Detection chromatography

The method of choice for the determination of a- and P-endosulfan in blood, urine, liver, kidney, brain, and adipose tissue is gas chromatography equipped with an electron capture detector (GC/ECD) (Coutselinis et al. 1976 Demeter and Heyndrickx 1979 Demeter et al. 1977 Le Bel and Williams 1986). This is because GC/ECD is relatively inexpensive, simple to operate, and offers a high sensitivity for halogens (Griffith and Blanke 1974). After fractionation of adipose tissue extracts using gel permeation chromatography, detection limits of low-ppb (1.2 ng/g) were achieved for endosulfan and other chlorinated pesticides using GC/ECD (Le Bel and Williams 1986). 

Mitchell TW, Savage JC, Gould DH. 1993. High-performance liquid-chromatography detection of sulfide in tissues from sulfide-treated mice. J Appl Toxicol 13 389-394. 

Fig. 19.16. Comparative chromatograms with TEA acetate buffer (middle panel) and ammonium acetate (bottom panel). The top panel shows chromatography detected by UV-Vis detection.

Venza and colleagues (2001) applied fluorescence detection using OPA-2-mercaptoethanol to analyze SP, SPD, and PUT in saliva samples using reverse-phase chromatography. Detection hmits reported were 0.04, 0.05, and 0.06 nmol/ml for SP, SPD, and PUT respectively. 

Gas-liquid chromatography detects thienothiophenes in crude Qj]204,2oj gjjjj coffee extract. ... 

Vidrine, D. W. Liquid Chromatography detection using FT-IR in Fourier Transform Infrared Spectroscopy (ed.) Ferraro, J. R., Basile, L. J., Vol. 2, p. 129, New York— San Francisco—London, Academic Press 1979... 

Determination of mandelic acid in urine has been recommended as a biomaiker of exposure to ethylbenzene. Several methods can be used to determine mandelic acid in urine samples. These include derivatization of the acid and GC analysis (detection limit, 1.0 mg/L) isotachophoresis (detection limit, 0.04 mmol/L) and high-performance liquid chromatography (detection limit, 0.01 mmol/L) (WHO, 1996a). 

Imazupyr Methanol None High-performance liquid chromatography, detection at 250 nm [73]... 

Separate by chromatography, detect and analyse spectroscopically or by mass spectrometry. 

Matthees, D.P. and Purdy, W.C., Naphthyldiazomethane as a derivatizing agent for the high-performance liquid chromatography detection of bile acids, Anal. Chim. Acta, 109, 161, 1979. 

Griffin, P., Jones, K., and Cocker, J., Biological monitoring of polychlorinated biphenyls in plasma a comparison of enzyme-linked immunosorbent assay and gas chromatography detection methods, Biomarkers, 2, 193-195, 1997. 

P. E. Nelson, S. L. Nolan, and K. R. Bedford, High-performance liquid chromatography detection of morphine by fluorescence after post-column derivatization, J. Chromatogr., 234 407 (1982). 

Bucholz et al. [91] have described a procedure for the determination of less than 1 pg L 1 of chloride, nitrite and sulphate in 2ml of rainwater sample using non-suppressed ion chromatography. Detection limits are less than 0. lmg L 1 for chloride and nitrate and 0.25mg L 1 for sulphate. The method can accomplish the simultaneous analysis of chloride, nitrate, nitrite and sulphate in less than 25min. 

Amino-terminated telechelic polybutadiene was prepared by LiAlH4 reduction of amidino end-group in polybutadiene, which was polymerised by a water-soluble initiator, 2,2 -azobis(amidinopropane)dihydrochloride. The structure was analysed by 1H- and 13C-NMR, but functionality of 2.0 was obtained by a titration method [70]. Synthesis of co-epoxy-functionalised polyisoprene was carried out by the reaction of 2-bromoethyloxirane with living polymer that was initiated with sec-butyl lithium. The functionality of the resulting polyisoprene was 1.04 by 1H-NMR and 1.00 by thin layer chromatography detected with flame ionisation detection [71]. 

This potency does not account for the inhibition observed for the library Ai (34%, 65,341 compounds), and examination of the various iterations clearly shows other families of active compounds. Nevertheless, a relatively short process (6 iterations, 51 reactions, 37 deprotections, 1 chromatography) detected a reasonably active lead compound as a starting point for chemical optimization. The sublibrary populations were reduced from 65341 to 12 in only four iterations (sublibrary E2, where only 12 permutations of the four monomers in the structure were possible), the second being a control of the validity of the first selection. Deconvolution of a few other families of positives (for example sublibraries Bs, E2, E4 and F2) could have produced different lead structures while maintaining a relatively modest number of iterations and reactions. 

Figure 34. Use of MV +-ZME as an electrode for detection of alkali metal ions in ion-exchange chromatography. Detection using (A) a conductivity detector, (B) an unmodified and (C) Cu-modified ZME. Peaks 1-7 correspond to Li, Na, NH4+, K+, Cs+, Mg + and Ca + respectively.

Also Tojo and Uenoyama (T2) by means of paper chromatography detected neither 5-hydroxyanthranilic acid nor its conjugate forms in urine of senile cataract patients. They found, however, an ethanol-extractable substance giving a positive ninhydrin reaction and Rf value coinciding with that of tryptophan. The oral administration of a dose of anthra-nilic acid did not alter their findings. 

Arsenic(III) and arsenic(V), monomethylarsonate and dimethylarsinate have been determined by differential pulse polarography after separation by ion-exchange chromatography detection limits for the latter two are 18 and 8ppb, respectively. Diphenylarsenic acid has been studied polarographically. ... 

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