Urine samples laboratory analysis

Stephanie Marquardt, a technician in the bioanalytical laboratory at the MDS Pharma Services laboratory in Lincoln, Nebraska, prepares open columns for the preparation of urine samples for analysis for mutagens. 

In the clinical laboratory, the gross sample is usually satisfactory for use as the sample because it is not large and it is homogeneous (e.g., blood and urine samples). The analysis sample will usually be firom a few milliliters to a firaction of a drop (a few microliters) in quantity. 

Calculation of ID using biological monitoring techniques requires the knowledge of the pharmacokinetics of the parent pesticide in laboratory animals. This will allow the use of the parent or its urine metabolite(s) to calculate the total amount of the parent that had been absorbed through the skin of the test subject. The amount of the residue in the urine should be corrected for any molecular weight differences between the parent and its urine metabolite(s) and also corrected for daily urine excretion volumes based on creatinine analysis of the urine samples. 

Many antipsychotics show great interindividual variation in plasma levels and so analysis of therapeutic levels can be important clinically as well as in the research laboratory. In addition, nonresponse to the drugs may actually be due to excessive levels of neuroleptics, a paradoxical situation that requires analysis to identify (Rockland, 1986). Several methods using FID were cited in the previous edition of the Handbook of Neurochemistry but ECD and NPD have both shown utility for the typically low therapeutic levels (Cooper, 1988). GC-FID has been used to analyze levels of clozapine in blood, gastric, and urine samples in fatal cases of overdose with this drug (Ferslew et al., 1998), and olanzapine has been measured in blood and urine samples by GC-NPD in overdoses (Stephens et al., 1998). 4-(4-Chlorophenyl)-4-hydroxypiperidine, a metabolite of haloperidol, was analyzed in urine, plasma, brain, and liver from haloperidol-treated rats by GC-ECD, after derivatization with PFBC under aqueous conditions (Fang et al., 1996). 

The tests are designed to predict which of seven categories of drug the suspect may have used (1) CNS depressants, (2) CNS stimulants, (3) cannabinoids, (4) phencyclidine, (5) opioids, (6) hallucinogens, and (7) inhalants. The combination of results from the laboratory analysis of the blood or urine sample and from the 12-step evaluation test will help decide whetherthe defendant was impaired at the time of the stop. 

Biological Samples. There were three types of biological samples obtained from workers at the plant urine, whole blood, and feces. All urine and blood samples were internally "spiked" at the factory with 1 yg/mL of a nitrosopiperidine (NPiP) standard. NPiP was used for spiking because it has a similar stability and recovery characteristic to nitrosomorpholine, and to provide a means of gauging the accuracy of the analytical methods. Due to the inability to perform homogeneous mixing on-site, the feces samples were not spiked until they were thawed upon return to the laboratory. Ethyl acetate extracts of urine samples were examined for the presence of N-nitrosodiethanolamine (NDEIA), a metabolite of NMOR, by HPLC-TEA. All samples were immediately frozen at the plant (-80°C) and kept at this temperature until analysis. 

Acylcarnitine analysis was first performed in urine specimens in the evaluation of patients with organic acidemias. However, because it was found that acylcarnitine analysis of plasma is more informative for the diagnosis of FAO disorders than analysis of urine specimens, plasma has become the preferred specimen [17]. It is only recently that it was shown that urine acylcarnitine analysis still has a role in the diagnostic evaluation of patients with organic acidurias but uninformative or borderline abnormal results of plasma acylcarnitine and urine organic acid analysis [18-21]. In our laboratory, sample preparation and analysis is identical to that of plasma once a urine aliquot has been prepared that is based on the creatinine concentration. 

Sample handling. All urine samples were stored frozen by each subject until collected and transported to a laboratory. Upon receipt of the frozen urine samples, they were weighed, thawed (in the case of the North Dakota workers they were subsampled at the Plant Metabolism Laboratory, Fargo, North Dakota, and refrozen prior to shipping to Beltsville, Maryland), assigned a code, and returned to a refrigerator (5°C) pending analysis. 

Analysis. The Washington State urine samples were analyzed at the ARS Yakima Agricultural Research Laboratory and the North Dakota samples at the ARS Pesticide Degradation Laboratory at Beltsville, Maryland. The method used by both laboratories was a similar procedure based on a method developed at Yakima (Maitlen and Sell, unpub.). Several randomly selected urine samples were... 

Table III. Comparative 2,4-D (ppm) Analysis of Urine Samples between the Yakima and Beltsville Laboratories. ...

The authors thank the 43 volunteer 2,4-D applicators who participated in this study North Dakota State University Extension personnel and the Washington State Chapter of National Agricultural Aviation Association who contacted the participants W. C. Aller, Yakima Laboratory for collection of urine samples from Eastern Washington and assistance in the analysis of these samples and D. S. Frear, Plant Metabolism Laboratory, USDA, SEA-AR, Fargo, North Dakota. 

