离心沉淀气相色谱法测定面粉中过氧化苯甲酰含量的研究

建立了离心沉淀，气相色谱氢火焰离子化检测器测定面粉中过氧化苯甲酰含量的方法。考察了不同提取时间和采用不同工作曲线对过氧化苯甲酰测定的影响。试样在石油醚中被冰乙酸还原成苯甲酸，经HP-5（30m×0．25mm×0．25μm）毛细管气相色谱柱分离，氢火焰离子化检测器测定。方法的线性范围为0．005～0．08g／L（r=0．9992），检出限（S／N=3）为2mg／kg。在添标水平为0．06、0．18和0．30g／kg时的平均回收率为82．70％～89．46％，相对标准偏差为3．77％～6．93％。该方法仪器设备简单，测定结果灵敏、准确，适合面粉中过氧化苯甲酰的测定。

Determination of Benzoyl Peroxide in Wheat Flour by Gas Chromatography after Precipitation by Centrifugation

An analytical method of gas chromatography with flame ionization detection after precipitated by centrifugation was established for determination of benzoyl peroxide in wheat flour. The effects of different extraction time on the extraction efficiency and different calibration strategies for quantification were investigated, respectively. The benzoyl peroxide which was extracted from wheat flour with petroleum ether(60～90℃) was converted to benzoic acid in acidic condition, and then analyzed by gas chromatography with flame ionization detection. Recovery studies were performed at 0.06,0.18 and 0.30 g/kg fortification levels and the recoveries obtained ranging from 82.70% to 89.46% with relative standard deviations ranging from 3.77% to 6.93%. The method showed good linearity over the range assayed of 0.005～0.08 g/L and the detection limit was 2 mg/kg. The proposed method was suitable for determining benzoyl peroxide in wheat flour with high sensitivity, good accuracy and low-cost.