Microporous polytetrafluoroethylene membrane gas-liquid separator for flow injection hydride generation and inductively coupled plasma atomic emission spectrometry

Abstract

The use of a microporous polytetrafluoroethylene (PTFE) membrane as a gas-liquid phase separator in both flow-injection controlled hydride generation and inductively coupled plasma atomic emission spectrometry is described. The major advantages of a microporous PTFE phase separator are fast signal response time (about 3 s), small sample zone dispersion (almost one) and low sample consumption (about 40 µl for one sample injection). The effects of carrier gas flow-rate, sample flow-rate and sample injection time for arsine generation were studied for various microporous PTFE membrances. The precision with a 100 ng ml^–1 As^v solution for six replicate injections was 1–6% for both peak-height and peak-area measurements. The detection limit obtained using peak-height measurements was about 120 pg ml^–1(4.8 pg absolute) and about 25 pg ml^–1 with peak-area measurements (1 pg absolute).