Homogenization extraction

Liver Addition of water to sample followed by homogenization extraction with benzene, clean-up on silica column and HPLC GC/ECD No data No data Demeter and Heyndrickx 1979... 

After sampling, homogenization, extraction, cleanup, concentration and possible derivatization, use a suitable determination method which provides sufficient selectivity or specificity and sufficient sensitivity. 

Sample preparation consists of homogenization, extraction, and cleanup steps. In the case of multiresidue pesticide analysis, different approaches can have substantially different sample preparation procedures but may employ the same determinative steps. For example, in the case of soil analysis, the imidazolinone herbicides require extraction of the soil in 0.5 M NaQH solution, whereas for the sulfonylurea herbicides, 0.5M NaOH solution would completely decompose the compounds. However, these two classes of compounds have the same determinative procedure. Some detection methods may permit fewer sample preparation steps, but in some cases the quality of the results or ruggedness of the method suffers when short cuts are attempted. For example, when MS is used, one pitfall is that one may automatically assume that all matrix effects are eliminated because of the specificity and selectivity of MS. 

Rainbow trout and channel catfish were exposed to a nominal concentration of 0.02 mg/L of niclosamide for a period of approximately 12 h. Samples of fillet tissue were collected from each fish species before treatment and at 6, 12, 18, 24, 48, 96, and 192 h after exposure. The fish were dissected, homogenized, extracted, and analyzed by HPLC [75],... 

GC/ECD and GC equipped with a microcoulometric detector have been used to determine heptachlor and heptachlor epoxide in a variety of human tissues, including the liver, brain, adrenals, lungs, heart, kidneys, spleen, and pancreas (Curley et al. 1969 Klemmer et al. 1977 Radomski et al. 1968). Details of a sample preparation method were not reported for GC equipped with a microcoulometric detector (Curley et al. 1969). Sample preparation steps for GC/ECD include homogenization, extraction with petroleum ether or hexane, usually followed by a clean-up procedure (Klemmer et al. 1977 Radomski et al. 1968). Recovery, sensitivity, and precision data were not reported (Curley et al. 1969 Klemmer et al. 1977 Radomski et al. 1968). 

Homogenize. Extract with hexane containing anhydrous sodium sulfate. Evaporate. Redissolve in hexane. Clean-up on Florisil. 

PBDEs PBDEs Chicken fat Homogenization, extraction Gas Chromatography Magnetic <1 pg/kg [37]... 

Animal Homogenize extract with GC/MS (NCI) 10 ng/kg No data Jansson et al. 1991... 

Apples, pears Homogenized, extraction with chloroform, 0.1 M HC1, neutralized Na2C03, extraction chloroform HPTLC NH2 plates deriva-tized with propylamine, Supelco LC 18 Chloroform-cyclohexane-methanol (6.0 1 0.1), methanol-phosphate buffer (pH 6.6) (56 44) UV 285 nm UV 280 nm 48... 

The milk/tissue sample was homogenized/extracted with Mcllvaine-EDTA buffer (pH 4.0). The pellet was resuspended and extracted again. The combined extracts were further filtrated on a paper disk to remove any solid particles that might result in the plugging of an SPE cartridge. The extract was loaded on a preconditioned SPE cartridge (with MeOH and water), and TCs were eluted with 10 mM oxalic acid solution in MeOH. 

Extraction of solid samples Homogenization extractions Sonication extractions Microwave assisted extractions Soxhlet extractions Accelerated solvent extractions Supercritical fluid extractions Extraction of liquid samples Liquid-liquid extractions Solid phase extractions (SPE)... 

Tomato K-(di)- glycosides, R Freeze-dried, pulverization, homogenization, extraction with aqueous MeOH, filtration or centrifugation, SPE with polyamide C-18 ACN-H20- THF-TFA H PLC/DAD/MS/MS/ ESI(+), HPLC/NMR 37... 

Animal tissues (Multi-residue method) homogenize extract with n-hexane-acetone treatment with sulfuric acid gel permeation chromatography chromatography or silica gel chromatography or activated charcoal GC/MS (NCI) 10 ng/kg [37]... 

Should the sample be solid, then the first step would involve the extraction of the sample with an appropriate solution that would solubilize the compound of interest and remove as few interfering compounds as possible. This operation is sometimes conducted using a blender or other mixer to provide as homogeneous extract as possible. 

Samples of papaya fruit (C. papaya, L.) were prepared by the scheme shown in Figure 1, which involves direct extraction of the fruit (7j. In a typical experiment 0.7 kg of peeled papaya fruit (seeds removed) were homogenized, extracted and concentrated to produce the sample which was subjected to HRGC and HRGC-MS analysis. 

Freeze drying, sieving and homogenization extraction with methylene chloride clean-up on silica gel followed by sephadex column... 

Tissue (congener specific) Homogenized extracted in methylen chloride hexane (1 1) using Soxhiet extractor cleanup using sulfuric acid and chromatoaraohv HRGC/HRMS See Table 7-1 No data EPA 1999k (method 1668)... 

Liver and adipose tissue of gray seal (methyl sulfone metabolite) Homogenization extraction with methylene chloride/cyclohexane removal of lipids by dialysis cleanup by gel permeation chromatography fractionation on carbon and Florisil columns HRGC/ECNI/MS No data No data Buser et al. 1992... 

The glucuronide metabolite of AZT was isolated from rat and human liver microsomal incubations (177), and the formation of a toxic metabolite of AZT was demonstrated in rat hepatocytes and liver microsomes (177). The metabolism of tamoxifen was examined in human liver homogenate and human Hep G2 cell line preparations by LC/API/MS (178). Several metabolites were detected in the human liver homogenate extracts, namely, N-didesmethyltamoxifen, a-hydroxy-tamoxifen, 4-hydroxytamoxifen, N-desmethyltamoxifen, and tamoxifen N-oxide. All of these metabolites, except the N-didesmethyltamoxifen, were observed in the samples after incubating tamoxifen with the human Hep G2 cell line. In-vitro studies have also used MS to examine potential drug-drug interactions. For example, (179) demonstrated that the a2-agonist, dexmedetomidine, inhibited metabolism of the anesthetic alfentanil, whereas clonidine had no effect. 

The earthworm, commonly used for medicine, is L. rubellus. Mihara isolated and obtained three fractions (F-I, F-II and F-III) of fibrinolytic enzymes, from the homogenized extract [1,3,4]. Six isozymes were identified according to their further purification [24]. F-I and F-III could be subdivided into three (F-I-0, -1-1, and -1-2) and two (F-III-1 and -III-2) components, respectively, except F-II. The molecular mass of each isozyme (monomer) has been measured by several methods (Table 1.). The isoelecctric point (pi) analysis displays weak acids of these isozymes. The biological functions (F-II and F-III-1) maximally exhibit around pH 9.0 at 50°C [7],... 

In homogeneous extractions. I m = T at equilibrium. If Im < I m Oie solute is not soibed selectively by the marc, X Consequently, ilf - 1/. Af usually remains Ouriy constant duiii teaching processes, but m varies somewhat because the density of the occluded and external solutions change as x changes. 

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