H. Obana et al., DETERMINATION OF ACEPHATE AND METHAMIDOPHOS IN FOODS USING SUPER-ABSORBENT POLYMER, Analytical communications, 34(9), 1997, pp. 253-256
The water-soluble pesticides acephate and methamidophos were extracted
from comminuted vegetables after their juice was absorbed by super-ab
sorbent polymer particles. Food homogenate (10 g) was mixed with 5 g o
f polymer, and the mixture was extracted with 75 mi of ethyl acetate u
sing a high speed homogenizer, The extracts were cleaned up by a silic
a gel mini-column and determination was by GC-FPD. This extraction pro
cedure was compared with the Japanese official method in which samples
were dehydrated with 75 g of anhydrous Na2SO4 and extracted with ethy
l acetate, Unlike that of anhydrous Na2SO4 our mixture of sample and p
olymer was not bulky, nor did it harden. Recovery tests in seven veget
ables at the 0.1 ppm level showed that recovery rates with polymer deh
ydration were usually more than 80% for both pesticides with <10% prec
ision, The two extraction procedures detected similar pesticide levels
in pesticide-containing vegetables. These findings revealed that the
inexpensive super-absorbent polymer can be used in residual analysis o
f acephate and methamidophos in foods in place of bulky anhydrous Na2S
O4.