scholarly journals Dried Urine Microsampling Coupled to Liquid Chromatography—Tandem Mass Spectrometry (LC–MS/MS) for the Analysis of Unconjugated Anabolic Androgenic Steroids

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.

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.


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.


Author(s):  
C A Chadwick ◽  
L J Owen ◽  
B G Keevil

Background: Dehydroepiandrosterone sulphate (DHEAS) is a steroid that is increasingly being recognized as a potential drug of abuse in many countries. This is due to its reputation as a hormone that may be able to retard the ageing process. The measurement of DHEAS is useful in the diagnosis of medical conditions such as congenital adrenal hyperplasia and polycystic ovary syndrome. Thus, a liquid chromatography-tandem mass spectrometry method has been developed to determine DHEAS concentrations in human serum. Method: The chromatography was performed using a WatersTM 2795 Alliance HT LC system coupled to a Mercury Fusion-RP column fitted with a SecurityGuardTM column. Results: DHEAS and the internal standard, deuterated DHEAS, both had a retention time of 1.5 min. The transition determined by the Micromass QuattroTM tandem mass spectrometer for DHEAS was m/z 367.3>96.7 and for the internal standard m/z 369.3>96.6. The method was linear up to 20 µmol/L; the lower limit of detection and the lower limit of quantitation were both 1 µmol/L. The intra- and interassay imprecision were <11% over a concentration range of 1-18 µmol/L for the in-house quality control and <12% for the intra- and interassay imprecision for the Bio-Rad Lyphocheck QC. Conclusion: The measurement of DHEAS by liquid chromatography-tandem mass spectrometry is robust and has a simple sample preparation procedure with a rapid cycle time of only 4 min.


Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1254 ◽  
Author(s):  
Won-Gu Choi ◽  
Dong Kyun Kim ◽  
Yongho Shin ◽  
Ria Park ◽  
Yong-Yeon Cho ◽  
...  

Doxorubicin, an anthracycline antitumor antibiotic, acts as a cancer treatment by interfering with the function of DNA. Herein, liquid chromatography-tandem mass spectrometry was for the first time developed and validated for the simultaneous determination of doxorubicin and its major metabolites doxorubicinol, doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone in mouse plasma. The liquid–liquid extraction of a 10 μL mouse plasma sample with chloroform:methanol (4:1, v/v) and use of the selected reaction monitoring mode led to less matrix effect and better sensitivity. The lower limits of quantification levels were 0.5 ng/mL for doxorubicin, 0.1 ng/mL for doxorubicinol, and 0.01 ng/mL for doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone. The standard curves were linear over the range of 0.5–200 ng/mL for doxorubicin; 0.1–200 ng/mL for doxorubicinol; and 0.01–50 ng/mL for doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone in mouse plasma. The intra and inter-day relative standard deviation and relative errors for doxorubicin and its four metabolites at four quality control concentrations were 0.9–13.6% and –13.0% to 14.9%, respectively. This method was successfully applied to the pharmacokinetic study of doxorubicin and its metabolites after intravenous administration of doxorubicin at a dose of 1.3 mg/kg to female BALB/c nude mice.


2017 ◽  
Vol 80 (12) ◽  
pp. 2112-2118 ◽  
Author(s):  
Dan Hu ◽  
Xu Xu ◽  
Tian Cai ◽  
Wei-Ying Wang ◽  
Chun-Jie Wu ◽  
...  

ABSTRACTA rapid and sensitive analytical method based on high-performance liquid chromatography–tandem mass spectrometry was developed and validated for the determination of isopyrazam (IZM) and azoxystrobin (AZT) in cucumbers. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used as the pretreatment procedure. The samples were extracted with acetonitrile and cleaned up with octadecylsilyl silica (C18) and graphite carbon black. The proposed method resulted in satisfactory recovery of IZM and AZT (91.48 to 114.62%), and relative standard deviations were less than 13.1% at fortification concentrations of 1, 20, and 500 μg kg−1 (n = 3). The limits of quantification for IZM and AZT were 0.498 and 0.499 μg kg−1, respectively, which are far below the maximum residue level (0.5 mg kg−1) established for this type of sample. Matrix effects were also evaluated. This study established a sensitive and fast method for the detection of IZM and AZT in cucumber samples.


Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4399
Author(s):  
Dasom Shin ◽  
Hui-Seung Kang ◽  
Hyungsoo Kim ◽  
Guiim Moon

In this work, liquid chromatography–tandem mass spectrometry (LC-MS/MS) method was developed and validated for screening and confirmation of 64 illicit compounds in dietary supplements. The target compounds were illegally used pharmaceutical drugs, prohibited compounds, and not authorized ingredients for different therapeutics (sexual enhancement, weight loss, muscular strengthening, and relaxing products). The validation procedure was performed to evaluate selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision according to the Association of Official Analytical Chemists guidelines. The linearity was >0.98 in the range of 0.5–200 µg L−1. The LOQs were in the range 1–10 µg kg−1 for all target compounds. The accuracy (expressed as recovery) was 78.5–114%. The precision (expressed as the relative standard deviation) was below 9.15%. The developed method was applied for the determination of illicit compounds in dietary supplements collected from websites. As a result, the total detection rate was 13.5% (27 samples detected in 200 samples). The concentrations of detected samples ranged from 0.51 to 226 mg g−1. The proposed methodology is suitable for monitoring the adulteration of illicit compounds in dietary supplements.


2008 ◽  
Vol 71 (5) ◽  
pp. 1038-1042 ◽  
Author(s):  
SHIGEKUNI NOBA ◽  
MASAYUKI OMOTE ◽  
YASUSHI KITAGAWA ◽  
NAOKI MOCHIZUKI

A simple and accurate method has been developed for determining ochratoxin A (OTA), using an immunoaffinity column for cleanup and liquid chromatography–tandem mass spectrometry for identification and quantification. Wine samples were diluted with a solution containing polyethylene glycol 8000 and sodium hydrogen carbonate, filtered through a glass microfiber filter, and cleaned up on an immunoaffinity column. OTA was then eluted with methanol–acetic acid (98:2) and analyzed by liquid chromatography–tandem mass spectrometry. The average recoveries of OTA from red and white wines were 95 and 96.7% (spiked OTA level was 0.05 ng/ml) and repeatabilities (relative standard deviation) were 3.8 and 2.4%, respectively. The detection limit was 0.0003 ng/ml based on the signal-to-noise ratio in wine of 3:1. Analysis of 74 samples of domestic and imported wines showed OTA levels ranging from &lt;0.0003 to 0.82 ng/ml, with an incidence of contamination of 92.1% for red wines, and &lt;0.0003 to 0.51 ng/ml, with an incidence of contamination of 77.8% for white wines. These detection rates were higher than those rates of past reports of OTA contamination in wine, due to the high sensitivity of this method. However, all samples analyzed in this study complied with European Union regulations. It is concluded that this method is a useful tool for the quality assurance of wine.


2014 ◽  
Vol 852 ◽  
pp. 266-269
Author(s):  
Xiao Fang Wang ◽  
Chun Liang Yang ◽  
Mao Fang Huang ◽  
Ming Yue Wang ◽  
Yu Bing Zha ◽  
...  

The conditions for detecting residues of diflubenzuron in vegetables by ultra high performance liquid chromatography tandem mass spectrometry were studied. The target was extracted with acetonitrile for 2 min with a homogenizer. The extaction was purifide by a conditioned Florisil SPE cartridge, and then was detected by ultra high-performance liquid chromatography with tandem mass spectrometry. The average recovery was in the range from 87.8 %- 99.2 % at spike levels of 0.1, 1.0 and 10 mg/kg in vegetables, and relative standard deviations was in the range of 4.2 %-8.9 %. The proposed method is fast, simple, sensitive and accurate.


Sign in / Sign up

Export Citation Format

Share Document