Microporous polytetrafluoroethylene tube separator for the determination of beryllium by flow injection-or suction-flow-solvent extraction followed by inductively coupled plasma atomic emission spectrometry

Abstract

A dual-tube separator was constructed for the purpose of flow injection-or suction-flow-solvent extraction followed by inductively coupled plasma atomic emission spectrometry. It consisted of an inner microporous polytetrafluoroethylene (PTFE) tube (1 mm i.d., 10 cm long, porosity 70%) and an outer PTFE tube (3 mm i.d.). This system was used for the determination of beryllium in alloys by extraction as the acetylacetonate into carbon tetrachloride. The phase separation was complete at an organic flow-rate of 0.2–6.2 ml min^–1 and an aqueous flow-rate of up to 6.2 ml min^–1. With a sample volume of 0.5ml (50 p.p.b. Be) and sample and organic flow-rates of 1.2 and 0.7 ml min^–1, respectively, the relative standard deviation (n= 10) was 1.3% and the sampling rate was 25 h^–1. The sensitivity was enhanced about 2.6-fold compared with that obtained by the direct nebulisation of an aqueous solution.