中空纤维支撑液膜结合气相色谱测定肉中挥发性脂肪酸

利用中空纤维支撑液膜萃取结合气相色谱测定肉中的挥发性脂肪酸，并建立和验证此方法。中空纤维支撑液膜能够对已酸化的肉浆上清液进行选择性富集。中空纤维管中的萃取物，经盐酸酸化后可直接进行气相色谱分析。此方法线性相关好(r≥0.9261)，检测限较低(0.03～0.16μmol/L)，回收率可接受(71.0%～123.1%)，日内精密度(7.82%～10.28%)和日间精密度(10.01%～15.96%)良好。畜肉中的挥发性脂肪酸含量(725.30～845.23mg/kg)明显高于禽肉中(192.82～282.39mg/kg)。猪肉中总挥发性脂肪酸含量与其pH值呈负相关(r=0.7592)，与挥发性盐基氮负相关良好(r=0.7890)，此结果表明总的挥发性脂肪酸有可能作为肉新鲜度的检测指标。

Determination of Volatile Fatty Acids by Hollow Fiber Supported Liquid Membrane Extraction Coupled with Gas Chromatography

A method for the determination of volatile fatty acids (VFAs) in meat by hollow fiber supported liquid membrane extraction (HF-SLME) coupled with gas chromatography (GC) was developed and validated. HF-SLME was employed to selectively enrich VFAs from the acidified aqueous supernatant of meat homogenate. The extract was further acidified with HCl and analyzed by GC. The proposed method provided high linearity (r≥0.9261), low detection limits (0.03–0.16 μmol/L), acceptable spiked recovery (71.0%–123.1%), and reasonable intra-assay (7.82%–10.28%) and inter-assay (10.01%–15.96%) precision. Total VFAs content in livestock meat (725.30–845.23 mg/kg) are much higher than those from poultry (192.82–282.39 mg/kg). Total VFAs content in pork was negatively correlated with its pH (r=0.7592) and total volatile basic nitrogen (TVB-N) (r = 0.7890). These observations suggest that total VFAs may an indicator of the freshness of meat.