scholarly journals Detection and Identification of Zeranol in Chicken or Rabbit Liver by Liquid Chromatography-Electrospray Tandem Mass Spectrometry

2002 ◽  
Vol 85 (4) ◽  
pp. 841-847 ◽  
Author(s):  
Xiaoming Fang ◽  
Jiahua Chen ◽  
Dehua Guo ◽  
Guoquan Wang

Abstract A sensitive, specific, and reliable liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for detection and identification of zeranol in chicken or rabbit liver. A homogenized liver sample was hydrolyzed with β-glucuronidase/arylsulfatase, and the hydrolysate was extracted with ethyl ether. The supernatant was evaporated to dryness, and the residue was dissolved in chloroform and re-extracted with sodium hydroxide. After acidification, the extract was cleaned up on a C18 solid-phase extraction cartridge and analyzed by electrospray LC-MS/MS in the negative ion mode. The multiple reaction monitoring transition from both m/z 321 to 277 and m/z 321 to 303 was monitored for confirmation, and the product ion of 277 was used for quantitation. Separation was performed on a Waters XTettra™ C18 column (50 × 2.1 mm, 3.5 μm) combined with a safeguard column (Symmetry C18, 20 × 3.9 mm, 5 μm), using a gradient elution with acetonitrile and 20mM ammonium acetate. Calibration curves were prepared and good linearity was achieved over the concentration ranges tested. For all liver samples fortified at 3 different levels of 1, 5, and 50 μg/kg, the overall recoveries and relative standard deviations were in the range of 61–90 and 8–13%, respectively. The limit of quantitation based on the assay validation was 1 μg/kg. The method had been used on a routine basis for detection and identification of zeranol in liver samples.

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 389 ◽  
Author(s):  
Xiangsheng Zhao ◽  
Shihui Zhang ◽  
Dan Liu ◽  
Meihua Yang ◽  
Jianhe Wei

Dalbergia odorifera, a traditional Chinese medicine, has been used to treat cardio- and cerebrovascular diseases in China for thousands of years. Flavonoids are major active compounds in D. odorifera. In this paper, a rapid and sensitive ultra-high performance liquid chromatography-triple quadrupole mass spectrometry method was developed and validated for simultaneous determination of 17 flavonoids in D. odorifera. Quantification was performed by multiple reaction monitoring using electrospray ionization in negative ion mode. Under the optimum conditions, calibration curves for the 17 analytes displayed good linearity (r2 > 0.9980). The intra- and inter-day precisions (relative standard deviations) were lower than 5.0%. The limit of quantitation ranged from 0.256 to 18.840 ng/mL. The mean recovery range at three spiked concentrations was 94.18–101.97%. The validated approach was successfully applied to 18 samples of D. odorifera. Large variation was observed for the contents of the 17 analytes. Sativanone and 3′-O-methylviolanone were the dominant compounds. The fragmentation behaviors of six flavonoids were investigated using UPLC with quadrupole time-of-flight tandem mass spectrometry. In negative ion electrospray ionization mass spectrometry, all the flavonoids yielded prominent [M − H]− ions. Fragments for losses of CH3, CO, and CO2 were observed in the mass spectra. Formononetin, liquiritigenin, isoliquiritigenin, sativanone, and alpinetin underwent retro-Diels–Alder fragmentations. The proposed method will be helpful for quality control of D. odorifera.


Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2616
Author(s):  
Jonghwa Lee ◽  
Byung Joon Kim ◽  
Eunhye Kim ◽  
Jeong-Han Kim

The dissipation behaviors of acetamiprid and chlorantraniliprole in kimchi cabbages were studied under open-field conditions. A simple and rapid analytical method was developed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The multiple reaction monitoring (MRM) conditions of two pesticides were optimized to quantify and identify the pesticide residues. Sample preparation was performed by the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method. Average recovery rates at the different spiked levels (0.05 and 0.25 mg/kg) were in the range of 103.6–113.9% (acetamiprid) and 80.8–91.2% (chlorantraniliprole), and the relative standard deviations were ≤4.3% for all. The dissipation kinetics were assessed using first-order equations after spraying acetamiprid and chlorantraniliprole individually on kimchi cabbages. The biological half-lives in field 1 and 2 were 5.2 and 6.3 days (acetamiprid) and 10.0 and 15.2 days (chlorantraniliprole), respectively. Based on the dissipation equations, the pre-harvest residue limits (PHRLs) corresponding to each day before harvest were suggested as the guidelines to meet the MRL on harvest day. It was also predicted that the terminal residues observed after multiple sprayings (three and seven days) would be below the MRL when harvested, in compliance with the established pre-harvest intervals.


Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3210 ◽  
Author(s):  
Michele Protti ◽  
Camilla Marasca ◽  
Marco Cirrincione ◽  
Angelo E. Sberna ◽  
Roberto Mandrioli ◽  
...  

Testing and monitoring anabolic androgenic steroids in biological fluids is a key activity in anti-doping practices. In this study, a novel approach is proposed, based on dried urine microsampling through two different workflows: dried urine spots (DUS) and volumetric absorptive microsampling (VAMS). Both techniques can overcome some common drawbacks of urine sampling, such as analyte instability and storage and transportation problems. Using an original, validated liquid chromatography–tandem mass spectrometry (LC-MS/MS) method, exogenous and endogenous unconjugated steroids were analysed. Despite the limitations of microsampling volume, good sensitivity was obtained (limit of quantitation ≤1.5 ng/mL for all analytes), with satisfactory precision (relative standard deviation <7.6%) and absolute recovery (>70.3%). Both microsampling platforms provide reliable results, in good agreement with those obtained from urine.


Author(s):  
Chu-An Yang ◽  
Hsiu-Chuan Liu ◽  
Ray H Liu ◽  
Dong-Liang Lin ◽  
Shu-Pao Wu

Abstract Abuse of new psychoactive substances (NPS) has become a health and social issue of global concern. p-Methoxyamphetamine (PMA)/p-methoxymethamphetamine (PMMA) with fluoro- or chloro-derivatives of amphetamine and methamphetamine were among the most common drugs found in specimens from fatal cases in Taiwan during the January 2011 to December 2018 period. A liquid–liquid extraction sample preparation protocol with highly sensitive ultra-high performance liquid chromatography–tandem mass spectrometry approach was developed for the simultaneous analysis of seven phenethylamine-type drugs—PMA, PMMA, p-methoxyethylamphetamine, 4-fluoroamphetamine (4-FA), 4-fluoromethamphetamine (4-FMA), 4-chloroamphetamine (4-CA) and 4-chloromethamphetamine (4-CMA)—in postmortem blood and urine specimens. Separation by liquid chromatography was performed by Agilent Zorbax SB-Aq column. Tandem mass spectrometry was operated in Agilent Jet Stream Technology electrospray ionization in positive-ion multiple reaction monitoring mode. An analytical methodology was evaluated using drug-free blood and urine after fortification with 100–2,000 ng/mL of the seven target analytes. Average extraction recoveries were &gt;80%; slightly higher ion suppression was observed for PMA and 4-CA; intra-/inter-day precision (% coefficient of variation) and accuracy were in the ranges of 0.52–12.3% and 85–110%, respectively. Limit of detection and lower limit of quantitation for these seven analytes were both in the 0.5–5 ng/mL range. Interference and carryover were not significant. This relatively simple methodology was found effective and reliable for routine identification and quantitation of these seven analytes in postmortem and antemortem blood and urine specimens received in 2018. Analytical data obtained from these actual cases indicated the following: (i) compared to findings reported during the 2007–2011 period, the use of substituted phenethylamine-type drugs decreased in 2018; (ii) ketamine and 7-aminonimetazepam (the main metabolite of nimetazepam) were the most common co-ingested substances in specimens containing PMA/PMMA, 4-FA/4-FMA, or 4-CA/4-CMA; and (iii) in drug fatalities, the concentration of PMA was significantly higher than the concentration of PMMA in both urine and blood, while the reverse was true in urine specimens from antemortem cases.


