Extraction-liquid Chromatography-tandem Mass Spectrometry Method Research Articles

Determination of vancomycin in plasma with a magnetite amino silica adsorbent prepared from rice husks and high-performance liquid chromatography—tandem mass spectrometry (HPLC-MS/MS)

A rapid and simple magnetic solid phase extraction-liquid chromatography-tandem mass spectrometry method is reported to determine vancomycin in human plasma. The Fe3O4@SiO2 nanocomposite was prepared using silica nanoparticles obtained from rice husk waste and its modification using ammonia solution to obtain a Fe3O4@SiO2-NH2 nanohybrid as a new sorbent. The structure and morphology of the sorbent were characterized by X-ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy. The nanosorbent was successfully used in magnetic solid phase extraction without hazardous solvents in 9 min with analysis by high-performance liquid chromatography – tandem mass spectrometry. Under the optimized conditions, the method provided a linear range from 10 to 1000 ng mL−1. The intra-day (n = 3) and inter-day precision (n = 3 working days) were below 10% relative standard deviation. The developed procedure was employed for determining vancomycin in human plasma with recoveries from 84.0 to 109.5% for spiked samples.

Estimation of the psychoactive substances consumption within 12 wastewater treatment plants service areas in a certain city of Guangxi, China applying wastewater-based epidemiology.

The abuse of psychoactive substances has been increasing dramatically over the last few years, which is becoming a concern for human health and social stability. How to accurately estimate psychoactive substances' total consumption in certain areas is the key to manage such substances. In order to control psychoactive substances, 8 psychoactive substances' consumption within 12 wastewater treatment plants (WWTPs) service areas in a certain city of Guangxi, China was investigated in 2019. Firstly, a solid-phase extraction-liquid chromatography-tandem mass spectrometry method was used to determine the influent concentrations. Morphine (MOR), 3, 4-methylenedioxymethamphetamine (MDMA), methamphetamine (METH), ketamine (KET), and norketamine (NK) were detected, with the concentrations ranging from less than method detection limit (NK, MDMA) to 170.91 (METH) ng/L. Then, the back-estimation of consumption was conducted according to the objective and near real-time wastewater-based epidemiology (WBE). The results demonstrate that KET, MOR, and METH are the most abused psychoactive substances, with the mean consumption of 682.42, 167.81, and 44.56mg/day/1000inh, respectively. The psychoactive substance residues of WWTPs influent were analyzed to estimate such substances' consumption in specific areas, so as to provide support for risk prevention and control.

Occurrence of Antibiotics in Influent and Effluent from 3 Major Wastewater-Treatment Plants in Finland.

Wastewater-treatment plants (WWTPs) are regarded as one of the main sources of antibiotics in the environment. In the present study, the concentrations of multiple antibiotics and their metabolites belonging to 5 antibiotic classes were determined in 3 major Finnish WWTPs. An online solid phase extraction-liquid chromatography-tandem mass spectrometry method was used for the extraction and analysis of the compounds. The method was fully validated using real and synthetic wastewaters. Seven antibiotics and 3 metabolites were found in the analyzed samples. Sulfonamides were removed most efficiently, whereas macrolides usually showed negative removal efficiency during the treatment, which means that the concentrations for individual antibiotics determined in the effluent samples were higher than in the influent samples. Sulfadiazine was found at concentrations up to 1018 ng/L, which was the highest concentration of any of the detected antibiotics in influent. In the effluent samples, the highest mean concentration was found for trimethoprim (532 ng/L). The measured mass loads of the antibiotics and metabolites to the receiving waters ranged from 2 to 157 mg/d per 1000 population equivalent. The evaluated environmental risk assessment showed that clarithromycin and erythromycin might pose a risk to the environment. The present study further underlines the importance of implementing technology for efficient removal of xenobiotics during wastewater treatment. Environ Toxicol Chem 2020;39:1774-1789. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Fatalities associated with NPS stimulants in the Greater Cologne area.

