Enzyme immunoassay chromatographic methods

Johnson and Van Emon [57] have described a quantitative enzyme based immunoassay procedure for the determination of polychlorinated biphenyls in soils and sediments and compared the results with those obtained by a gas chromatographic method. The soil is extracted with methanol, or Soxhlet extracted or extracted with a supercritical fluid. In the case of the latter two extractants good agreement was obtained between immunoassay and gas chromatographic methods. Spiking recoveries from soil achieved ranged from 104% (Aroclor 1248) to 107% (Aroclor 1242). Detection limits were 9pg kg-1 (Aroclor 1245) and 10.5pg kg-1 (Aroclor 1242). Chlorinated anisoles, benzenes or phenols did not interfere. 

Determination of Limonin Content. A summary of the methods reported through 1976 for the quantitative determination of limonin in citrus juices was published previously (3 ) Since then improvements have been made in the high-pressure liquid chromatographic method (44, 45) and advances have been made in the development of enzymatic (46) and immunoassay (47, 48) (see Chapter 15) methods. The latter methods hold great promise for the future. However, in each case the required enzyme or antibody is not yet commercially available. Thus, while substantial progress is being made the need still exists for a simple, sensitive, and rapid commercially available method for routine industrial quality control purposes. 

Y4. Yamamoto, R., Hattori, S., Inukai, T., Matsuura, A., Yamashita, K., Kosaka, A., and Kato, K., Enzyme immunoassay for thyroxine and triiodothyronine in human serum, with use of a covalent chromatographic separation method. Clin. Chem. 27, 1721-1723 (1981). 

Immunoassays offer much potential for rapid screening and quantitative analysis of pesticides in food and environmental samples. However, despite this potential, the field is still dominated by conventional analytical approaches based upon chromatographic and spectrometric methods. We examine some technical barriers to more widespread adoption and utilization of immunoassays, including method development time, amount of information delivered and inexplicable sources of error. Examples are provided for paraquat in relation to exposure assessment in farmworkers and food residue analyses molinate in relation to low-level detection in surface waters and bentazon in relation to specificity and sensitivity requirements built in to the immunizing antigen. A comparison of enzyme-linked immunosorbent assay (ELISA) results with those obtained from conventional methods will illustrate technical implementation barriers and suggest ways to overcome them. 

Modern tHcy methods include enzyme immunoassays and chromatographic-based methods. In practice, immunoassays " are most often used for routine purposes (e.g., fluorescence polarization immunoassay IFPIA] as run on Abbott s IMx and AxSYM platforms) Chromatographic assays include amino acid analysis high-performance liquid chromatography (HPLC) with ultraviolet, fluorescence, or electrochemical detection ° " capillary electrophoresis with fluorescence detection gas chromatography-mass spectrometry (GC-MS) and liquid chromatography with tandem MS (MS-MS). 

See also. Chemiluminescence Oven/iew. Derivatiza-tion of Analytes. Electrophoresis Oven/iew. Enzymes Oven/iew Immobiiized Enzymes Enzyme-Based Eiec-trodes Enzymes in Physioiogicai Sampies Industriai Products and Processes Enzyme-Based Assays. Fluorescence Clinical and Drug Applications. Immunoassays Overview Production of Antibodies. Immunoassays, Applications Clinical Food Forensic. Immunoassays, Techniques Radioimmunoassays Enzyme Immunoassays Luminescence Immunoassays. Mass Spectrometry Polymerase Chain Reaction Products. Nucleic Acids Chromatographic and Electrophoretic Methods Electrochemical Methods. Polymerase Chain Reaction. 

Determination of Serum Antiepileptic Drugs by a New Enzyme Immunoassay Method (MARKIT) in Comparison with Gas-Liquid Chromatographic Method No to Hattatsu 12(6) 485-492 (1980) CA 94 76466t... 

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