Accession Number : AD0709609

Title :   A NEW METHOD FOR DETECTING MICRON-SIZED SULFATE AND WATER-SOLUBLE PARTICLES AND ITS USAGE.

Descriptive Note : Research and development technical rept.,

Corporate Author : ATMOSPHERIC SCIENCES LAB WHITE SANDS MISSILE RANGE N MEX

Personal Author(s) : Rinehart,Gayle S.

Report Date : MAY 1970

Pagination or Media Count : 34

Abstract : An easily prepared, chemically sensitive substrate for the detection of soluble micron-sized atmospheric sulfate and certain other water-soluble particles, with a light microscope, was developed. The substrate is made from an aqueous solution of polyvinyl alcohol (PVA), barium chloride, glycerol, and Triton X-100 which is spread on a glass slide and dried. Particles are collected on the slide and then observed under a dark field or phase contrast optical microscope. Under humid conditions, barium chloride reacts with sulfate particles to form PVA-insoluble barium sulfate. This precipitates in a Liesegang ring, while nonsulfate water-soluble components dissolve into the PVA medium. Photomicrography before and after moisture treatment reveals the sulfate and soluble constituents of the particulate sample. The method can be employed to detect sulfate particles as small as 0.3 microns. The number of soluble particles and percent sulfate composition per particle in aerosol samples can be estimated. Comparison of sampled atmospheric aerosol sulfate weight to sulfate weights of similarly unpolluted locations supports the validity of the method. (Author)

Descriptors :   (*FOG, *SULFATES), (*NUCLEATION, FOG), (*DETECTORS, *AEROSOLS), PARTICLE SIZE, AMMONIUM COMPOUNDS, BARIUM COMPOUNDS, CHLORIDES, PHOTOMICROGRAPHY

Subject Categories : Meteorology
      Physical Chemistry
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE