Oyster tissue

Season of collection (Fowler and Oregioni 1976 Sanders etal. 1991) and latitude (Anderlini 1974) also influenced silver accumulations. Seasonal variations in silver concentrations of Baltic clams (Macoma balthica) were associated with seasonal variations in soft tissue weight and frequently reflected the silver content in the sediments (Cain and Luoma 1990). Oysters from the Gulf of Mexico vary considerably in whole-body concentrations of silver and other trace metals. Variables that modify silver concentrations in oyster tissues include the age, size, sex, reproductive stage, general health, and metabolism of the animal water temperature, salinity, dissolved oxygen,... 

Due to false positives, zinc may confound interpretation of the paralytic shellfish poisoning (PSP) mouse bioassay, one of the routine tests used to measure shellfish safety for human consumption. For example, mice injected intraperitoneally with extracts of healthy oyster tissues showed extreme weakness, a drop in body temperature, cyanosis, and some deaths (McCulloch et al. 1989). The threshold for a toxic PSP response corresponds to a drained tissue zinc level >900 mg/kg FW, and this overlaps the zinc concentration range of 230 to 1650 mg/kg FW (1900 to 9400 mg/kg DW) recorded in healthy oyster soft tissues (McCulloch et al. 1989). 

Mayer, F.L., Jr., and M.R. Ellersieck. 1986. Manual of acute toxicity interpretation and data base for 410 chemicals and 66 species of freshwater animals. U.S. Fish Wildl. Serv., Resour. Publ. 160. 579 pp. McCulloch, A.W., R.K. Boyd, A.S.W. de Freitas, R.A. Foxall, W.D. Jamieson, M.V. Laycock, M.A. Quilliam, J.C. Wright, V.J. Boyko, J.W. McLaren, M.R. Miedema, R. Pocklington, E. Arsenault, and D.J.A. Richard. 1989. Zinc from oyster tissue as causative factor in mouse deaths in official bioassay for paralytic shellfish poisoning. Jour. Assoc. Offic. Anal. Chem. 72 384-386. 

Marcus, J.M. and T.P. Stokes. 1985. Polynuclear aromatic hydrocarbons in oyster tissue around three coastal marinas. Bull. Environ. Contam. Toxicol. 35 835-844. 

As shown in Table 12.17, complete recovery of added arsenic was obtained within experimental error for a sediment. The arsenic concentration obtained by replicate analysis of the orchard leaves (9.7 0.3pg gr1) and oyster tissue (13.2 0.4pg g-1) were in agreement with the certified values of 10 2 and 13.4 1.9pg gp1, respectively. 

Recently, Sakai et al. have combined flame Zeeman atomic absorption spectrometry (FZAAS) with selective vapourisation of the spaaes from a sample, placed in a crucible which is slowly heated, to investigate the speciation of arsenic compounds in oyster tissue. This method could prove useful if the top temperature reached by the system is high enough to allow the vapourisation of a wider variety of species that may exist in biological samples. Presently, the highest temperature attainable is 400 °C. 

In a summary of 1975-1979 data on fish tissue from EPA s STORET database, the mean concentration of silver in 221 samples was 0.225 mg/kg (wet weight total fish), with a range of 0.004-1.900 mg/kg (Scowetal. 1981). In Lake Pontchartrain, Louisiana (which is likely to receive substantial inputs of metals from municipal and agricultural activities) silver concentrations in clams and American oyster tissues were 0.4-2.4 mg/kg and 5.5 mg/kg (all dry weight), respectively (Byrne and DeLeon 1986). 

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. 

CRMs bovine liver, oyster tissue, total diet, whole egg powder... 

The CRM NIST SRM 1568a Rice Flour, along with the CRMs NIST SRM 1566 Oyster Tissue, 1567 Wheat Flour, and 1570 Trace Elements in Spinach, was revalidated nearly two decades after the original certification was issued [29]. 

Sonication with a waterD methanol solution is the most popular method for the extraction of As species from rice powder [24, 25], algae, chicken meat [26], oyster tissue [27, 28], and baby foods [29]. Sample treatment with triBuoroacetic acid at 100°C was reported to be an efficient method for the extraction of As species present in different food matrices when compared with alternative methods that included sonication and accelerated solvent extraction. Extraction recoveries from 94 to 128 percent were obtained [29]. Low-molecular-weight Se compounds were extracted from nuts with HCIO4 to produce a fraction containing 3 to 15 percent of the total Se in different types of nuts [30]. 

Figure 16.4. HPLC-ICPMS chromatogram of oyster tissue (1) arsenite (2) unknown (3) MMADPQ-arsenosugar (4) DMA (5) S04-arsenosugar (6) arsenate (7), (8) and (9) unknown (10) OH-arsenosugar (11) unknown (12) arsenobetaine (13) TMAO (14) arsenocholine (15) TMAs (courtesy of Dr Ute Kohlmeyer, GALAB Laboratories, Geesthacht).

A. Chatterjee, Determination of total cationic and total anionic arsenic species in oyster tissue using microwave-assisted extraction followed by HPLC-ICP-MS,... 

M. Vilano, R. Rubio, Determination of arsenic species in oyster tissue by microwave-assisted extraction and liquid chromatography-atomic fluorescence detection, Appl. Organomet.Chem., 15 (2001), 658-666. 

Daskalakis KD. 1996. Variability of metal concentrations in oyster tissue and implications to biomonitoring. Mar Pollut Bull 32 794—801. 

Oyster Tissue Wheat Flour Rice Flour Brewers Yeast Spinach Orchard Leaves Tomato Leaves Pine Needles Bovine Liver... 

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