Many of the private laboratories offer screening for heavy metals (including lead, mercury, cadmium, arsenic, aluminum, and nickel) and other chemicals, such as PCBs, chlorinated solvents, trichloroethylene, and pesticides. One such laboratory advertised testing for nearly 70 chemicals. Occupational screening was also offered at some of the laboratories. For many laboratories, people may order test and screening kits over the Internet, by fax, or by telephone. A person can send in a blood, urine, or hair sample for analysis. In some cases, a physician s signature is required to have the sample tested. 

The discussion will proceed by reviewing the major issues in selection of biomarkers for study, developing the sampling strategy to answer the study questions, and assessing the communication and ethical considerations that must be addressed before the study is conducted. Next, the chapter will review the major considerations regarding the execution of the study, selection of the appropriate matrix (such as, blood or urine), collection of samples, transportation of samples to the laboratory, analysis of the samples, and banking of the specimens, when relevant, for future additional analyses. Finally, we review key considerations in the statistical analysis of the laboratory results. 

During an acute attack, a fresh urine sample which has been protected from light should be sent to a specialist laboratory to be tested for aminolaevulinic acid and porphobilinogen concentrations. If urinalysis confirms raised urinary excretion of aminolaevulinic acid and porphobilinogen, an analysis of faecal porphyrins can be used to identify the specific porphyria. In acute intermittent porphyria faecal porphyrin levels are generally normal. 

A variety of items within an NDA serve as assurance that the information in the application is correct and reliable. Each nonclinical toxicology or safety study should have a QA statement indicating compliance with the GLP regulations. If a laboratory conducting one or more of the studies has not provided a QA statement in the report, the NDA should explain the omission. In current general practice by pharmaceutical firms and contract laboratories, GLP regulations are also applied to the analysis of the drug in plasma, serum, or urine samples from clinical studies. 

Urine sampling may be conducted on a spot basis (e.g. end-of-shift or morning void), or as a complete 24 h sample. This latter sample, while more easily interpretable, is often difficult to obtain from workers. Sample collection is relatively simple and noninvasive, although issues of privacy and confidentiality need to be addressed. Laboratory analysis is generally complex, and therefore expensive. New techniques, such as enzyme-linked immunosorbent assays (ELISAs) show promise as simple and cost-effective analytical methods. Such methods, while useful to indicate exposure, are not suitable for quantifying exposure. 

The function of clinical chemistry in toxicology (as well as in human and veterinary medicine) is to provide, via laboratory analysis, evaluations of the qualitative and quantitative characteristics of specific endogenous chemical components present in samples of blood, urine, feces, spinal fluid, and tissues. The purpose is to help identify abnormal or pathological changes in organ system functions. The most common specimens used in clinical chemistry are blood and urine, and many different tests exist to test for almost any type of chemical component in blood or urine for example, blood glucose, electrolytes, enzymes, hormones, lipids (fats), other metabolic substances, and proteins. The tests used were all initially applied to human clinical medicine, and may not possess the same utility when performed as part of nonclinical toxicity studies in a wide variety of other species. 

Laboratory analysis of drinking water may be required to assess possible fluoride excess in natural well waters and may also be necessary during incidents of failure of the equipment used to treat drinking water. The determination of fluoride in urine can be used to assess exposure to different sources of fluoride. For drinking water and urine, direct determination using a fluoride-specific electrode is employed. For food, feces, and tissue, prior separation of fluoride from the sample matrix is required using a Conway diffusion procedure. The combination of the fluoride-electrode with flow injection has allowed a rapid and sensitive method to be used for serum and urine fluoride analysis/ ... 

Many different samples are available for clinical laboratory analysis before and during pregnancy. These include paternal serum and blood maternal serum, blood, and urine amniotic fluid obtained by amniocentesis or from pools of fluid in the vagina after rupture of the fetal membranes chorionic villi fetal blood obtained by percutaneous umbilical blood sampling and fetal tissue obtained by biopsy. ... 

The first fully automated instrument for chemical analysis (the Technicon Auto Analyzer ) appeared on the market in 1957. This instrument was designed to fulfill the needs of clinical laboratories, where blood and urine samples are routinely analyzed for a dozen or more chemical species. The number of such analyses demanded by modern medicine is enormous, so it is necessary to keep their cost at a reasonable level. These two considerations motivated the development of analytical. systems that perform several analyses simultaneously with a minimum input of human labor. The use of automatic instruments has spread from clinical laboratories to laboratories for the control of industrial processes and the routine determination of a wide spectrum of species in air, water, soils, and pharmaceutical and... 

Published Reports (1995-2006) of Laboratory Analysis of Human Urine Samples for Hydrolysis Metabolites Following a Suspected Exposure to Sulfur Mustard... 

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