超声萃取- 气相色谱法测定扇贝中30 种脂肪酸

研究扇贝中脂肪酸测定的前处理技术，建立扇贝中30种脂肪酸(包括饱和脂肪酸、不饱和脂肪酸)的同时测定分析方法。样品经冷冻干燥、超声提取、硫酸-甲醇法甲脂化后，采用气相色谱分析，内标法定量测定扇贝中脂肪酸的含量。正交试验显示，脂肪酸的最佳提取工艺为：溶剂比例为甲醇-二氯甲烷溶液(1:3，V/V)、料液比1:140(mg/mL)、提取3次、每次15min，其中提取次数与溶剂比例对结果影响显著(P＜0.05)。30种不同的脂肪酸在5.0～80.0μg/mL范围内，线性良好，相关系数均大于0.999；不同水平下的加标回收率分别为84%～91%、86%～99%；相对标准偏差(n＝5)分别为1.3%～3.5%、0.9%～3.1%；方法的检出限(RSN＝ 3)为1.94～2.57mg/kg。该方法操作简便、迅速、灵敏、准确度高，可满足扇贝以及类似性质的生物体脂肪酸的检测需要。

Determination of 30 Fatty Acids in Scallop by Ultrasonic Extraction Gas Chromatography

An analytical method for the simultaneous determination of 30 fatty acids(including saturated and unsaturated fatty acids) in scallop was developed.Samples were lyophilized,extracted under ultrasonic assistance,and methyl esterified with sulfuric acid and methanol before GC analysis.The fatty acids in scallop were quantified by internal standard method.The optimal conditions for fatty acid extraction from scallop samples,as determined using orthogonal array design,were a mixture of methanol and dichloromethane(1:3,V/V) as the extraction solvent at a material-to-liquid ratio of 1:140(mg/mL) and three replicate extractions for 15 min each time.Both extraction number and material-to-liquid ratio had a significant effect on fatty acid extraction(P< 0.05).A good linear relationship was found for all 30 fatty acids in the concentration range of 5.0-80.0 μg/mL with a correlation coefficient exceeding 0.999.The average recovery rates of 30 fatty acids at low and high spike levels were 1.3%-3.5% and 0.9%-3.1%,respectively(n = 5).The detection limits of the method varied in the range of 1.94-2.57 mg/kg(RSN = 3).This method was simple,rapid,sensitive and accurate and could meet the requirements for the determination of fatty acids in scallop and similar organisms.