Improved gas chromatographic method for determination of daminozide by alkaline hydrolysis and 2-nitrobenzaldehyde derivatization and survey results of daminozide in agricultural products.

An improved method was developed for the quantitative determination of daminozide. This new method combines the alkaline hydrolysis and distillation steps of the PAM II method for daminozide with the derivatization, cleanup, and gas chromatographic determination steps of the Wright method for unsymmetrical dimethyl hydrazine (UDMH). The minimum detectable level is 0.05 ppm. Recoveries range from 85 to 110% when daminozide is added at 0.1 to 1.0 ppm, and are generally 40% at the 0.05 ppm level. A variety of domestic and imported products were analyzed by this improved method and daminozide was detected in 33 of the 98 samples analyzed. Levels detected ranged from a trace amount to 0.80 ppm. The identity of UDMH hydrazone was confirmed by mass spectrometry in many samples, thus confirming the presence of daminozide. Two samples containing daminozide were analyzed independently by a second laboratory and the findings were closely duplicated.

Emergence temperature indices and relative retention times of pesticides and industrial chemicals determined by linear programmed temperature gas chromatography.

Emergence temperature indices and relative retention times of nearly 600 pesticides and industrial chemicals are sequentially tabulated to provide a basis for the identification of unknowns detected on methyl silicone columns when programmed temperature gas chromatography is used. A technique of normalizing column parameters is described to enable duplication of the tabulated data on columns which have different dimensions, amount of stationary phase, and/or other operating parameters. Suggestions for enhancing the precision with which these data can be reproduced on other equipment are presented.

Simultaneous parameter compensation in the replication of programmed temperature gas chromatographic retention measurements.

Tables of relative retention times, retention indices or emergence temperatures obtained under one set of chromatographic conditions can be used for the tentative identification of unknowns determined under an entirely different set of conditions. This can be accomplished for a particular liquid phase if the emergence temperature of a reference compound is maintained while one or more chromatographic parameters are changed to compensate for the changes in other parameters. The advantage of using proximal standards for the determination of both relative retention times and emergence temperatures is demonstrated in this report.