A Review of:“Lipid and Biopolymer Monolayers at Liquid Interfaces.” K,S. Birdi. Plenum,New York &London, 1989. pp. x + 325. $59.50

A procedure for using a standard image analysis system to assess the dynamic surface tension at air/liquid interface using the oscillating jet method was developed. The application is demonstrated by experimental data obtained from milk and from three different concentrations of commercial nonionic surfactants solutions (Tween 20 and Tween 80) of surface ages from 2 to 9 milliseconds.     

A review of: “Handbook of Derivatives for Chromatography. K. Blau and G. S. King (editors). Heyden Publishers,London, Bellmawr,N.J., Rheine, 1977. xvi f 576 pages. Price £24.00: U.S.A. $48.0: DM 154.00.”

Abstract

Urban particulate matter, collected from Washington, DC and certified by the National Institute of Standards and Technology (NIST) as Standard Reference Material 1649, was extracted and fractionated into acid, base and neutral fractions. Each fraction was tested for biological activity using a microbial mutagenesis assay system. The organic acid fraction showed unexpectedly high mutagenic activity, and was subjected to chemical characterization studies. Following derivatization, analysis by GC/MS showed the presence of fatty acids, aromatic acids (including phenolic compounds), and a significant number of compounds that could not be identified from mass spectral compendia. Spectroscopic and elemental analysis data supported the characterization of the fraction as predominantly aromatic. Mass spectra from both GC/MS and direct probe analysis showed the presence of a chlorinated substance, subsequently identified as the fungicide Dichlorophen. The compound was shown to comprise over 50% of the mass of the organic acid fraction. A reference standard of Dichlorophen was not mutagenic. The presence of the fungicide in the NIST certified urban aerosol is, in all probability, due to artifactual processes. Attempts to concentrate the observed mutagenic activity by preparative chromatography and acid/base partition experiments were not successful.