Selective, solid-matrix dispersion extraction of organophosphate pesticide residues from milk.
A rapid procedure has been developed that allows a single-step, selective extraction and cleanup of organophosphate (OP) pesticide residues from milk dispersed on solid-matrix diatomaceous material filled into disposable cartridges by means of light petroleum saturated with acetonitrile and ethanol. Recovery experiments were carried out on homogenized commercial milk (3.6% fat content) spiked with ethanolic solutions of 24 OP pesticides, viz., ethoprophos, diazinon, dimethoate, chlorpyrifos-methyl, parathion-methyl, chlorpyrifos-ethyl, malathion, isofenphos, quinalphos, ethion, pyrazophos, azinphosethyl, heptenophos, omethoate, fonofos, pirimiphos-methyl, fenitrothion, parathion, chlorfenvinphos, phenthoate, methidathion, triazophos, phosalone, azinphos-methyl, at levels ranging for the different OP pesticides from 0.02 mg/kg to 1.11 mg/kg. Average recoveries of four replicates were in the range 72-109% for the different OP pesticides, with relative standard deviations (R.S.D.) from ca. 1 to 19%, while dimethoate and omethoate were not recovered. Coextracted fatty material amounted to an average of about 4.0 mg/ml of milk. The extraction procedure requires about 30 min. The main advantages are that extraction and cleanup are carried out in a single step, emulsions do not occur, several samples can be run in parallel by a single operator, reusable glassware is not needed and simple operations are required.
Di Muccio
A
A
ISS-Istituto Superiore di Sanità (National Institute of Health), Rome, Italy.
Pelosi
P
P
Camoni
I
I
Attard Barbini
D
D
Dommarco
R
R
Generali
T
T
Ausili
A
A
D000818:Animals; D002849:Chromatography, Gas / Q000379:methods*; D007306:Insecticides / Q000032:analysis*; D008892:Milk / Q000737:chemistry*; D009943:Organophosphorus Compounds; D010573:Pesticide Residues / Q000032:analysis*
D007306:Insecticides; D009943:Organophosphorus Compounds; D010573:Pesticide Residues