Modification of AOAC multiresidue method for determination of synthetic pyrethroid residues in fruits, vegetables, and grains. Part II: Acetone extraction system.
To optimize conditions and to evaluate further a multiresidue method for pyrethroids, various extraction solvents and partitioning conditions were examined. Acetone and acetonitrile (for fruits and vegetables) and acetone-water and acetonitrile-water (for grains) were used as solvents with or without acetonitrile partitioning. Twenty crops fortified with 8 pyrethroid insecticides at low, medium, and high levels were analyzed. For limit of detection (LOD) levels, repeatability tests were completed with acetone-water as extraction solvent. Recoveries of 8 pyrethroid insecticides at LOD levels were 76.2-99.6%, with coefficients of variation (CVs) of 2.08-10.90% for narrow-bore capillary gas chromatography (GC) (n = 6) and 80.1-107.3% with CVs of 3.76-15.38% for wide-bore capillary GC (n = 6). Both acetone or acetone-water extraction with acetonitrile partitioning and acetonitrile or acetonitrile-water extraction with acetonitrile partitioning are suitable for multiresidue analysis of pyrethroid insecticides. However, acetonitrile and acetonitrile-water as extraction solvents were better than acetone and acetone-water at LOD-fortified levels. This finding was confirmed chromatographically with pear, cucumber, and barley control samples.
Pang
G F
GF
Qinhuangdao Import and Export Commodity Inspection Bureau, Hebei, People's Republic of China.
Chao
Y Z
YZ
Fan
C L
CL
Zhang
J J
JJ
Li
X M
XM
Liu
Y M
YM
Zhao
T S
TS
D000096:Acetone; D000097:Acetonitriles; D002523:Edible Grain / Q000737:chemistry; D005504:Food Analysis; D005506:Food Contamination; D005638:Fruit / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007306:Insecticides / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis*; D014675:Vegetables / Q000737:chemistry
D000097:Acetonitriles; D007306:Insecticides; D010573:Pesticide Residues; D011722:Pyrethrins; D000096:Acetone; C032159:acetonitrile