A Rapid and Efficient Autoclave Pre-Treatment to Extract Iodine-129 from Urine Samples for AMS Analysis

10.26434/chemrxiv.13296359.v1 ◽

2020 ◽

Author(s):

Fahad Alotaibi ◽

Matthew N. Herod ◽

R. Jack Cornett

Keyword(s):

Human Urine ◽

Urine Samples ◽

New Method ◽

Isotopic Ratios ◽

Relative Importance ◽

Chemical Waste ◽

Human Diet ◽

Pre Treatment ◽

Yield Tracer ◽

Iodine Sufficiency

A new method was developed to extract 129I from urine samples and then measure it by AMS. The samples were pre-treated in an autoclave with hydrogen peroxide to remove unwanted compounds from the urine samples and were acidified with nitric acid, followed by precipitation of iodine as silver iodide (AgI) for measurement by AMS. This new procedure is substantially faster than previous methods for the extraction of iodine from urine and results in less chemical waste. The efficiency and reproducibility of this method were evaluated by using 125I as a yield tracer, eventually giving a recovery above 99%. To achieve this, several iterations of the method were required. The method was then successfully applied to measure 129I/127I isotopic ratios and 129I concentrations in 25 human urine samples. The AMS results for 129I in urine ranged 3.3 x 106 atoms/L to 884 x 106 atoms/L and the isotope ratio (129I/127I) in human urine ranged from 7.38 x 10-12 to 3.97 x 10-10 with a median of 1.29 x 10-10. This new method will be useful for investigations into the sources of iodine in the human diet and their relative importance for iodine sufficiency.

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Studies on Creation of a New Method for Evaluating Vitamin Nutrition Using Human Urine Samples

Nippon Eiyo Shokuryo Gakkaishi ◽

10.4327/jsnfs.66.3 ◽

2013 ◽

Vol 66 (1) ◽

pp. 3-8 ◽

Cited By ~ 2

Author(s):

Katsumi Shibata

Keyword(s):

Human Urine ◽

Urine Samples ◽

New Method ◽

Human Urine Samples

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Electrochemical Reduction Behavior Of Mephedrone Drug At A Dropping Mercury Electrode And Its Pharmaceutical Determination In Spiked Human Urine Samples

International Journal of Scientific Research ◽

10.15373/22778179/sep2012/5 ◽

2012 ◽

Vol 1 (4) ◽

pp. 14-17

Author(s):

V. Krishnaiah V. Krishnaiah ◽

◽

Y. V. Rami Reddy ◽

V. Hanuman Reddy ◽

M. Thirupalu Reddy ◽

...

Keyword(s):

Electrochemical Reduction ◽

Human Urine ◽

Mercury Electrode ◽

Urine Samples ◽

Reduction Behavior ◽

Human Urine Samples ◽

Dropping Mercury Electrode ◽

Spiked Human Urine

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The influence of taurine and L-carnitine on 6 β-hydroxycortisol/cortisol ratio in human urine of healthy volunteers

Drug Metabolism and Personalized Therapy ◽

10.1515/dmpt-2019-0013 ◽

2019 ◽

Vol 34 (3) ◽

Cited By ~ 1

Author(s):

Anna A. Makhova ◽

Eugenia V. Shikh ◽

Tatiana V. Bulko ◽

Zhanna M. Sizova ◽

Victoria V. Shumyantseva

Keyword(s):