Author(s):  
BG Keevil ◽  
SJ McCann ◽  
DP Cooper ◽  
MR Morris

Background: The immunosuppressive drug tacrolimus has complex and unpredictable pharmacokinetics, therefore regular monitoring is required in patients receiving tacrolimus therapy. We have developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring tacrolimus concentrations in whole blood and have compared it with a microparticle enzyme immunoassay. Methods: For the LC-MS/MS assay, samples were prepared in a 96-deep well microtitre plate by adding 10 µL of blood to 40 µL of 0·1 mol/L zinc sulphate solution. Proteins were precipitated by adding 100 µL acetonitrile containing ascomycin internal standard. After vigorous mixing and centrifugation, 20 µL of the supernatant was injected into the LC-MS/MS system. A C18 cartridge (3 mm × 4 mm) was eluted with a step gradient of 50% to 100% methanol containing 2 mmol/L ammonium acetate and 0·1% (v/v) formic acid, at 0·6 mL/min. The column was maintained at 55°C. Results: The retention times were 0·98 min for ascomycin and 0·98 min for tacrolimus. Cycle time was 2·5 min, injection to injection. The analytes were monitored using a Quattro micro tandem mass spectrometer operated in multiple reaction monitoring mode using the following transitions: m/z821 > 768 (tacrolimus) and m/z809 > 756 (ascomycin). The limit of quantitation was 0·5 µg/L and the assay was linear up to 30 µg/L. Precision of the method, over the concentration range 2·5-15·0 µg/L, was < 7% within-batch and < 6% between-batch. Total time to analyse 24 samples including result generation was 90 min. Conclusion: We conclude that the LC-MS/MS method is quick, precise and robust and will provide a fast turn around of results for the transplant physician.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Dinh-Vu Le ◽  
Trong-Tuan Nguyen ◽  
Van-Trong Nguyen

A liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been validated for the simultaneous determination of methamphetamine (MA) and 3,4-methylenedioxy-N-methamphetamine (MDMA) in the blood sample. Under the optimal experimental conditions, the concentration of MA can be determined in the range from 1 µg/L to 5000 µg/L with the method detection limit (MDL) of 0.31 µg/L. The range from 0.5 to 500 µg/L is observed for the determination of MDMA with the MDL down to 0.25 µg/L. The practical applicability of the method is performed with the recovery ranging from 85.3% to 94% for MA and from 86.9% to 95.5% for MDMA. At the different concentrations of drugs, the relative standard deviations (RSD) for both MA and MDMA are lower than 5.7%. The method was applied to analyse 1995 blood samples that had been collected from the Forensic Medicine Centre of Ho Chi Minh City. The results showed 1.75% positive with MA and 0.25% positive with MDMA. These two drugs take 10% of the total drugs positive samples. By using deuterium-labelled methamphetamine-d5 and 3,4-methylenedioxy-N-methamphetamine-d5 as the internal standards in the determination and the use of MS/MS in multiple reaction monitoring mode signal readout, the method exhibits robustness specificity and can be applied in simultaneous determination of MA and MDMA in blood with high selectivity and sensitivity.


2021 ◽  
Vol 71 (4) ◽  
pp. 1355-59
Author(s):  
Sehrish Naz ◽  
Muhammad Aamir ◽  
Zujaja Hina Haroon ◽  
Sobia Irum Kirmani ◽  
Nisar Ahmed ◽  
...  

Objective: To evaluate a novel liquid chromatography tandem mass spectrometry based method for serum 25 hydroxy vitamin D (D2 and D3 metabolites) analysis. Study Design: Cross sectional validation study. Place and Duration of Study: Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology, Pakistan, from Mar 2019 to Mar 2020. Methodology: Samples were extracted and 25 OH vitamin-D was separated by means of chromatography and finally quantified via mass spectrometer. A quadrupole- tandem mass spectrometer with Electron spray Ionization coupled to high performance liquid chromatography was adopted for detection and quantitation of 25-hydroxyvitamin D2 and D3 in serum. Results: Limit of detection (LOD) was at the level of 2.49 ng/ml and limit of quantitation (LOQ) was estimated to be 3.9 ng/ml for both the metabolites. The correlation coefficient was 0.99. For D3 observed recovery was 98% and 97.5% respectively while for D2 the recovery was calculated to be 97% and 98%. Percentage relative standard deviation (RSD) was 0.8% and 1.3% respectively. This method has an advantage of less matrix effects, minimal cross-reactivity with 24, 25 hydroxy vit D and 25, 26 di-hydroxy vitamin D metabolite than the routinely used antibody-based assays. Conclusion: This LC-MS/MS methodology is sensitive, specific and can quantitate Vitamin D2 and D3 quite efficiently. This method may be employed for vitamin D analysis in clinical laboratories.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yan Du ◽  
Hongliang Su ◽  
Jie Cao ◽  
Zhiwen Wei ◽  
Yujin Wang ◽  
...  

