John M. Ruth

Two-Stage, One-Dimensional Thin Layer Chromatographic Method for Separation of Lipid Classes

Abstract A thin-layer chromatographic (TLC) technique was developed for routine analysis of lipid classes of blood, milk, tissue and egg yolk. This procedure provided rapid and reproducible separations suitable for in situ quantitation by densitometry The spotted TLC plate was subjected to two developments in one dimension to separate, in ascending order from the origin: phospholipids, monoglycerides, free fatty acids, cholesterol, 1,2-diglycerides, 1,3-diglycerides, triglycerides, and cholesterol esters. Development 1: chloroform: methanol: acetic acid (98:2:1) to 17.0 cm. Development 2: hexane: ethyl ether: acetic acid (94:6:0.2) to the top of the plate. After air drying, the plate was dipped into a solution of 3% cupric acetate in 8% phosphoric acid for 3 seconds, and heated at 130°C for 30 minutes to char the separated lipid classes. The chromatograms were scanned at 350 nm. Overloading of TLC plates with sample using the spotter resulted in the appearance of distorted kidney-shaped spots. A mathemati...

Oxidative pretreatment accelerates TNT metabolism in soils

The combined effect of ultraviolet (UV)-ozonation (O3) of aqueous 14C-TNT solutions followed by direct addition of the solutions to aerobic soils was examined as a method of disposal. The effect of TNT concentration was studied on both UV-O3 and soil metabolism. The amount of TNT degraded by either process decreased as the concentration increased. UV-O3 of a 1 ppm solution of TNT using a laboratory 450 W lamp for 10, 20, and 30 minutes resulted in substantial fragmentation of the ring and an increase in polarity of the resultant products. Soil metabolism, as measured by metabolic CO2 evolution, increased as the time of prior UV-O3 increased. A large amount of the 14C associated with 14C-TNT recovered from soil was in the non-extractable fraction. When a Pseudomonasputida, adapted to metabolize ortho-nitrophenol or picric acid as a sole source of carbon and nitrogen, was substituted for the soil phase, about 25% of the added 14C appeared as 14CO2. 1,3,5-Trinitrobenzene, 2,4,6-trinitrobenzaldehyde, 3,5-dinitrophenol, 3, 5-dinitrocatechol, 3,5-dinitrohydroquinone, and oxalic acid were identified as products of UV-O3. Rapid destruction of TNT took place in a large 66 lamp unit, and the resultant distribution of 14C was similar to the results from the laboratory studies.

Separation of S-Triazine Herbicides by Countercurrent Chromatography

Abstract Countercurrent chromatography (CCC) has been successfully applied for the separation of four chlorinated s-triazine derivatives, namely, simazine, atrazine, propazine, and trietazine, which are widely used as herbicides. Of several solvent systems investigated, n-hexane-ethyl acetate-methanol-water (8:2:5:5) gave the best range of the partition coefficient values because of the satisfactory solubility for all samples and therefore was used for the separation of s-triazines. Two types of countercurrent chromatographs, high speed CCC, and horizontal flow-through coil planet centrifuge, were used for s-triazines separation, and the identity of the separated fractions was unequivocally established by mass spectrometry. The potential practical application of CCC to herbicide analysis is discussed.

Characterization of two steroidal olefins in nonfat dry milk

Two steroidal olefins were isolated from the hydrocarbon fraction of a n-hexane extract of nonfat dry milk. They were characterized as 24-methyl-Δ2-cholestene (Δ2-campestene) and 24-ethyl-Δ2-cholestene (Δ2-sitostene) by gas chromatography, mass spectrometry, and synthesis.

Di-2-ethylhexyl phthalate in thermally oxidized corn oil

A phthalate ester, recently isolated from thermally oxidized corn oil, has been identified as di-2-ethelhexyl phthalate.

Separation of Pesticides and Impurities by Countercurrent Chromatography

Abstract Countercurrent chromatography (CCC) was chosen for study as an isolation technique for pesticides and the impurities found with them, because its high capacity makes possible comparatively large batches of purified materials and because its mild operating conditions minimize the danger of degradation during the separation. Technical grade fenthion, an organophosphorus insecticide, showed traces of six impurities. The principal one found in an analytical standard fenthion was identified as 3-methyl-4-(methylthio)anisole, well separated from the fenthion. The n-octyl ester of the herbicide 2,4,5-T was easily separated from the methyl ester impurity.