Urine reference material

There are no special problems with the reconstitution or handling of these kinds of materials for electrolytes. The concentration of electrolytes is high, and no contamination problems are to be expected. Many commercial suppliers deliver reference materials for electrolytes in serum and urine. 

Solvents or their metabolites are commonly determined by GC (Tokunaga et al. 1974) or GC-MS. In spite of the high importance of exposure to solvents, and the great number of determinations performed worldwide, reference materials for solvents in serum or urine are virtually non-existent. There are a number of reference materials used in occupational hygiene, for example the ethanol in water standard from NIST (SRM 1828a) is commonly used in the clinical laboratory. 

Even though PAHs are commonly determined by GC or HPLC, there are no matrix reference materials for PAHs in urine or serum. A number of reference materials certified for PAHs in animal tissue are available, but they are intended for environmental applications, see Section 3.4. 

Many pesticides are neurotoxicants poisoning the nervous system. A number of pesticides are acetyl cholinesterase inhibitors (Serat and Mengle 1973). Generally, pesticides determination has been performed by GC since the 1960 s (Morrison and Durham 1971 Fournier et al. 1978). There are no reference materials for pesticides in urine or serum, although as with PAHs there are a number biological matrices certified for the content of various pesticides available for environmental food and agriculture analysis and which may have some application in clinical chemistry. 

Zheng, J., Kosmus, W., Pichler-Semmelrock, F., and Kock, M., Arsenic speci-ation in human urine reference materials using high-performance liquid chromatography with inductively coupled plasma mass spectrometric detection, /. Trace Elements Med. Biol., 13, 150, 1999. 

Tai SS, Welch MJ. 2000. Determination of ll-nor-delta9-tetrahydrocannabinol-9-carboxylic acid in a urine-based standard reference material by isotope-dilution liquid chromatography-mass spectrometry with electrospray ionization. J Anal Toxicol 24 385. 

Reference material (in preparation) Urine Muscle — Urine... 

The Czech Reference Material CZ 6007a for total protein and creatinine in human urine was prepared [2], and served as a preliminary batch for the preparation of a certified reference material (CRM) for the stress indicators adrenaline (A), noradrenaline (NA) and dopamine(DA)in human urine. Some major problems in the traceability of these different analytes are presented. 

A reference material (RM) for traceability of total protein in human urine does not exist. The control materials used in clinical laboratories for calibration purposes are not unified. Some laboratories use bovine serum albumin as a calibration material (URINE-CHIMIE BIOTROL) [5], whereas others use a mixture of human serum albumin (70%) and globulin (30%) (LYPHOCHECK Quantitative Urine Control, BIO-RAD) [6]. The use of various protein calibration standards yields various results of... 

The problem of developing accurate data for chromium in biological samples is further complicated by the lack of Standard Reference Materials (SRM). Only recently have chromium certified materials, such as brewer s yeast (SRM-1569), bovine liver (SRM-1577), human serum (SRM-909), urine (SRM-2670), orchard leaves (SRM-1571), spinach leaves (SRM-1570), pine needles (SRM-1575), oyster tissue (SRM-1566), and tomato leaves (SRM-1573) been issued by the National Institute of Standards and Technology (formerly the National Bureau of Standards). Because of the lack of SRMs, the less recent data should be interpreted with caution (EPA 1984a), unless the data are verified by interlaboratory studies. 

MS. After careful homogenization, the dried urine samples were analyzed directly by LA-ICP-MS without any time consuming digestion procedure. Matrix matched synthetic laboratory standards doped with Th (IRMM 60), uranium with natural isotope composition ( U/ U = 0.00725) and uranium isotope standard reference material (NIST U-930) at the low pgml level were prepared in order to smdy the figures of merit of the analytical methods developed. The recovery rate for thorium and uranium concentration measured on a synthetic urine laboratory standard by LA-ICP-MS varied between 91 and 104%. The precision and accuracy of the analytical methods was found to be 7 % and < 1 %, respectively, for uranium concentration, by using urine laboratory standards (at uranium concentration O.lngml. ... 

Wrobel, K., Wrobel, K., Parker, B., Kannamkumarath, S.S., Caruso, J.A. Determination of As(III), As(V), monomethylarsonic acid, dimethylarsinic acid and arsenobetaine by HPLC-ICP-MS analysis of reference materials, fish tissues and urine. Talanta 58, 899-907 (2002)... 

Freeze-dried materials for urine samples are nearly as commonplace as serum samples. These materials possess long-term stability and are used for the determination of pentachlorophenol [25] and metals such as Pb [26] and Cd [27], among others. In most cases, the results for the freeze-dried reference material are indistinguishable from those for fresh urine. 

The extraction techniques in current use in most laboratories throughout the world are still based on the kaolin-acetone procedures of Albert (A2) and Loraine and Brown (L8) or the tannic acid method of Johnsen (Jl). There is little information in the literature regarding the reliability criteria of these methods. Loraine and Brown tested the accuracy of their kaolin-acetone method in a series of recovery experiments in which a reference material prepared from urine, HMG-20A, was added to urine and recovered the end point of the bioassay was the mouse uterus test for total gonadotropic activity. The mean percentage recovery was 76,... 

Human urine reference materials (NIST SRM 2670E and 2670N)... 

Sloth, J. J., Julshamn, K., Larsen, E. H. Selective arsenic speciation analysis of human urine reference materials using gradient elution ion-exchange HPLC-ICP-MS. J Anal At Spectrom 2004, 19, 973-978. 

Certified reference materials (CRMs) with certified values for Al available at the time of preparation of this review from the Institute for Reference Materials and Measurements, European Community Joint Research Centre were ground water, an aquatic plant, olive leaves, beech leaves, pine needles, lichen and titanium (http // www.irmm.jrc.be). Non-Al-certified materials available were coals, river sediment, seawater, zinc and zinc alloys and titanium alloy. CRMs with certified values for Al were available from the US National Institute of Standards and Technology (http // www.nist.gov/) for days, coal, coal fly-ash, glasses, limestone, lubricating oil, a met-allo-organic Al, oyster tissue, pine needles, plant leaves, rice and wheat flours and zinc-Al alloys. Bone meal, bovine liver and muscle powder, a milk powder, and urine with non-certified Al values were available. 

The determination of silicon is complex, and a number of factors may interfere with its measurement. The element s concentration is mostly assessed in serum or urine, but to what extent these parameters are reliable indices of the total body burden is not yet clear. Moreover, until now no certified reference material is available. Hence, the availability of standardized techniques and methods that attain a sufficiently good analytical performance to allow accurate and precise analysis of biological fluids is mandatory. 

Certified reference materials are commercially available for total arsenic concentrations in e.g. water, bovine liver, some plant materials, various environmental materials, oyster tissue, albacore tuna, mixed diets, milk powder and urine (LGC, 1992) but no materials are yet available with certified amounts of arsenic species. However, work is under way at... 

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