This study centres on the prevalence of new psychoactive substances (NPS) stimulant use, and its relevance as a cause of death amongst individuals between the ages of 12 and 35 in the greater Cologne area. An automated solid-phase extraction-liquid chromatography-tandem mass spectrometry method was developed for the determination of 97 stimulants in urine (including conventional stimulants, e.g. amphetamine and MDMA), of which 68 analytes were fully validated for quantification. Samples of urine or kidney tissue (in cases where urine was unavailable) of 268 deceased were collected, during autopsy, between January 2011 and May 2017 and analyzed. Blood (if available) was also investigated in cases where urine/kidney samples were tested positive for NPS. An intake of stimulants (including NPS stimulants) was proven in 50 cases. In 33 cases, only conventional stimulants were detected. A total of 17 cases were tested positive for NPS. Of the 17 NPS-positive cases, 13 were also tested positive for other conventional drugs of abuse (mostly amphetamine and MDMA). In six NPS-positive cases, at least three different NPS were proven to be ingested. Due to the determined blood concentrations, NPS was assigned as the leading cause of death, or of toxicological relevance, in the cause of death in only 5 cases. In two of the cases, NPS was judged to be a component of a multidrug poisoning, but of minor relevance.

Solid-phase extraction-liquid chromatography-tandem mass spectrometry method for the qualitative analysis of 61 synthetic cannabinoid metabolites in urine.

This article comprises the development and validation of a protocol for the qualitative analysis of 61 phase I synthetic cannabinoid metabolites in urine originating from 29 synthetic cannabinoids, combining solid-phase extraction (SPE) utilizing a reversed phase silica-based sorbent (phenyl) with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Validation was performed according to the guidelines of the German Society of Toxicological and Forensic Chemistry. Sufficient chromatographic separation was achieved within a total runtime of 12.3minutes. Validation included specificity and selectivity, limit of detection (LOD), recovery and matrix effects, as well as auto-sampler stability of processed urine samples. LOD ranged between 0.025ng/mL and 0.5ng/mL in urine. Recovery ranged between 43% and 97%, with only two analytes exhibiting recoveries below 50%. However, for those two analytes, the LODs were 0.05ng/mL in urine. In addition, matrix effects between 81% and 185% were determined, whereby matrix effects over 125% were observed for 10 non-first-generation synthetic cannabinoid metabolites. The developed method enables the rapid and sensitive detection of synthetic cannabinoid metabolites in urine, complementing the spectrum of existing analytical tools in forensic case work. Finally, application to 61 urine samples from both routine and autopsy case work yielded one urine sample that tested positive for ADB-PINACA N-pentanoic acid.

Development and validation of a high-throughput online solid-phase extraction-liquid chromatography-tandem mass spectrometry method for the detection of gonyautoxins 1&4 and gonyautoxins 2&3 in human urine.

Paralytic shellfish toxins (PSTs), including gonyautoxins and saxitoxins, are produced by multiple species of microalgae and dinoflagellates, and are bioaccumulated by shellfish and other animals. Human exposure to PSTs typically occurs through ingestion of recreationally harvested contaminated shellfish and results in nonspecific symptomology. Confirmation of exposure to PSTs has often relied on the measurement of saxitoxin, the most toxic congener; however, gonyautoxins (GTXs), the sulfated carbamate derivatives of saxitoxin, may be present in shellfish at higher concentrations. To improve identification of PST exposures, our group has developed an online solid phase extraction hydrophilic interaction liquid chromatography method to identify GTX1-4 in human urine with tandem mass spectrometry. The reportable range varied for each analyte, with all falling within 0.899 and 250 ng/mL in urine with precision <15% and >85% accuracy as determined for all quality control samples. This new online method quantitates GTX1-4 following exposures to PSTs, supporting the work of public health authorities.

Wastewater-Based Epidemiology as a New Tool for Estimating Population Exposure to Phthalate Plasticizers.

This study proposes the monitoring of phthalate metabolites in wastewater as a nonintrusive and economic alternative to urine analysis for estimating human exposure to phthalates. To this end, a solid-phase extraction-liquid chromatography-tandem mass spectrometry method was developed, allowing for the determination of eight phthalate metabolites in wastewater (limits of quantification between 0.5 and 32 ng L-1). The analysis of samples from the NW region of Spain showed that these substances occur in raw wastewater up to ca. 1.6 μg L-1 and in treated wastewater up to ca. 1 μg L-1. Concentrations in raw wastewater were converted into levels of exposure to six phthalate diesters. For two of them, these levels were always below the daily exposure thresholds recommended by the U.S. Environmental Protection Agency and the European Food Safety Authority. For the other four, however, estimates of exposure surpassed such a threshold (especially the toddler threshold) in some cases, highlighting the significance of the exposure to phthalates in children. Finally, concentrations in wastewater were also used to estimate metabolite concentrations in urine, providing a reasonable concordance between our results and the data obtained in two previous biomonitoring studies.

