COMPARATIVE-EVALUATION OF DIFFUSIVE AND ACTIVE SAMPLING SYSTEMS FOR DETERMINING AIRBORNE NICOTINE AND 3-ETHENYLPYRIDINE

A diffusive (or passive) sampling device (PSD) was constructed and evaluated for determining nicotine and 3-ethenylpyridine in environmental tobacco smoke (ETS). The PSD, capable of sampling in either a single-face or dual-face mode, employs a Teflon membrane filter as windscreen and a sodium bisulfate-treated glass-fiber filter as collection medium. Analysis of the bisulfate-treated filter is by GC with thermionic-specific detection after extraction in ethanol/water/sodium hydroxide solution and back-extraction in ammoniated heptane using N-ethylnornicotine as internal standard. Recovery of both analytes was found to be dependent on the extractant volume and extracting time. PSD sampling rate was determined to be 31.5 mL/min for nicotine and 27.8 mL/min for 3-ethenylpyridine (single-face exposure). Nicotine results were equivalent among this passive sampler, active sampling employing sodium bisulfate-treated filters, and active sampling employing collection on XAD-4 resin (AOAC and ASTM official methods). However, active sampling with bisulfate-treated filters was found to be unsuitable for 3-ethenylpyridine determination. Precision among sampler types was 4-5% for active sampling and 10-12% for passive sampling. Detection limits were comparable between the active sampling methods. Although higher for passive sampling, due to lower sampling rates, detection limits are compatible with sample collection times of at least 8 h in indoor environments. Passive sampler exposure times of up to 5 days have been validated.