Reference materials liver

Wise SA, Schantz MM, Koster BJ, Demiralp R, Mackey EA, Greenberg RR, Burow M, OsTApczuK P, Lhlestole TI (1993) Development of frozen whale blubber and liver reference materials for the measurement of organic and inorganic contaminants. Fresenius J Anal Chem 345 270-277. 

Table I. Concentration of lead and cadmium and zinc obtained from analysis of blood and liver reference materials ...

Figure 8.35 Time-resolved absorbance spectrum for DOLT-2 Dogfish Liver reference material in the vicinity of the cobalt absorption line at 240.725 nm (a). solubilized in TMAH (b)...

Within collaborative work on element concentrations in a number of biological reference materials using solid sampling and other analytical methods, calibration of Cd, Cu, Pb and Zn in BCR CRM 185 Bovine liver with solid CRMs was performed for each element with a reference material of the same matrix, NIST SRM 1577... 

A wide variety of reference materials is now available, covering several different kinds of natural matrix such as food (e.g. milk powder), human tissues (e.g. liver), marine biological materials (e.g. tuna fish) and soils and sediments. The radionuclides of interest cover naturally occurring ones (e.g. Ra), fission products... 

Accuracy of in vivo and in vitro measurements of americium is determined through the use of standard, certified radioactive sources with known concentrations of americium. The primary source of certified americium standards is the National Institute of Standards and Technology (NIST). Standard solutions are available for241 Am (SRM 4322, 40 Bq/g [1.1 nCi/g]) and 243Am (SRM 4332, 40 Bq/g [1.1 nCi/g]). Standard Reference Materials for human lung (SRM 4351) and human liver (SRM 4352) are also available from NIST. 

Some of the methods commonly used for the determination of thorium in biological materials are given in Table 6-1. The colorimetric methods are not capable of isotope-specific determination of thorium isotopes. Alpha spectrometric and neutron activation analysis are useful in the quantification of isotope-specific thorium and thorium-232, respectively, and have better sensitivities than colorimetric methods. Alpha spectrometry is the commonly used isotope-specific analysis for the determination of thorium-232 and the thorium-230 derived from the decay of uranium-238 (Wrenn et al. 1981). Standard reference materials (SRMs) containing thorium in human liver (SRM-4352) and human lung (SRM-4351) necessary for the determination of absolute recovery in a given sample are available from the National Institute of Standards and Technology (Inn 1987). 

Residue-testing laboratories might also need to review their sample preparation processes and consider modifying or eliminating tissue homogenization prior to residue extraction. Suppliers of proficiency-testing services should also question whether certain drugs are appropriate to include in such studies. For example, liver spiked with sulfaquinoxaline, sulfadiazine, or sulfamerazine is not suitable for preparation of spiked interlaboratory check samples or reference materials. 

A number of reference materials for vitamins in foods are under development. Extensive analysis and stability testing have been conducted to assess the potential of vitamin-enriched milk powder, wholemeal flour, and margarine as well as lyophilized brussels sprouts, mixed vegetables, and pork liver for use as reference materials (193-196). The certification study for vitamin C in the brussels sprouts reference material has been completed. However, methodology problems continue to have a significant negative effect on the development of reference materials. 

Gel permeation chromatography (GPC)/normal-phase HPLC was used by Brown-Thomas et al. (35) to determine fat-soluble vitamins in standard reference material (SRM) samples of a fortified coconut oil (SRM 1563) and a cod liver oil (SRM 1588). The on-line GPC/normal-phase procedure eliminated the long and laborious extraction procedure of isolating vitamins from the oil matrix. In fact, the GPC step permits the elimination of the lipid materials prior to the HPLC analysis. The HPLC columns used for the vitamin determinations were a 10 im polystyrene/divinylbenzene gel column and a semipreparative aminocyano column, with hexane, methylene chloride and methyl te/t-butyl ether being employed as solvent. 

Kidney, liver, femur Microwave digestion with nitric acid addition of internal standard and dilution with eluent SEC/ICP-MS 0.04 g/g 100 14% of spiked Al in reference material Owen et al. 1994... 

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. 

NRCC, Certification Sheet Dogfish Muscle and Liver Certified Reference Materials for Trace Metals, National Research Council of Canada, Ottawa, 1999. 

US Department of Commerce, National Bureau of Standards Certificate of Analysis, Standard Reference Material 1567, Wheat Flour, Washington, D.C., 1978 Standard Reference Material 1568, Rice Flour Standard Reference Material 1570, Spinach Standard Reference Material 1571, Orchard Leaves Standard Reference Material 1573, Tomato Leaves Standard Reference Material 1577, Bovine Liver. 

In past years, on line chromatographic coupling techniques such as HPLC and CE coupled to ICP-MS with the isotope dilution technique have been used for element quantification in speciation analysis. An interesting application of the isotope dilution technique in medical research was proposed recently by Prange and co-workers, who added highly enriched " S, Cu, Zn and Cd spikes to the interface of the CE-ICP-MS system. The authors separated isoforms of metallothionein (e.g., of rabbit liver) by capillary electrophoresis and quantified S, Cd, Cu and Zn concentrations in isoforms by ICP-SFMS using the isotope dilution technique. A new selenized yeast reference material (SELM-1) for methionine, selenomethionine (SeMet) and total selenium content has also certified by an intercomparison exercise. ... 

Table 8. Toxaphene levels reported for the reference material SRM 1588 (cod liver oil). All concentrations in pg/kg... 

These points clearly show the advantages and disadvantages of congener-specific investigations. Furthermore, the validation of analytical methods (sample clean-up and GC quantification) with reference materials is highly advisable. SRM 1588 cod liver oil and the three congeners B8-1413 (P-26), B9-1025 (P-62), and B9-1679 (P-50) should be used for method development. Furthermore, certification of toxaphene levels in more reference materials has to be an important task in the future. 

The cod liver oil reference material was produced by mixing two different previously characterised cod liver oils. The mixing enabled to reach a medium level of OCP contamination, compared to usually analysed samples. 

A number of Standard Reference Materials (SRMs) with certified PCB congener concentrations are available from the National Institute of Standards and Technology (NIST) these include SRM 1588, PCBs in Cod Liver Oil SRM 1939, PCBs in River Sediment SRM 1941, PCBs in Marine Sediment and SRM 1974, PCBs in Mussel Tissue (Schantz et al. 1993a, 1993b). These SRMs are usefial in validating the accuracy of methods for the determination of PCBs, and for verifying that the method remains within acceptable levels of error in during analysis. A summary of available SRMs with certified PCB concentrations is shown in Table 7-4. SRMs with non-certified concentration data for PCBs are included in the table as well. 

Standard reference material (SRM) Materials of known concentration such as those prepared by the National Institute of Standards and Technology (NIST) for example, orchard leaves, bovine liver, oyster tissue, lobster pancreas, steel. 

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. 

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