Male Sprague-Dawley rats (n=18) were randomly divided into three groups: a saline group (20 mL/kg by gavage), a ketamine (KET) group (100 mg/kg by gavage), and a KET (the same routes and doses) combined with levo-tetrahydropalmatine (l-THP; 40 mg/kg by gavage) group (n=6). Blood samples were acquired at different time points after drug administration. A simple and sensitive ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established to determine the concentrations of KET and its metabolite, norketamine (NK), in rat plasma. Chromatographic separation was achieved using a BEH C18 column (2.1 mm×50 mm, 1.7 μm) with chlorpheniramine maleate (Chlor-Trimeton) as an internal standard (IS). The initial mobile phase consisted of acetonitrile–water with 0.1% methanoic acid (80 : 20, v/v). The multiple reaction monitoring (MRM) modes of m/z 238.1→m/z 179.1 for KET, m/z 224.1→m/z 207.1 for NK, and m/z 275→m/z 230 for Chlor-Trimeton (IS) were utilized to conduct a quantitative analysis. Calibration curves of KET and NK in rat plasma demonstrated good linearity in the range of 2.5–500 ng/mL (r>0.9994), and the lower limit of quantification (LLOQ) was 2.5 ng/mL for both. Moreover, the intra- and interday precision relative standard deviation (RSD) of KET and NK were less than 4.31% and 6.53%, respectively. The accuracies (relative error) of KET and NK were below -1.41% and -6.07%, respectively. The extraction recoveries of KET and NK were more than 81.23±3.45% and 80.42±4.57%, respectively. This sensitive, rapid, and selective UPLC-MS/MS method was successfully applied to study the pharmacokinetic effects of l-THP on KET after gastric gavage. The results demonstrated that l-THP could increase the bioavailability of KET and promote the metabolism of KET. The results showed that l-THP has pharmacokinetics effects on KET in rat plasma.


2006 ◽  
Vol 89 (3) ◽  
pp. 786-796 ◽  
Author(s):  
Dieter Zimmer ◽  
Christiane Philipowski ◽  
Birgit Posner ◽  
Agnes Gnielka ◽  
Edgar Dirr ◽  
...  

Abstract This paper describes a selective and sensitive method that uses liquid chromatography/tandem mass spectrometry with positive electrospray ionization (ESI+) for the determination of deltamethrin in a variety of crops. Samples were extracted by conventional high-speed blending. Some samples required no further cleanup; others were cleaned up by gel permeation chromatography, strong cation-exchange cartridges, or partitioning with n-hexane. In the determinative step, the buffered neutral mobile phase, consisting of 10 mM ammonium acetate (pH 6.8) and methanol, and ESI+ provided strong ammonium adduct formation to [M+NH4]+ at m/z 523, and the multiple-reaction monitoring (MRM) transition at m/z 523/281 was used for the quantitation of deltamethrin. A second MRM transition at m/z 525/283 was used for confirmation. The limit of quantitation (LOQ) values were 0.01 mg/kg for edible materials and 0.05 mg/kg for nonedible materials. Mean overall recoveries at the LOQ and the 10-fold LOQ ranged from 73 to 96%, and the relative standard deviations were &lt;10% for all samples materials analyzed.


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1330 ◽  
Author(s):  
Yongho Shin ◽  
Jiho Lee ◽  
Eunyoung Park ◽  
Junghak Lee ◽  
Hye Lee ◽  
...  

Multiresidual pesticide determination in a biological sample is essential for an immediate decision and response related to various pesticide intoxications. A rapid and simultaneous analytical method for 260 pesticides in human urine was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). High speed positive/negative switching electrospray ionization (ESI) mode was used, and scheduled multiple reaction monitoring (MRM) was optimized. Three versions of scaled-down QuEChERS procedures were evaluated, and the procedure using non-buffer reagents (magnesium sulfate and sodium chloride) and excluding cleanup steps was selected for optimum pesticide extraction. The limit of quantitation (LOQ) in this methodology was 10 ng/mL for each target pesticide, and correlation coefficient (r2) values of calibration curves were ≥0.988 (linearity range; 10–250 ng/mL). In accuracy and precision tests, the relative error ranges were −18.4% to 19.5%, with relative standard deviation (RSD) 2.1%–19.9% at an LOQ level (10 ng/mL), and −14.7% to 14.9% (RSD; 0.6%–14.9%) at higher concentrations (50, 150, and 250 ng/mL). Recovery range was 54.2%–113.9% (RSD; 0.3%–20.0%), and the soft matrix effect (range; −20% to 20%) was observed in 75.4% of target pesticides. The established bioanalytical methods are sufficient for application to biomonitoring in agricultural exposures and applicable in the forensic and clinic.


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