Acid Hydrolysis Technique Research Articles

Determination of carbofuran and its metabolites

High-performance liquid chromatographic (HPLC) methods for the determination of carbofuran and its metabolites are described. Results obtained for carrot samples by HPLC are compared with those obtained using gas chromatography and nitrogen-specific detection for carbofuran and 3-hydroxy carbofuran and gas chromatography—mass spectrometry with selected ion monitoring for the determination of the three 7-phenol metabolites. The effect upon observed residue levels of conjugate formation by the 3-hydroxy and/or the 7-phenoxy groups of the four metabolites is demonstrated, and appropriate acid hydrolysis techniques are described. Variations in the HPLC parameters for different commodities are presented.

Non-specific incorporation of nucleic acid precursors in Blastomyces dermatitidis and Histoplasma capsulatum.

Incorporation of thymidine, thymidine monophosphate (TMP), thymidine triphosphate (TTP), uridine and orotic acid into DNA, RNA and protein in Blastomyces dermatitidis and Histoplasma capsulatum was studied utilizing a specific acid hydrolysis technique developed for these fungi. Thymidine was incorporated to the greatest extent (approximately 0.5% of added label) followed by uridine, orotic acid, TMP and TTP. In Blastomyces, uridine and orotic acid labeled primarily RNA. TMP and TTP labeled RNA, DNA and protein at nearly the same level. In Histoplasma RNA was labeled poorly by any of these precursors. TMP and TTP labeled DNA predominately and protein to a slightly lower level. Deoxyadenosine or uridine media supplements of 250 micrograms/ml did not enhance incorporation. All precursors tested were found to be nonspecific in that RNA, DNA and protein were labeled. All data indicate that neither RNA nor DNA synthesis can be specifically measured in whole cells or acid precipitates by any of these precursors. Specific radiometric monitoring with these isotopes therefore requires the separation of these macromolecules.

Gas chromatography. A new tool for the analysis of plastics

AbstractIdentification was described by analysis of pyrolysis products, a method which is complicated by the variety of degradation products, but the decomposition products are fairly specific. The pyrolysis technique was used for a quantitative analysis of acrylate and maleate esters in polymers via a hydriodic acid hydrolysis technique. Because of the low volatility of the higher alkyl halides higher esters were saponified at elevated temperatures and the resultant alcohols were chromatographed. Then vinyl acetate was analyzed on the basis of the quantitative yield of acetic acid from polyvinyl acid pyrolysis.

Paper Chromatographic Analysis of Certain Protein Constituents from the House Fly, Musca Domestica Linnaeus1 (Diptera, Muscidae)

Paper chromatographic and acid hydrolysis techniques were used to determine the chemical nature of nine ninhydrin-positive protein constituents from fresh tissue homogenates. The techniques, which are described in detail, included both one-way and two-way chromatograms. The nine constituents found, and/or the amino acids yielded by their acid hydrolysis, were: glutamic acid, serine, and an unknown compound; glutamic acid and alanine; threonine, serine, and beta alanine; aspartic acid and serine; alanine and tyrosine; proline; tryptophan, phenylalanine (?), and valine; methionine and valine. It was concluded that most of the constituents are probably simple peptides (though the Biuret test did not give typical results), and that one constituent is the free amino acid proline.