Reference materials for analytical toxicology including doping control: freeze-dried urine samples

The Analyst ◽  
2004 ◽  
Vol 129 (5) ◽  
pp. 449-455 ◽  
Author(s):  
C. Jiménez ◽  
R. Ventura ◽  
J. Williams ◽  
J. Segura ◽  
R. de la Torre
Keyword(s):  
Reference Materials ◽  
Doping Control ◽  
Urine Samples ◽  
Analytical Toxicology ◽  
Freeze Dried

Problems of ensuring metrological traceability of measurement results of indicators of quality for food products and food raw materials

2020 ◽  
pp. 64-70
Author(s):  
Mariya Y. Medvedevskikh ◽  
Anna S. Sergeeva
Keyword(s):  
Reference Materials ◽  
Mass Fraction ◽  
Nutritional Value ◽  
Animal Feed ◽  
Raw Materials ◽  
Meat Products ◽  
Metrological Traceability ◽  
Food Products ◽  
Freeze Dried ◽  
Measurement Results

The article raises the problem of ensuring metrological traceability of the measurement results of indicators of quality and nutritional value for food products and food raw materials: water (moisture), nitrogen (protein, crude protein), fat, ash and carbohydrates. The problem under consideration can be solved by applying reference materials of food composition, traceable to state primary measurement standards GET 173-2017 and GET 176-2019 and primary reference measurement procedures (PRMP), for attestation of measurement procedures and accuracy checking of measurement results. The article discusses the results of the PRMP development of mass fraction of fat, ash and carbohydrates in food products and food raw materials, as well as mass fraction of crude fat (oil content) in oil crops seeds and products based on them. The paper also presents metrological characteristics of reference materials of composition of dry dairy products, grain-milk dry porridges for nutrition of babies, grain dry porridges for nutrition of babies, egg powder, freeze-dried meat products, animal feed. The results of the work allow for building a chain of metrological traceability from GET 173-2017, GET 176-2019 and PRMP to routine measurement procedures, thereby ensuring the uniformity of measurements of nutritional value of food products.

scholarly journals A high-throughput and sensitive methodology for the quantification of urinary 8-hydroxy-2′-deoxyguanosine: measurement with gas chromatography-mass spectrometry after single solid-phase extraction

2004 ◽  
Vol 380 (2) ◽  
pp. 541-548 ◽  
Author(s):  
Hai-Shu LIN ◽  
Andrew M. JENNER ◽  
Choon Nam ONG ◽  
Shan Hong HUANG ◽  
Matthew WHITEMAN ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Solid Phase Extraction ◽  
Healthy Subjects ◽  
Solid Phase ◽  
Large Population ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Extraction ◽  
Freeze Dried ◽  
Wide Range

8-Hydroxy-2´-deoxyguanosine (8OHdG) is a widely used biomarker for the measurement of endogenous oxidative DNA damage. A sensitive method for the quantification of 8OHdG in urine by single solid-phase extraction and GC-MS (gas chromatography with MS detection) using selective ion monitoring is described in the present study. After solid-phase extraction, samples are freeze-dried, derivatized by trimethylsilylation and analysed by GC-MS. The urinary 8OHdG was quantified using heavy isotope dilution with [18O]8OHdG. The recovery of 8OHdG after the solid-phase extraction ranged from 70 to 80% for a wide range of urinary 8OHdG levels. Using 1 ml of urine, the limit of quantification was >2.5 nM (2.5 pmol/ml) and the calibration curve was linear in the range 2.5–200 nM. This method was applied to measure 8OHdG in urine samples from 12 healthy subjects. The intra- and inter-day variations were <9%. Urinary 8OHdG levels in spot urine samples from four healthy subjects were also measured for 1 week and, again, the variation was small. The presence of H2O2 in urine did not cause artifactual formation of 8OHdG. Since this assay is simple, rapid, sensitive and reproducible, it seems suitable to be used as a routine methodology for the measurement of urinary excretion of 8OHdG in large population studies.

scholarly journals Polyphenol Consumption on Human Bile Acids Metabolism: Preliminary Data of Bile Acid Profiles in Human Biological Samples (P06-131-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Anqi Zhao ◽  
Xuhuiqun Zhang ◽  
Amandeep Sandhu ◽  
Indika Edirisinghe ◽  
Barbara Shukitt-Hale ◽  
...  
Keyword(s):  
Bile Acid ◽  
Qualitative Analysis ◽  
Bile Acids ◽  
Biological Samples ◽  
Urine Samples ◽  
Fragmentation Pattern ◽  
Plasma Samples ◽  
Potential Health ◽  
Human Bile ◽  
Freeze Dried

Abstract Objectives Bile acids (BAs) play a critical role in regulating human health through the activation of BAs receptor farnesoid X receptor (FXR) and membrane G protein coupled bile acid receptor-1 (TGR5). We aimed to develop methods to characterize BAs and their metabolites in human biological samples and characterize changes in BAs profile after chronic polyphenol consumption to help guide investigations on the potential health effects of polyphenols via BAs metabolism. Methods Plasma, fecal and urine samples from two human studies that included berry intake were used for developing qualitative analysis of BAs using ultra high-performance liquid chromatography (UHPLC) coupled with electrospray ionization quadrupole time of flight (QTOF). The compounds were identified based on the exact mass, fragmentation pattern, available reference standards and database search. To investigate the effect of chronic polyphenol consumption on BAs composition, pooled plasma samples (fasting and postprandial 2 h, n = 6) from a chronic (45 and 90 days) strawberry supplementation study (24 g freeze dried/day) with an older population were analyzed. Results Among 106 BAs and their metabolites which were tentatively identified in the samples used for method development, 70, 55, and 47 BAs species were characterized in plasma, feces and urine samples, respectively. The qualitative analysis of BAs in plasma samples from subjects following the strawberry consumption protocol detected 8 primary and 31 secondary BAs. After 90-days strawberry supplementation, two secondary BAs–glycolithocholic acid and 9(11), (5β)-cholenic acid-3α, 12α-diol were decreased to undetectable levels in the pooled fasting sample and the FRX/TGR5 agonists, including chenodeoxycholic acid, deoxycholic acid, cholic acid, glycodeoxycholic acid and taurocholic acid, showed increasing peak areas at 2 h postprandial compared to fasting. Conclusions The changes in BAs profiles in fasting and postprandial plasma samples after chronic strawberry feeding suggest that strawberry polyphenols may alter BAs metabolism and the FXR/TGR5 signaling. Funding Sources This work was funded by the California Strawberry Commission, USDA Intramural Funds and various donor funds to the Center for Nutrition Research, IIT.

Spectrophotometric determination of urinary iodine by flow-injection analysis with on-line catalytic digestion

1996 ◽  
Vol 42 (12) ◽  
pp. 2021-2027 ◽  
Author(s):  
Z Yaping ◽  
Y Dongxing ◽  
C Jixiang ◽  
L Tianshiu ◽  
C Huiqin
Keyword(s):  
Flow Injection ◽  
Reference Sample ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Urine Samples ◽  
Injection Technique ◽  
Freeze Dried ◽  
On Line ◽  
Iodine In Urine

Abstract A flow-injection technique involving on-line catalytic digestion and spectrophotometric detection has been developed for the determination of iodine in urine. After urine samples are digested by KMnO4-K2Cr2O7-H2SO4 solution, the iodine in the urine catalyzes the reaction of As(III) with Ce(IV). The remaining Ce(IV) is then reacted with brucine and the product is detected with a spectrophotometer at 480 nm. With this technique, we obtained a detection limit for urinary iodine of 0.039 mumol/L, and the linear range was 0.039-7.88 mumol/L with a CV &lt; 3%. Analytical recovery ranged between 92% and 104% (mean 99%). The sampling frequency of the flow-injection technique was 70/h. We applied the method to measure the iodine concentration in a freeze-dried urine reference sample and in collected urine samples, and compared the results with those obtained by the accepted alkaline ashing technique. The proposed technique has the advantages of being simple, rapid, precise, accurate, and sensitive. It can be used to assess iodine-deficient populations as well as those receiving treatment.

scholarly journals Exceptional circumstances beyond International Swimming Federation Doping Control Rules: The Sun Yang case of Court of Arbitration for Sport

2021 ◽  
Vol 12 (1) ◽  
pp. 131-143
Author(s):  
Evgenia G. Vetrova ◽  
Raisa I. Khalatova ◽  
Anastasia A. Kashaeva
Keyword(s):  
Doping Control ◽  
Urine Samples ◽  
Control Procedure ◽  
The Sun ◽  
Destruction Process ◽  
Blood Samples ◽  
Urine Sampling ◽  
Control Rules ◽  
World Anti Doping Agency

The authors refer to the exceptional circumstances surrounding Sun Yang’s violation. The athlete intervened in the doping control procedure in several ways. First, he questioned the proper accreditation of the IDTM’s (The company “International Doping Tests and Management”) Samples Collection Personnel, one of which photographed him. This officer was suspended from urine sampling, but there was no longer a male specialist on the IDTM’s Samples Collection Personnel. Therefore, the collection of urine samples did not take place due to the athlete’s actions. A general distrust of IDTM’s Samples Collection Personnel due to inappropriate photographing was the catalyst for follow-up action. Secondly, the athlete required IDTM’s Samples Collection Personnel to confirm his credentials (accreditation) from the anti-doping organization, despite the submission of documents by IDTM’s Samples Collection Personnel following the International Standard for Testing and Investigations. Not having received the additional and, in the opinion of the athlete, necessary documents, he refused to participate in the doping control procedure as a whole, tearing up his previously given written consent. Finally, the athlete took part in the destruction of blood samples with a hammer, but his role in this process was controversial. A prerequisite for the destruction process of the samples was the assistance of the IDTM’s Samples Collection Personnel, who handed them over to the athlete in response to insistent demands. The listed circumstances, which are exceptional, however, could not affect the reduction of Sun Yang’s period of ineligibility, since the FINA (International Swimming Federation) Doping Control Rules, based on WADA (World Anti-Doping Agency) Code 2015, do not imply such a basis. The new WADA Code 2021 offers a more flexible concept of liability and takes into account exceptional circumstances that in subsequent disputes about tampering can be established based on the example of the dispute CAS 2019/A/6148.

scholarly journals Application of the lyophilization system for preparation of reference materials for composition of nutrition products

2021 ◽  
Vol 17 (1) ◽  
pp. 35-45
Author(s):  
M. Y. Medvedevskikh ◽  
N. L. Vostrikova ◽  
A. S. Sergeeva ◽  
V. V. Studenok
Keyword(s):  
Reference Materials ◽  
Fat Mass ◽  
Mass Fraction ◽  
Primary Standard ◽  
Poultry Meat ◽  
Chicken Breast ◽  
Homogeneous Material ◽  
Freeze Dried ◽  
Air Dryer ◽  
Certified Values

The article presents the application of the lyophilization system for preparation of reference materials (RM) for composition of nutritive products samples. The purpose of the research was the development of lyophilization procedure of RM for composition of poultry meat samples preparation with certified values of mass fraction of moisture, nitrogen (protein) and fat.The poultry meat of two types was used as the primary material for RM for poultry meat composition preparation -1) white meat (chicken breast); 2) red meat (chicken thigh). The procedure included pounding, boiling, freezing and lyophilisation (syn. freeze drying). The researches for homogeneity were implemented with hot air dryer standard system from the State primary standard GET 173-2017. Measurement of nitrogen (protein) mass fraction was performed on State secondary standard GVET176-1-2010. Measurements of fat mass fraction were performed with accordance to State Primary Reference Measurement Procedure.The total time of lyophilization process for samples № 1 and № 2 was 19 and 28 hours, respectively. The total mass loss for sample № 1 was about 63 %, for sample № 2 was about 65 %. The difference in material moisture mass fraction values of materials dried on different trays of freeze dryer was statistically significant, i. e., material was non-homogeneous. To obtain a homogeneous material, an additional homogenization procedure was performed: grinding in a laboratory mill, sieving through a sieve, thorough mixing and conditioning. The certified values of moisture, nitrogen, protein, fat mass fraction for the sample № 1 were accordingly 4,5 %, 14,74 %, 92,1 %, 7,9 %. The same values in the same sequence were 6,3 %, 12,21 %, 76,3 %, 23,8 %.The procedure of lyophilisation was developed for production of reference materials for composition of boiled and freeze-dried poultry meat. The usage of this lyophilisation system allowed to ensure a RM expiration date of six months at ambient temperature of (7±3) °C and relative humidity no more than 60 %. The Reference Materials for composition of boiled and freeze-dried poultry meat was added into Register of certified RMs under № GSO 11276-2019 by the results.

scholarly journals Pilot study on the effects of intravesical oxybutynin hydrochloride instillations on the validity of doping control urine samples

2019 ◽  
Vol 11 (11-12) ◽  
pp. 1755-1760 ◽  
Author(s):  
Katja Walpurgis ◽  
Anja B. Scheiff ◽  
Meike Welz ◽  
Jutta Müller‐Reul ◽  
Nick Webborn ◽  
...  
Keyword(s):  
Pilot Study ◽  
Doping Control ◽  
Urine Samples ◽  
Oxybutynin Hydrochloride

Epidemiological investigation of the UGT2B17 polymorphism in doping control urine samples and its correlation to T/E ratios

2011 ◽  
Vol 3 (10) ◽  
pp. 645-651 ◽  
Author(s):  
Patricia Anielski ◽  
Juliane Simmchen ◽  
Lars Wassill ◽  
Dirk Ganghofner ◽  
Detlef Thieme
Keyword(s):  
Doping Control ◽  
Urine Samples ◽  
Epidemiological Investigation ◽  
In Doping
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