The Detection and Estimation of Part Per Billion Concentrations of Hydrocarbons

The addition of a freeze-out step in liquid nitrogen prior to analysis by gas chromatography with flame ionization detection permits the accurate determination of C₂ and higher hydrocarbons in the part per billion (ppb) range. Concentrations of C₂ and higher hydrocarbons have been measured in commercial cylinders of nitrogen, helium and hydrogen. Using a 150 ml sample of gas, recovery of ppb concentrations is 95 to 100 percent.     

Exhibitors—1967 APCA Annual Meeting

In recent years there has been considerable use of optical observations to determine the aerosol mass loading of the atmosphere. Nephelometer measurements of the scattering coefficient have been used for the local volume mass loading, and the turbidity of the atmosphere determined by the Volz sun photometer has been related to the vertical mass loading. This paper analyses various approaches to measuring the mass loading, and presents improved relationships between the optical observations and the aerosol mass loading.     

Investigation to Determine the Possible Need for a Regulation on Organic Compound Emissions from Stationary Sources in the San Francisco Bay Area

The problem of an investigation of the need for a regulation on organic compound emissions in the San Francisco Bay Area can be divided into two major areas: 1. Is there a need for a regulation on organic compound emissions? What is the extent of photochemical smog effects? How much control is necessary to achieve the desired effects?

2. (2) If the need exists for an organic compound regulation, can a performance type regulation be written for all types of organic compound emissions? Must the regulation be directed toward specific industries or types of emissions? Can the regulation be adequately enforced—both practically and legally?

This paper will describe the studies undertaken by the District Staff to answer the first set of questions. Work covering the second group of questions is now under investigation.