Determination of aflatoxins in medicinal herbs by high-performance liquid chromatography-tandem mass spectrometry.
BACKGROUND
We report a rapid and accurate method to determine the natural occurrence of aflatoxins (AFs) B1, B2, G1 and G2 in medicinal herbs and the analysis of 174 commercial samples by this method.


OBJECTIVE
The aim of the present work is to examine the occurrence of the aflatoxins B1, B2, G1 and G2 in common medicinal herbs.


METHODS
The AFs were extracted, purified by immunoaffinity column and analysed by high-performance liquid chromatography-tandem quadrupole mass spectrometry with electrospray ionisation (HPLC-MS/MS).


RESULTS
The AFs can be separated within 6 min using an Agilent XDB C₁₈-column. The target analyte AFB1 could be detected at 0.14 µg/kg. A good linear relationship was found for AFG1 and AFB1 in 1-100 pg and AFG2 and AFB2 in 0.8-30 pg (r > 0.9995). The analyte recovery under three different spiking levels was 64-100% with the relative standard deviations (RSD) below 8.19%.


CONCLUSIONS
This simple and accurate method effectively eliminates false positive detection and can be used to determine the AFs in medicinal herbs to control product quality. We found that in the 174 samples tested, 27 were contaminated with AFs. The incidences of AFB1, AFB2, AFG1 and AFG2 in the samples tested were 15.52%, 14.37%, 6.32% and 2.30%, respectively. We proposed 10 µg/kg total AFs and 5 µg/kg AFB1 as the reasonable maximum limits (ML) in medicinal herbs, and there are 10 samples (5.71% occurrence) in our test that exceeded this proposed limit.
National Institutes for Food and Drug Control, Beijing 100050, China.
Lina
L
Liu
Hongyu
H
Jin
Lei
L
Sun
Shuangcheng
S
Ma
Ruichao
R
Lin
D016604:Aflatoxin B1 / Q000737:chemistry / Q000302:isolation & purification*; D000348:Aflatoxins / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D004340:Drug Contamination; D007118:Immunoassay / Q000379:methods; D016014:Linear Models; D019684:Magnoliopsida / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry* / Q000382:microbiology; D027343:Rhizome / Q000737:chemistry; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods / Q000592:standards; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards; D013997:Time Factors
D000348:Aflatoxins; D010936:Plant Extracts; C027955:aflatoxin G1; C029754:aflatoxin G2; C029753:aflatoxin B2; D016604:Aflatoxin B1