Urine hexane extract

To 100-gram batches of 1-day-old samples of cow s urine were added 0.05, 0.1, and 0.5 mg. of Compound 118 in acetone to give 0.5, 1.0, and 5.0 p.p.m., respectively. The urines were then extracted with two 50-ml. batches of hexane. Occasional emulsions were broken by centrifuging. The hexane extracts were dried with anhydrous sodium sulfate, filtered, evaporatively concentrated, and analyzed for Compound 118 as described under Procedure. The results of these analyses are shown in Table IV. Similar experiments with human urine gave slightly better recoveries. 

A 4 ml sample of milk was hydrolyzed and extracted according to the urine procedure. The hexane extract residue was dissolved in 2 ml methanol and centrifuged at ambient temperature, removing white lipid material. The methanol was evaporated under nitrogen and the residue reconstituted in 50 pi hexane. 

The 215nm chromatograms of the pre- and post-drug hexane extracts equivalent to 5 mg creatinine (29 ml urine) are shown in Figure 2. In the 5%B/min.water - acetonitrile gradient, available standards ranging from the relatively polar A9-THC-ll-oic acid to the nonpolar A9-THC eluted between -10-14 minutes (50- 70% acetonitrile). More polar cannabinoids such as hydroxy acids... 

Figure 2. The 215-nm chromatograms of hexane extracts of urine of subject 1, pre- and post-dose. A MicroPak MCH-10 column with 1 mL/min linear gradient program from water - acetonitrile at +5% B/min.

Confirmation of the identity of pentachlorophenol (PCP) in samples of human blood, urine, tissue, clothing, and bedding materials has been reported (II), utilizing combined gas chromatographic-mass spectro-metric analysis of hexane extracts of these substrates. 

B. Urine extraction. Initially the urine was extracted with hexane to remove lipids. The urine pH was then adjusted with HCl to about 5.5 (after this was determined as the pH of optimal maximum extraction) and reextracted using dichloromethane (Table 1)(urine-to-solvent ratio 4 1) in... 

An hplc assay was developed suitable for the analysis of enantiomers of ketoprofen (KT), a 2-arylpropionic acid nonsteroidal antiinflammatory dmg (NSAID), in plasma and urine (59). Following the addition of racemic fenprofen as internal standard (IS), plasma containing the KT enantiomers and IS was extracted by Hquid-Hquid extraction at an acidic pH. After evaporation of the organic layer, the dmg and IS were reconstituted in the mobile phase and injected onto the hplc column. The enantiomers were separated at ambient temperature on a commercially available 250 x 4.6 mm amylose carbamate-packed chiral column (chiral AD) with hexane—isopropyl alcohol—trifluoroacetic acid (80 19.9 0.1) as the mobile phase pumped at 1.0 mL/min. The enantiomers of KT were quantified by uv detection with the wavelength set at 254 nm. The assay allows direct quantitation of KT enantiomers in clinical studies in human plasma and urine after adrninistration of therapeutic doses. 

Urine Acidify and heat to hydrolyze add NaOH extract with anhydrous ethyl ether derivatize with diazoethane concentrate add hexane concentrate and cleanup on silica gel elute with benzene-hexane (PNP) GC/ECD 20 pg/L (20 ppb) 85-98 Shafiketal. 1973b... 

Tributyltin oxide and its metabolites were determined in urine after conversion to chlorides with HC1, extraction with ether containing tropolone (1), conversion to hydrides with NaBFLt, extraction with hexane and GC-AAS end-analysis LOD 1 pg/L for BuSnFL and Bu2SnH2, and 2 pg/L for Bu3SnH87b. 

Urine Extract with hexane successively wash with water, sodium hydroxide, hydrochloric acid, and water GLC/ECD No data >90 Fowler 1969b... 

Some methods are available for determining -hexane in urine and tissues. A modified dynamic headspace extraction method for urine, mother s milk, and adipose tissue has been reported (Michael et al. 1980). Volatiles swept from the sample are analyzed by capillary GC/FID. Acceptable recovery was reported for model compounds detection limits were not reported (Michael et al. 1980). A solvent extraction procedure utilizing isotope dilution followed by GC/MS analysis has been reported for tissues (White et al. 1979). Recovery was good (104%) and detection limits are approximately 100 ng/mL (White etal. 1979). 

Urine (anti- 12-hydroxy- endrin glucuronide) Addition of sodium metaperiodate to urine followed by heating to 70 °C for 45 minutes, addition of carbonate buffer, and extraction with hexane confirmation of analyte by conversion to 12-ketoendrine with chromium trioxide in ovridine GC/ECD No data 92 at 10.5 ppm Baldwin and Hutson 1980... 

Heptachlor, heptachlor epoxide, and their metabolites have been measured in urine and feces using GC/ECD (Tashiro and Matsumura 1978). Sample preparation steps involve extraction with acetone and hexane, clean-up on Florisil and silicic acid columns, and extraction of the derivatized metabolites into hexane for GLC analysis. Precision, accuracy, and sensitivity were not reported (Tashiro and Matsumura 1978). 

Solid-phase extraction for milk, urine, and feces samples is carried out by washing the loaded Cig cartridge successively with 5 ml water, 5 ml acetone/ water (20 80), 5 ml methanol/water (20 80), 5 ml dichloromethane/hexane (20 80), and 5 ml ethyl acetate/hexane (10 90). The corticosteroids are eluted with 3 ml ethyl acetate. The eluate is evaporated, and the residual is reconstituted in 0.5 ml ethanol and 5 ml phosphate-buffered saline, pending subsequent immunoaffinity column cleanup. The solid-phase extraction procedure differs for liver samples. In that case, washing of the cartridge is performed with 5 ml water, 5... 

Most published methods are for analysis of crops and soil residues of the intact acaricides. Extraction has been done by stripping, blender or soxhlet. Extraction solvents have included petroleum ether, benzene, carbon tetrachloride, acetonitrile, diethyl ether, methanol and hexane/acetone. Clean-up steps have em -ployed liquid/liquid partitioning and adsorption on activated charcoal, activated charcoal/Florisil, Florisil, alumina and silica gel. Burke (14) reported that CB is not completely recovered from Florisil. Horn and coworkers (7) found that no clean-up was necessary when analyzing dog urine for CB using a Schecter-Haller procedure. For detection of residues, the colorimetric and UV methods have been replaced by gas chromatographic methods employing microcoulometric or electron capture detectors. 

Figure 2. Distribution according to polarity (extractability of Aa-TIIC) of in vivo metabolites in hydrolyzed and unhydrolyzed Rhesus urine nonpolar neutrals = extractable with hexane at natural pH weakly polar neutrals = extractable with ether at pH 12 weakly polar acids — extractable with ether at pH 2 moderately polar acids = extractable with ethyl acetate at pH 2 highly polar acids = extract-...

ENZYME-HYDROLYZED URINE (pH 5.5) Extract with hexane at pH 8... 

Direct HPLC analysis of urine extracts appears feasible for A -THC. 215nm is the optimum wavelength for detection of THC-class compounds. Dual wavelength at 215 and 280nm serves as a valuable check on cannabinoid retention assignment and as a screen for unknown THC or CBN-class metabolites. The latter feature was demonstrated in the observance of CBN-class peaks in both hexane and E-I extracts. This observation suggests a CBN-metabolic route of A -THC. Evidence of a CBN-metabolic route for A -THC has been reported by McCallum (8) and Green (6) for humans and by Ben Zvi et al (9) for rhesus monkeys. 

Selenium forms a volatile derivative, piazselenol, which can be subjected to GC analysis (Scheme 5.39). Young and Christian [612] treated selenium with 2,3-diaminonaph-thalene at pH 2.0 and extracted the resulting piazselenol into -hexane. With the use of an ECD, down to 5 10-I° g of selenium could be detected. The procedure, applied to the analysis of selenium in human blood, urine and river water, led to results equivalent to those obtained by neutron activation analysis. Similarly, Nakashima and Toei [613] performed the reaction of selenium (as selenious acid) with 4-chloro-o-phenylenediamine at pH 1 and extracted the derivative into toluene. They reported a detection limit of 0.04 jug. Shimoishi [614] analysed the content of selenium in metallic tellurium by this method. The sample was dissolved in aqua regia, followed by reaction with 4-nitro-o-phenylenediamine and extraction into toluene. Down to 10 ng of selenium could be determined using only a few milligrams of sample. Common ions did not interfere even when present in a large excess. Selenium in marine water was determined after the same derivatization step [615],... 

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