Wr. Barrionuevo et Fm. Lancas, Solid-phase microextraction of pyrethroid pesticides from water at low andsub-ppt levels at different temperatures, HRC-J HIGH, 23(7-8), 2000, pp. 485-488
Synthetic pyrethroids are increasingly being used for insect control on fie
ld crops because of their advantageous environmental properties such as sho
rt field life, broad spectrum of insecticide activity, and relatively low m
ammalian toxicity. In the present work, experimental conditions were optimi
zed for trace analysis of pyrethroids in water by using solid-phase microex
traction followed by capillary gas chromatography. Effects of temperature,
SPME-fiber diameter, and matrix were studied. SPME used off-line with a gas
chromatograph electron-capture detection (GC-ECD) showed a linear response
over a wide concentration range. Our results showed a strong temperature e
ffect on pyrethroid extraction yield. The detection limit after 5 min of SP
ME-fiber exposure to the samples changed from 1 ppb (at 30 degrees C) to 0.
1 ppt (at 90 degrees C), which is a 10000 increase in pyrethroid detection.
The standard deviations of the analyte peak area ratios were typically in
the range of 1-7% at 30 degrees C and of 3 to 15% at 90 degrees C. Best con
ditions for pyrethroids analysis were achieved using high temperature solut
ion and a 100 mu m polydimethylsiloxane fiber. No matrix (river water) infl
uence was observed on detection of the investigated pyrethroids.