高效液相荧光法测定“北京烤鸭”鸭皮中的多环芳烃

采用气体射流冲击加热新技术烤制“北京烤鸭”，对其烤制过程中可能产生的三种多环芳烃(PAHs)含量进行检测，建立一套适合于烤鸭类高脂肪、高蛋白食品中PAHs 的提取与检测的方法。方法：匀浆鸭皮样品前处理采用2mol/L KOH 甲醇- 水(8:2，V/V)皂化，异辛烷萃取，甲醇- 水(1:1，V/V)洗涤，N,N- 二甲基甲酰胺- 水-异辛烷(1:1:1，V/V)反萃取和Florisil 固相萃取小柱净化，最后进行HPLC 分析。结果：标品实验回收率在83.59%～92.97%，当样品加标水平分别为1、2、2μg/kg 时，回收率在73.85%～80.31%，RSD ＜ 10%，三种PAHs 检测量在0.56～3.19μg/kg。结论：该方法净化效果较好，重现性高，检测灵敏度和准确度均满足分析要求，样品中苯并a]芘的含量远远低于国家规定对烟熏烧烤类食品不能超过5μg/kg 的标准。

Determination of Polycyclic Aromatic Hydrocarbons in Skin of “Peking Roast Duck” by High Performance Chromatography-Fluorescence Detection

In the process of “Peking Roast Duck” with a novel heating technique, namely air jet impingement, polycyclic aromatic hydrocarbons (PAHs) may be formed. A method of HPLC coupled with fluorescence detector was developed for the determination of PAHs in fat- and protein-rich foods, such as “Peking Roast Duck”. Homogenized duck skin samples were pretreated by using methanol containing 2 mol/L KOH-water (8:2, V/V) for saponification, issoctane for extraction, methanolwater (1:1, V/V) for washing, DMF-water-issoctane (1:1:1, V/V) for liquid-liquid partition, and Florisil solid-phase column for cleaning up. Results showed that the recoveries of benzoa]pyrene (Ba]P), dibenzoa,h]anthracene (DBa.h]A) and 7,12- dimethylbenzenea] anthracene (7,12-DMBa]A) in blank sample at the spiked amounts of 2 × 10-8 and 1 × 10-7 g were between 83.59% and 92.97%, and their recoveries at the spiked amount of 1, 2 and 2 μg/kg respectively, were 73.85% to 80.31%, and the RSDs were less than 10%. Their contents in roasted duck ranged from 0.56 to 3.19 μg/kg, but no these three compounds were found in raw duck. Our results suggested the high clean-up efficiency and recovery of this method and the sensitivity and accuracy of detection could meet the requirements for analysis of trace compounds in complex matrices. The Ba]P content of 0.56 μg/kg is far less than the maximum limit value of 5 μg/kg in the smoked and roasted foods in term of the national standards.