Chromatography, for detection

WA Moats, KL Anderson, JE Rushing, DP Wesen. Comparison of a radioimmunoassay (Charm-II) test with high-performance liquid chromatography for detection of oxytetracycline residues in milk samples from lactating cattle. Amer J Vet Res 56 795-800, 1995. 

DL Roerig, RIH Wang, MM Mueller, DL Lewand, SM Adams. Radioimmunoassay compared to thin-layer and gas-liquid chromatography for detecting methadone in human urine. Clin Chem 22 1915, 1976. 

Kawatsu, K., Shibata, T., and Hamano, Y. 1999. Application of immunoafifinity chromatography for detection of tetrodotoxin from urine samples of poisoned patients. Toxicon 37, 325-333. 

Table 2 An example of headspace GL chromatography for detecting alcohol in body fluids of living and dead persons...

Dugo, G., G. Lamonica, A. Cotroneo, I. Stagno D Alcontres, A. Verzera, M.G. Donato, P. Dugo, and G. Licandro, 1992. High resolution gas chromatography for detection of adulterations of citrus cold-... 

Radioimmunoassay Compared to Thin-Layer and Gas-Liquid Chromatography for Detecting Methadone in Human Urine... 

Gorodetzky, C.W. (1972) Sensitivity of thin-layer chromatography for detection of 16 opioids, cocaine and quinine. Toxicology and Applied Pharmacology, 23,511-518. 

The amino group is readily dia2oti2ed in aqueous solution, and this reaction forms a basis for the assay of sulfas. Aldehydes also react to form anils, and the yellow product formed with 4-(dimethylamino)hen2a1dehyde can be used for detection in thiu-layer and paper chromatography. Chromatographic retention values have been deterrnined in a number of thiu layer systems, and have been used as an expression of the lipophilic character of sulfonamides (23). These values have corresponded well with Hansch lipophilic parameters determined in an isobutyl alcohol—water system. 

Gas-flow counting is a method for detecting and quantitating radioisotopes on paper chromatography strips and thin-layer plates. Emissions are measured by interaction with an electrified wire in an inert gas atmosphere. AH isotopes are detectable however, tritium is detected at very low (- 1%) efficiency. 

For detection residue amounts of tetracyclines in dairy products widely used methods FIPLC, immunoaffinity chromatography, kinetic spectrophotometry, which are expensive and complicated. 

Thermal changes resulting from solute interactions with the two phases are definitely second-order effects and, consequently, their theoretical treatment is more complex in nature. Thermal effects need to be considered, however, because heat changes can influence the peak shape, particularly in preparative chromatography, and the consequent temperature changes can also be explored for detection purposes. 

There are many reports of the use of mass spectroscopy coupled to chromatography outlets for detection and identification of dmgs and metabolites. An example is compound 126 (99MI2, 99MI3). Carboxylic acids have been converted into hydrazides and hence into 3-substituted [l,2,4]triazolo... 

Ion chromatography (IC) is a relatively new technique pioneered by Small et al.25 and which employs in a novel manner some well-established principles of ion exchange and allows electrical conductance to be used for detection and quantitative determination of ions in solution after their separation. Since electrical conductance is a property common to all ionic species in solution, a conductivity detector clearly has the potential of being a universal monitor for all ionic species. 

Detectors. Although electrical conductance has been widely used for detecting ions in ion chromatography, the scope of the technique has been considerably extended by the use of other types of detector. It is convenient broadly to classify detectors into two series. 

Detectors. The function of the detector in HPLC is to monitor the mobile phase as it emerges from the column. The detection process in liquid chromatography has presented more problems than in gas chromatography there is, for example no equivalent to the universal flame ionisation detector of gas chromatography for use in liquid chromatography. Suitable detectors can be broadly divided into the following two classes ... 

This principle also applies to chromatography. For instance, the best of separation methods is of no avail if the results of the separation cannot be detected. 

The primary method for detecting methyl parathion and metabolites in biological tissues is gas chromatography (GC) coupled with electron capture (BCD), flame photometric (FPD), or flame ionization detection (FID). Sample preparation for methyl parathion analysis routinely involves extraction with an organic solvent (e g., acetone or benzene), centrifugation, concentration, and re suspension in a suitable solvent prior to GC analysis. For low concentrations of methyl parathion, further cleanup procedures, such as column chromatography on silica gel or Florisil are required. 

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