000 ng mL−1 and 21–1000 ng mL−1, respectively. 相似文献
17.
A simple, rapid, sensitive and low‐cost method using capillary electrophoresis (CE) coupled with field‐amplified sample stacking (FASS) has been developed and validated for the simultaneous determination of strychnine and brucine residues in human urine. Before sample loading, a water plug (3.5 kPa, 3 s) was injected to contain sample cations and to permit FASS. Electrokinetic injection at a voltage (20 kV, 25 s) was then used to introduce cations. Separation was performed using 20 mM acetate buffer (pH 3.8) with an applied voltage of 20 kV. The calibration curves were linear over a range of 8.00–2.56 ∞ 102 ng/mL (r = 0.9995) for strychnine and 10.0–3.20 × 102 ng/mL (r = 0.9999) for brucine. Extraction recoveries in urine were greater than 79.6 and 82.8% for strychnine and brucine, respectively, with an RSD of less than 4.9%. The detection limits (signal‐to‐noise ratio 3) for strychnine and brucine were 2.00 and 2.50 ng/mL, respectively. A urine sample from one healthy female volunteer (26 years old, 50 kg) was pretreated and analyzed. Strychnine and brucine levels in urine could be detected 24 h after administration. On these grounds, this method was feasible for application to preliminary screening of trace levels of abused drugs for both doping control and forensic analysis. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
18.
A novel analytical approach has been developed for the determination of selected drugs (milrinone, enalapril, carvedilol, spironolactone, acenocumarol, ticlopidine, cilazapril) and their metabolites (2‐oxoticlopidine, cilazaprilat, canrenone, 5′‐hydroxycarvedilol, O‐desmethyl‐carvedilol, enalaprilat) in human urine, based on a miniaturized extraction technique; semiautomatic microextraction by packed sorbent, using a new digitally controlled syringe, followed by ultra high pressure liquid chromatography separation combined with UV detection. During method optimization, the extraction parameters as the type of sorbent material, type and volume of elution solution, number of extraction cycles, volume and pH of sample, type and volume of washing solution were studied. The chromatographic separation of the target analytes was performed with a core–shell analytical column using 0.05% trifluoroacetic acid in water and acetonitrile in gradient elution mode. The limits of quantification ranged from 0.016 to 0.045 μg/mL. Under the optimized conditions, extraction efficiency was higher than 70.1% for drugs and their metabolites. Due to its simplicity and speed, this method was successfully applied to the quantitation of selected compounds in urine samples. 相似文献
19.
M. Houshmand A. Jabbari H. Heli M. Hajjizadeh A. A. Moosavi-Movahedi 《Journal of Solid State Electrochemistry》2008,12(9):1117-1128
The electrocatalytic oxidation of aspirin and acetaminophen on nanoparticles of cobalt hydroxide electrodeposited on the surface
of a glassy carbon electrode in alkaline solution was investigated. The process of oxidation and the kinetics have been investigated
using cyclic voltammetry, chronoamperometry, and steady-state polarization measurements. Voltammetric studies have indicated
that in the presence of drugs, the anodic peak current of low valence cobalt species increases, followed by a decrease in
the corresponding cathodic current. This indicates that drugs are oxidized on the redox mediator which is immobilized on the
electrode surface via an electrocatalytic mechanism. With the use of Laviron’s equation, the values of anodic and cathodic
electron-transfer coefficients and charge-transfer rate constant for the immobilized redox species were determined as α
s,a = 0.72, α
s,c = 0.30, and k
s = 0.22 s−1. The rate constant, the electron transfer coefficient, and the diffusion coefficient involved in the electrocatalytic oxidation
of drugs were reported. It was shown that by using the modified electrode, aspirin and acetaminophen can be determined by
amperometric technique with detection limits of 1.88 × 10−6 and 1.83 × 10−6 M, respectively. By analyzing the content of acetaminophen and aspirin in bulk forms using chronoamperometric and amperometric
techniques, the analytical utility of the modified electrode was achieved. The method was also proven to be valid for analyzing
these drugs in urine samples. 相似文献
20.
Albert Prez‐Alcaraz Francesc Borrull Carme Aguilar Marta Calull 《Electrophoresis》2019,40(14):1762-1770
This work presents a strategy based on the in‐line coupling of SPE and CE for the chiral determination of cathinones (R,S‐mephedrone, R,S‐4‐methylephedrine, and R,S‐ methylenedioxypyrovalerone) in urine samples, using a sample pretreatment based on liquid‐liquid extraction. The chiral separation of the compounds is achieved by adding a mixture of 8 mM 2‐hydroxypropil β‐CD and 5 mM β‐CD to the BGE, which consists of 70 mM of monosodium phosphate aqueous solution at pH 2.5. Oasis HLB was the selected sorbent for the in‐line SPE device, and to reduce analysis time and LODs, several parameters affecting the in‐line SPE system were evaluated, such as pressure and time of sample injection and dimensions of the SPE device. The highest preconcentration factors were achieved by using 3 bar of injection pressure for 20 min with an in‐line SPE device of 2 mm length and 150 µm of i.d. The developed method was applied to determine the presence of the compounds in spiked urine samples. The LODs obtained were between 3 and 8 ng/mL, and these levels were below the usual concentrations at which these drugs are present in urine from cathinone abusers. Thus, the optimized method has the potential to be applied for toxicological and forensic purposes. 相似文献