Links water samples

Mass speetrometry has been used to eharaeterize mieroeystins using the method of fast-atom bombardment (FAB) ionization and MS/MS. Anatoxin-a has been analysed by MS in eombination with gas ehromatography in bloom and water samples, and in benthie eyanobaeterial material and stomaeh eontents of poisoned animals.Reeently, liquid ehromatography (LC) linked to MS has been employed to analyse mieroeystins, where FAB-MS and atmospherie-pressiire ionization (API-MS) have been used, and anatoxin-a, where thermospray (TSP-MS) was iised. ... 

SPE methods with different cartridge packings have been employed for the pre-concentration and clean up of sulfonated azo dyes from waters and soil extracts [110,111], The extraction of solid samples has been carried ont by sonication or Soxhlet extraction and the extracts treated like the water samples. C18 cartridges and columns [111] were used followed by the elution with aqueous organic solvents in the presence of TEA with recovery yields always greater than 65% [93,111], Higher recoveries have been obtained by using C18 columns, pre-conditioned with an ammonium acetate buffer and elnted with methanol [111], The use of styrene-divinylbenzene [93,112], as well as of cross-linked polymeric sorbents with sulfonate functions, was shown to be suitable in the SPE of the more polar componnds [111],... 

Rubio, F.M., J.A. Itak, A.M. Scutellaro, M.Y. Selisker, and D.P. Herzog (1991). Performance characteristics of a novel magnetic-parti-cle-based enzyme linked immunosorbent assay for the quantitative analysis of atrazine and related triazines in water samples. Food Agric. Immunol., 3 113-125. 

Farre, M., M. Kuster, R. Brix, et al. 2007. Comparative study of an estradiol enzyme-linked immunosorbent assay kit, liquid chromatography-tandem mass spectrometry, and ultra performance liquid chromatography-quadrupole time of flight mass spectrometry for part-per-trillion analysis of estrogens in water samples. J. Chromatogr. A 1160 166-175. 

Cespedes, R., K. Skryjova, M. Rakova, et al. 2006. Validation of an enzyme-linked immunosorbent assay (ELISA) for the determination of 4-nonylphenol and octylphenol in surface water samples by LC-ESI-MS. Talanta 70 745-751. 

Abad, A. and A. Montoya. 1997. Development of an enzyme-linked immunosorbent assay to carbaryl. 2. Assay optimization and application to the analysis of water samples. J. Agric. Food Chem. 45 1495-1501. 

Schraer, S.M., D.R. Shaw, M. Boyette, et al. 2000. Comparison of enzyme-linked immunosorbent assay and gas chromatography procedures for the detection of cyanazine and metolachlor in surface water samples. J. Agric. Food Chem. 48 5881-5886. 

Methods for Determining Biomarkers of Exposure and Effect. No biomarker has been identified that can be quantitatively related to dinitrophenol exposure (see Section 2.5.1) however, the presence and the amount of 2,4-DNP and 2-amino-4-nitrophenol, a metabolite in the urine, can be used as rough indicators of the intensity of exposure (see Section 2.5.1). The methods presently available for determining 2,4-DNP and 2-amino-4-nitrophenol (diazotization) in urine are outdated (Gisclard and Woodward 1946). An enzyme-linked immunosorbent assay (ELISA) is available for the quantitation of 2-amino-4-nitrophenol in water samples, but is not effective in urine (Li et al. 1991). It would be useful to develop an updated routine method for determining 2,4-DNP, 2-amino-4-nitrophenol, and 4-amino-2-nitrophenol in urine with well-defined detection limits, precision, and accuracy. 

Subsequent studies90 focused on the population structure of fish presenting tumors as well as the role of heavy metals. Overall neoplasm prevalence appears to be stable at about 22% of the population. No juvenile fish, out of 2000 + examined, exhibited tumors. Likewise, tumor prevalence did not appear to be seasonal or site specific within the Lake of the Arbuckles. Water, sediment and fish tissues were collected from the Lake of the Arbuckles, a reference lake outside the drainage, and were analyzed for total recoverable metals (cadmium, chromium, copper, nickel and lead) by graphite furnace atomic absorption. Chromium, copper and nickel were found in the water samples at concentrations of > 1 — 8.6 /xg/1. Low concentrations (>1-13.6 /xg/g wet weight) of all the metals were found in the sediment and liver tissues from both sites. Based on these concentrations, heavy metal contamination does not appear linked to neoplasm occurrence. 

On completion ofthe desired period of cross-linking the sample sandwiched between the two KBr discs is removed from the oven, placed into a beaker containing distilled water (50 ml) and left forthe substrates to dissolve ( 3-4 h). 

The use of immunoassay techniques for the determination of PAHs has been reviewed. Immunoassay is based on the coupling of a specific biological antibody in the detection device with the analyte either directly in water or extracted from solid samples and diluted in buffer solution. Enzyme-linked immunosorbent assay (ELISA) is the most common immunoassay technique employed in commercially available test kits. Water samples or soil extracts are added with an enzyme conjugate reagent to immobilized antibodies where the conjugate competes with PAHs for binding to the antibodies. ELISA test kit sensitivity and crossreactivity depends on the PAH used to raise the antibody. Antiphenanthrene or antffluoranthene antibodies raised in host animals are the most commonly employed. Test kits will be most sensitive to the PAH from which the antibody was... 

Several SP materials have been used for the extraction of FRs from aqueous samples, plasma and milk (Table 31.7). Similar materials have been used for all FRs. Typical SP materials include Ci8 and Cg bonded to porous silica, highly cross-linked poly(styrene divinylbenzene) (PS-DVB), and graphitized carbon black (GCB). It is also possible to use XAD-2 resin for extraction of various FRs, pesticides, and plastic additives from large volumes of water (100 1). The analytes can then be either eluted from the resin by acetone hexane mixture, or Soxhlet extracted with acetone and hexane. For a specific determination of diphenyl phosphate in water and urine, molecularly imprinted polymers have been used in the solid phase extraction. The imprinted polymer was prepared using 2-vinylpyridine as the functional monomer, ethylene glycol dimethacrylate as the cross linker, and a structural analog of the analyte as the template molecule. Elution was done with methanol triethylamine as solvent. Also solid phase microextraction (SPME) has been applied in the analysis of PBDEs in water samples. The extraction has been done from a headspace of a heated water sample (100°C) using polydimethylsiloxane (PDMS) or polyacryl (PA) as the fiber material. ... 

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