分级制备法评估粉碎粒径对玉米中黄曲霉毒素B_(1)测定的影响

Effect of Grinded Particle Size on the Determination of Aflatoxin B_(1) in Maize Evaluated by Fractional Preparation Method

评估粉碎粒径对黄曲霉毒素B_(1)(AFB_(1))测定的影响,改进样品制备方法,提高现行国标检测方法对玉米原粮样品AFB_(1)测定结果的重复性。以天然AFB_(1)阳性玉米为实验材料,采用分级制备方式得到不同粒径范围的四个级别样品,使各级样品的粒径分布差异最大化,通过各级别样品中AFB_(1)测定值及变异系数评估样品制备对AFB_(1)测定值的影响,得到最佳样品制备要求和称样量,进行验证。样品粉碎后的不同粒径样品与该部分的AFB_(1)含量成反比;当称样量为5 g时,应将样品粉碎至全部通过0.6 mm网筛;当称样量为10 g时,应将样品粉碎至全部通过0.9 mm网筛,以使检测结果重复性符合GB/T 32465—2015《化学分析方法验证确认和内部质量控制要求》的要求。研究结果兼顾AFB_(1)测定准确性与操作效率,可扩大应用于其他真菌毒素的检测,对完善食品中真菌毒素检测方法具有参考意义。

To evaluate the influence of grinded particle size on the determination of aflatoxin B_1(AFB_1),improve the sample preparation method and the repeatability of the current national standard detection method for the determination of AFB_(1) of corn raw grain samples,this study uses natural AFB_1-positive corn as experimental material,and four grades of samples with different particle size ranges were obtained by means of graded preparation,so as to maximize the differences of particle size distribution of samples at all levels.The influence of sample preparation on AFB_(1) determination values was evaluated by AFB_(1) determination values and coefficient of variation in samples of all levels,and the optimal sample preparation requirements and sample size were obtained and verified.The AFB_(1) content of different particle size samples was inversely proportional to that of the sample after grinding.When the sample weight is 5 g,it should be crushed until all through the 0.6 mm sieve.When the sample weight is 10 g,it should be crushed until all through the 0.9 mm sieve,so that the test results meet the requirements of GB/T 32465—2015《Requirements for verification & validation of detection methods and internal quality control on chemical analysis》.The results give consideration to the determination accuracy and operation efficiency of AFB_1,which can be applied to the detection of other mycotoxins and has important significance for improving the detection methods of mycotoxins in foodstuff.