Catalytic Activity ◽

Healthy Volunteers ◽

Human Urine ◽

Biologically Active Compounds ◽

Biologically Active ◽

Metabolic Ratio ◽

Urine Samples ◽

Cyp3a4 Activity ◽

Active Compounds ◽

Cortisol Ratio

Abstract Background Cytochrome P450s (CYPs, EC 1.14.14.1) are the main enzymes of drug metabolism. The functional significance of CYPs also includes the metabolism of foreign chemicals and endogenic biologically active compounds. The CYP3A4 isoform contributes to the metabolism of about half of all marketed medicinal preparations. The aim of this study was to investigate the effects of two biologically active compounds: 2-aminoethane-sulfonic acid (taurine) and 3-hydroxy-4-trimethylaminobutyrate (L-carnitine) on urinary 6β-hydroxycortisol/cortisol (6β-OHC/cortisol) metabolic ratio as a biomarker of the CYP3A4 activity of healthy volunteers. Taurine is used for the treatment of chronic heart failure and liver disease. Cardiologists, nephrologists, neurologists, gerontologists in addition to the main etiopathogenetic therapies, use L-carnitine. The quantification of the 6β-OHC/cortisol metabolic ratio as a biomarker of CYP3A4 activity in human urine was used for the assessment of CYP3A4 catalytic activity as a non-invasive test. Methods The study included 18 healthy male volunteers (aged from 18 to 35 years old). The volunteers took taurine in a dose of 500 mg twice a day or L-carnitine in a dose of 2.5 mL 3 times a day for 14 consecutive days. The test drug was given 20 min before meals. The collection of urine samples was performed before and after 3, 7, 10, and 14 days after taurine intake. The metabolic ratio of 6β-OHC/cortisol in morning spot urine samples was studied by the liquid chromatography/mass spectroscopy (LC/MS) method. Results The ratio of 6-6β-OHC/cortisol was used as a biomarker to study the taurine and L-carnitine influence on CYP3A4 metabolism of cortisol. The ratio of urinary 6β-OCH/cortisol in the morning urine samples of volunteers before the beginning of taurine therapy (baseline ratio) was 2.71 ± 0.2. Seven days after the administration of taurine in a dose of 500 mg twice a day, the 6β-OCH/cortisol ratio was 3.3 ± 0.2, which indicated the increased catalytic activity of CYP3A4 towards cortisol. As for the L-carnitine supplementation, analysis of the 6β-OCH/cortisol ratio in the urine for 14 days did not show any significant changes in this baseline ratio, indicating the lack of L-carnitine influence on the catalytic activity of CYP3A4 to cortisol. Conclusions The results obtained demonstrated the influence of taurine on 6β-OCH/cortisol metabolic ratio as a biomarker of CYP3A4 catalytic activity to cortisol. L-carnitine did not affect the activity of CYP3A4. The lack of a clinically meaningful effect of L-carnitine was established.

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Highly selective and sensitive differential pulse voltammetric method based on poly(Alizarin)/GCE for determination of cefadroxil in tablet and human urine samples

Arabian Journal of Chemistry ◽

10.1016/j.arabjc.2021.103296 ◽

2021 ◽

pp. 103296

Author(s):

Adane Kassa ◽

Meareg Amare

Keyword(s):

Human Urine ◽

Differential Pulse ◽

Urine Samples ◽

Voltammetric Method ◽

Human Urine Samples

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Evaluation of TaqMan based real-time PCR assay targeting LipL32 gene for leptospirosis in serologically positive human urine samples from north India

Indian Journal of Medical Microbiology ◽

10.1016/j.ijmmb.2020.10.017 ◽

2020 ◽

Author(s):

Surabhi Shukla ◽

Vineeta Mittal ◽

Peetam Singh ◽

Aditi Singh

Keyword(s):

Real Time ◽

Human Urine ◽

Real Time Pcr ◽

Urine Samples ◽

North India ◽

Pcr Assay ◽

Human Urine Samples

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Dried urine spots as sampling technique for multi-mycotoxin analysis in human urine

Mycotoxin Research ◽

10.1007/s12550-021-00423-1 ◽

2021 ◽

Author(s):

Jessica Schmidt ◽

Viktoria Lindemann ◽

Monica Olsen ◽

Benedikt Cramer ◽

Hans-Ulrich Humpf

Keyword(s):

Ochratoxin A ◽

Human Urine ◽

Sampling Strategy ◽

Sampling Technique ◽

Human Biomonitoring ◽

Urine Samples ◽

Isotope Dilution Analysis ◽

Tenuazonic Acid ◽

Stable Isotope Dilution Analysis ◽

Mycotoxin Analysis

AbstractA simple and effective approach for HPLC-MS/MS based multi-mycotoxin analysis in human urine samples was developed by application of dried urine spots (DUS) as alternative on-site sampling strategy. The newly developed method enables the detection and quantitation of 14 relevant mycotoxins and mycotoxin metabolites, including citrinin (CIT), dihydrocitrinone (DH-CIT), deoxynivalenol (DON), fumonisin B1 (FB1), T-2 Toxin (T-2), HT-2 Toxin (HT-2), ochratoxin A (OTA), 2′R-ochratoxin A (2′R-OTA), ochratoxin α (OTα), tenuazonic acid and allo-tenuazonic acid (TeA + allo-TeA), zearalenone (ZEN), zearalanone (ZAN), α-zearalenol (α-ZEL), and β-zearalenol (β-ZEL). Besides the spotting procedure, sample preparation includes enzymatic cleavage of glucuronic acid conjugates and stable isotope dilution analysis. Method validation revealed low limits of detection in the range of pg/mL urine and excellent apparent recovery rates for most analytes. Stability investigation of DUS displayed no or only slight decrease of the analyte concentration over a period of 28 days at room temperature. The new method was applied to the analysis of a set of urine samples (n = 91) from a Swedish cohort. The four analytes, DH-CIT, DON, OTA, and TeA + allo-TeA, could be detected and quantified in amounts ranging from 0.06 to 0.97 ng/mL, 3.03 to 136 ng/mL, 0.013 to 0.434 ng/mL and from 0.36 to 47 ng/mL in 38.5%, 70.3%, 68.1%, and 94.5% of the samples, respectively. Additional analysis of these urine samples with an established dilute and shoot (DaS) approach displayed a high consistency of the results obtained with both methods. However, due to higher sensitivity, a larger number of positive samples were observed using the DUS method consequently providing a suitable approach for human biomonitoring of mycotoxin exposure.

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