Hollow fiber stripping analysis (HFSA), a modification of closed loop
stripping analysis (CLSA), is introduced for the extraction, detection
and identification of trace levels of both volatile and low volatilit
y organic compounds in water. The method uses a bank of microporous hy
drophobic hollow fiber membranes as the air/water contacting device in
a closed, dual-recirculating system. Method design and optimization a
re presented. Application of membrane extraction for detection of tow
nanogram per liter (parts per trillion) concentrations of taste and od
or causing compounds in water is presented. These compounds can be a p
articular problem in water as they are detected by water consumers at
these very low concentrations, and are perceived as being indicative o
f poor water quality. Method detection limits, precision and accuracy
are presented for four known taste and odor causing compounds. HFSA di
splays an advantage over CLSA in detection of lower volatility compoun
ds, and in greater reproducibility. HFSA is also able to avoid foaming
problems that occur in CLSA during analysis of waters with high surfa
ctant concentrations. Higher volatility compounds are detectable at co
ncentrations similar to CLSA. HFSA is shown to be a reliable, precise
and accurate tool for extraction and determination of low nanogram per
liter concentrations of low molecular weight organic compounds with d
imensionless Henry's Law constants down to approximately 0.001 from a
complex natural water matrix. Copyright (C) 1996 Elsevier Science Ltd.