A portable data-logging system for industrial hygiene personal chlorine monitoring.

The combination of suitable portable sensors or instruments with small microprocessor-based data-logger units has made it possible to obtain detailed monitoring data for many health and environmental applications. Following data acquisition in field use, the logged data may be transferred to a desk-top personal computer for complete flexibility in manipulation of data and formating of results. A system has been assembled from commercial components and demonstrated for chlorine personal monitoring applications. The system consists of personal chlorine sensors, a Metrosonics data-logger and reader unit, and an Apple II Plus personal computer. The computer software was developed to handle sensor calibration, data evaluation and reduction, report formating and long-term storage of raw data on a disk. This system makes it possible to generate time-concentration profiles, evaluate dose above a threshold, quantitate short-term excursions and summarize time-weighted average (TWA) results. Field data from plant trials demonstrated feasibility of use, ruggedness and reliability. No significant differences were found between the time-weighted average chlorine concentrations determined by the sensor/logger system and two other methods: the sulfamic acid bubbler reference method and the 3M Poroplastic diffusional dosimeter. The sensor/data-logger system, however, provided far more information than the other two methods in terms of peak excursions, TWAs and exposure doses. For industrial hygiene applications, the system allows better definition of employee exposures, particularly for chemicals with acute as well as chronic health effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitoring airborne reactive chemicals by derivatization and high performance thin layer chromatography--anhydrides, acid halides, isocyanates.

A versatile reagent-coated solid sorbent tube has been developed for monitoring airborne reactive chemicals--including acetic anhydride (AcAn), chloroacetyl chloride (CAC), and isocyanatoethyl methacrylate (IEM). The monitoring procedures involve simultaneous collection and derivatization of these chemicals using the reagent 1-(2-pyridyl)piperazine. Following tube/pump sampling, the derivatives are solvent desorbed and analyzed by high performance thin layer chromatography (HPTLC). HPTLC offers high sample throughout chromatographic analyses. The methods are designed to provide accurate time-weighted-average (TWA) and short-term excursion measurements. The reactivity of anhydrides, acid halides, and isocyanates preclude long-term collection without derivatization. Formation of the derivative immediately stabilizes the molecules allowing retention on the solid sorbent. In addition, the derivative allows good chromatography and provides high detection sensitivity. The recoveries for acetic anhydride, chloracetyl chloride and isocyanatoethyl methacrylate are 97.5, 95.2 and 85.0%, respectively. Validation also included the evaluation of humidity effects, storage effects, and potential interferences.

Glycol ethers--validation procedures for tube/pump and dosimeter monitoring methods.

Methods were developed and validated for personal monitoring of exposures to airborne glycol ethers, both short-term and long-term time-weighted-averages. Either a 600 mg charcoal tube or a 780 mg silica gel tube is recommended for monitoring nine glycol ethers, depending upon the humidity and other organic compounds to be monitored. The charcoal tube allows maximum sensitivity and is unaffected by high humidity conditions. Two-phase solvent desorption with CS2 and water allows aqueous phase recoveries of DOWANOL EM, PM, EE, DM, DPM, and TM glycol ethers. DOWANOL EB, DB and TPM glycol ethers are partitioned between the two layers, necessitating chromatographic analysis of both layers. The silica gel tube method can be used to monitor all nine glycol ethers tested, but is affected by high humidity conditions, resulting in significant breakthrough of the more volatile glycol ethers. The 3M organic vapor monitor can accurately and conveniently determine exposure concentrations for DOWANOL EM, EE, and PM glycol ethers, but sensitivities may be inadequate for sampling periods less than one hour. These methods were validated at levels down to 0.1 times the Dow internal exposure guidelines for those substances with Dow exposure guidelines and well above the current ACGIH and OSHA guidelines. This paper also illustrates validation procedures for tube/pump and dosimeter methods, allowing good definition of method accuracy and precision. Some screening experiments are described for diffusional dosimeters to check the most important parameters in a minimum of time. This methodology will allow assessment of human airborne exposures relative to the new toxicology data available on animals.

Solid absorbent collection and gas chromatographic determination of the propylene glycol butyl ether esters of 2,4,5-T in air.

A method has been developed and validated for the collection of the propylene glycol butyl ether esters of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in air and their determination by gas chromatography with electron capture detection. The samples are collected on XAD-2 resin, desorbed in diethyl ether prior to analysis. The procedure is designed for industrial hygiene monitoring to provide an accurate 4 hour time-weighted average of the exposure level. Recoveries were found to be 97 +/- 8% (2 sigma) for the propylene glycol butyl ether esters of 2,4, 5-T in the concentration range of 0.70 ppb (v/v) to 5.00 ppm (v/v). Breakthrough concentrations, storage effects and humidity effects were also investigated.

Gas-liquid chromatographic determination of chlorinated benzenes and phenols in selected biological matrices.

The determination of higher chlorinated benzenes and chlorinated phenols at parts per billion or parts per million levels in biological samples is described. The method includes sulfuric acid digestion, silica gel column chromatography, methylation, alumina column chromatography, and detection by electron capture gas chromatography. Recoveries are reported for fish flesh, rabbit tissues, and duck tissues with detection limits of 10--15 ppb (nb/g tissue).