An on-line solid phase extraction-liquid chromatography-tandem mass spectrometry method for the determination of perfluoroalkyl acids in drinking and surface waters.

An UHPLC-MS/MS multiresidue method based on an on-line solid phase extraction (SPE) procedure was developed for the simultaneous determination of 9 perfluorinated carboxylates (from 4 to 12 carbon atoms) and 3 perfluorinated sulphonates (from 4 to 8 carbon atoms). This work proposes using an on-line solid phase extraction before chromatographic separation and analysis to replace traditional methods of off-line SPE before direct injection to LC-MS/MS. Manual sample preparation was reduced to sample centrifugation and acidification, thus eliminating several procedural errors and significantly reducing time-consuming and costs. Ionization suppression between target perfluorinated analytes and their coeluting SIL-IS were detected for homologues with a number of carbon atoms less than 9, but the quantitation was not affected. Total matrix effect corrected by SIL-IS, inclusive of extraction efficacy, and of ionization efficiency, ranged between −34 and +39%. The percentage of recoveries, between 76 and 134%, calculated in different matrices (tap water and rivers impacted by different pollutions) was generally satisfactory. LODs and LOQs of this on-line SPE method, which also incorporate recovery losses, ranged from 0.2 to 5.0 ng/L and from 1 to 20 ng/L, respectively. Validated on-line SPE-LC/MS/MS method has been applied in a wide survey for the determination of perfluoroalkyl acids in Italian surface and ground waters.

Development and validation of a high-throughput double solid phase extraction–liquid chromatography–tandem mass spectrometry method for the determination of tetrodotoxin in human urine and plasma

A sensitive analytical method for the determination of tetrodotoxin (TTX) in urine and plasma matrices was developed using double solid phase extraction (C18 and hydrophilic interaction liquid chromatography) and subsequent analysis by HPLC coupled with tandem mass spectrometry. The double SPE sample cleanup efficiently reduced matrix and ion suppression effects. Together with the use of ion pair reagent in the mobile phase, isocratic elution became possible which enabled a shorter analysis time of 5.5 min per sample. The assay results were linear up to 500 ng mL −1 for urine and 20 ng mL −1 for plasma. The limit of detection and limit of quantification were 0.13 ng mL −1 and 2.5 ng mL −1, respectively, for both biological matrices. Recoveries were in the range of 75–81%. To eliminate the effect of dehydration and variations in urinary output, urinary creatinine-adjustment was made. TTX was quantified in eight urine samples and seven plasma samples from eight patients suspected of having TTX poisoning. TTX was detected in all urine samples, with concentrations ranging from 17.6 to 460.5 ng mL −1, but was not detected in any of the plasma samples. The creatinine-adjusted TTX concentration in urine (ranging from 7.4 to 41.1 ng μmol −1 creatinine) correlated well with the degree of poisoning as observed from clinical symptoms.

An online solid-phase extraction–liquid chromatography–tandem mass spectrometry method to study the presence of thyronamines in plasma and tissue and their putative conversion from 13C6-thyroxine

Thyronamines are exciting new players at the crossroads of thyroidology and metabolism. Here, we report the development of a method to measure 3-iodothyronamine (T(1)AM) and thyronamine (T(0)AM) in plasma and tissue samples. The detection limit of the method was 0.25 nmol/l in plasma and 0.30 pmol/g in tissue both for T(1)AM and for T(0)AM. Using this method, we were able to demonstrate T(1)AM and T(0)AM in plasma and liver from rats treated with synthetic thyronamines. Although we demonstrated the in vivo conversion of (13)C(6)-thyroxine ((13)C(6)-T(4)) to (13)C(6)-3,5,3'-triiodothyronine, we did not detect (13)C(6)-T(1)AM in plasma or brain samples of rats treated with (13)C(6)-T(4). Surprisingly, our method did not detect any endogenous T(1)AM or T(0)AM in plasma from vehicle-treated rats, nor in human plasma or thyroid tissue. Although we are cautious to draw general conclusions from these negative findings and in spite of the fact that insufficient sensitivity of the method related to extractability and stability of T(0)AM cannot be completely excluded at this point, our findings raise questions on the biosynthetic pathways and concentrations of endogenous T(1)AM and T(0)AM.

Development and validation of a high-throughput zwitterionic hydrophilic interaction liquid chromatography solid-phase extraction–liquid chromatography–tandem mass spectrometry method for determination of the anti-influenza drug peramivir in plasma

An assay for the analysis for the quantification of the anti-influenza drug peramivir in human plasma using high-throughput zwitterionic (ZIC) hydrophilic interaction liquid chromatography (HILIC) solid-phase extraction (SPE) in a 96-wellplate format and liquid chromatography coupled to positive tandem mass spectroscopy has been developed and validated. The ZIC-HILIC SPE efficiently removed sources of interference present in the supernatant after protein precipitation of plasma proteins. The main advantage of the ZIC-HILIC SPE sample preparation step was that it allowed load and elution conditions to be optimised to extract only peramivir and minimize co-extraction of lipophilic phospholipids. The method was validated according to published US Food and Drugs Administration guidelines and showed excellent performance. The assay was validated over two calibration ranges (0.952–500 and 50–50,000 ng/mL) to support analysis of peramivir after intra-venous administration. The lower limit of quantification for peramivir in plasma was 1 ng/mL and the upper limit of quantification was 50,000 ng/mL. The within-day and between-day precisions expressed as RSD, were lower than 8% at all tested quality control concentrations and below 11% at the lower limit of quantification. Validation of over-curve samples ensured that it would be possible with dilution if samples went outside the calibration range.

High-throughput on-line solid-phase extraction–liquid chromatography–tandem mass spectrometry method for the simultaneous analysis of 14 antidepressants and their metabolites in plasma

A rapid, sensitive and fully automated on-line solid-phase extraction–liquid chromatography–tandem mass spectrometry (SPE–LC–MS/MS) method was developed and validated for the direct analysis of 14 antidepressants and their metabolites in plasma. Integration of the sample extraction and LC separation into a single system permitted direct injection of the plasma without prior sample pre-treatment. The applied gradient ensured the elution of all the examined drugs within 14 min and produced chromatographic peaks of acceptable symmetry. The total process time was 20 min and only 50 μL of plasma was required. Selectivity of the method was achieved by a combination of retention time and two precursor-product ion transitions for the non-deuterated compounds. The use of SPE was demonstrated to be highly effective and led to significant decreases in the interferences present in the matrix. Extraction was found to be both reproducible and efficient with recoveries >99% for all the analytes. The method showed excellent intra-assay and inter-assay precision (relative standard deviation (RSD) and bias <20%) for quality control (QC) samples spiked at a concentration of 40, 200 and 800 μg/L and the r 2 > 0.99 over the range investigated (10–1000 μg/L). Limits of quantification (LOQs) were estimated to be 10 μg/L. Furthermore, the processed samples were demonstrated to be stable for at least 48 h, except for clomipramine and norclomipramine, where a slight negative trend was observed, but did not compromise the quantification. The method was subsequently applied to authentic samples previously screened by a routine HPLC method with diode array detection (DAD).

Generic solid phase extraction–liquid chromatography–tandem mass spectrometry method for fast determination of drugs in biological fluids

A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE–LC–MS/MS). The individual components of the SPE–LC–MS/MS system were optimized in an integrated approach to maximize the application range and minimize the method development time. The optimized generic SPE–LC–MS/MS protocol was evaluated for 11 drugs with different physicochemical properties. Good quantification for 10 out of 11 of the pharmaceuticals in serum or plasma could be readily achieved. The quantitative assays gave recoveries better than 95%, lower quantification limits of 0.2–2.0 ng/ml, acceptable precision and accuracy and good linearity over 2–4 orders of magnitude. Carry-over was determined to be in the range of 0.02–0.10%, without optimization.

An on-line solid phase extraction—Liquid chromatography—Tandem mass spectrometry method for the analysis of citalopram, fluvoxamine, and paroxetine in human plasma

A specific and sensitive direct-injection high performance liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry (HPLC-APCI-MS-MS) method has been developed for the rapid identification and quantitative determination of citalopram, fluvoxamine, and paroxetine in human plasma. After dilution with 0.1% formic acid, plasma samples were injected into the LC-MS-MS system. Proteins and other large biomolecules were removed during an on-line sample cleanup step. The inter- and intra-assay coefficients of variation for all compounds were <11%. The total analysis time was 6 min per sample. The proposed method permits direct analysis of plasma samples without time-consuming sample preparation.