HPLC-FLD和GC-MS测定芝麻油中苯并芘的方法比较

Comparison of HPLC-FLD with GC-MS in Estimation of Benzo[a]pyrene in Sesame Oil

在国标GB/T 22509-2008基础上,采用液液萃取-中性氧化铝柱纯化预处理技术,优化测定芝麻油中Ba P含量的HPLC-FLD方法,并从方法学角度比较其与GC-MS方法的适用性。与国标相比,本研究的HPLC-FLD法采用梯度洗脱程序。GC-MS法色谱条件为:HP-5MS毛细管柱(30 m×0.25 mm×0.25μm),梯度升温程序,进样口和传输线温度280℃,脉冲不分流进样,载气流速1.2m L/min。MS条件:EI离子源,离子源230℃,四级杆150℃,选择离子模式(SIM)定量。线性方程分别为Y=817883X+39074(R2=0.9999)和Y=1771.9X-636.6(R2=0.9997);检测限(LOD)分别为0.037和0.062μg/kg;加标回收率分别为82.40%~96.21%和76.21%~94.19%,对应的相对标准偏差(RSD)为3.72%~6.64%和5.18%~7.84%,检测同一芝麻油样品的Ba P含量,前者略大于后者且明显高于国标(P<0.05)。从上述结果得知,两种方法均满足我国对食用油脂中Ba P含量的测定要求,HPLC-FLD法在国标的基础上得到了改善,且方法的准确性:HPLC-FLD法>GC-MS法。

The high-performance liquid chromatography-fluorescence detector(HPLC-FLD) method was optimized to determine benzo[a]pyrene(Ba P) in sesame oil, and its applicability was compared with that of gas chromatography-mass spectrometry(GC-MS) with regard to methodology. Based on the Chinese standard method, GB/T 22509-2008, liquid–liquid extraction and neutral alumina column purification were used for pretreatment. Compared with GB/T 22509-2008, gradient elution was used in the HPLC-FLD method. Chromatographic conditions for GC-MS were as follows: column, HP-5MS capillary column(30 m × 0.25 mm × 0.25 μm); temperature program, gradient; injection port and transfer line temperature, 280 ℃; injection mode, pulsed splitless mode; carrier gas flow rate, 1.2 m L/min. The MS conditions were as follows: ionization mode, electron ionization(EI); temperature of ionization source, 230°C; quadrupole temperature, 150 ℃; with single ion monitoring(SIM) mode for quantitative analysis. The linear equations, limits of detection(LODs), recovery rates, and corresponding relative standard deviation(RSDs) for HPLC-FLD and GC-MS methods were Y = 817883 X + 39074(R2 = 0.9999) and Y = 1771.9X- 636.6(R2 = 0.9997), 0.037 and 0.062 μg/kg, 82.40%~96.21% and 76.21%~94.19%, and 3.72%~6.64% and 5.18%~7.84%, respectively. For the same sesame oil sample, the Ba P content determined by HPLC-FLD was higher than that determined by GB/T 22509-2008 and was significantly higher than that determined by GC-MS(P < 0.05). The results showed that both methods met the requirements for determination of Ba P content in edible oils and fats. The HPLC-FLD method was better compared with GB/T 22509-2008 and its accuracy was greater than that of GC-MS.