固相微萃取法萃取液态奶味香精挥发性香成分条件的优化

Optimization of Analytical Method for Volatile Components from Liquid Diary Flavor Using Solid-phase Microextraction

采用固相微萃取法,对液态奶味香精中的挥发性香成分进行了萃取条件的优化研究,得到了较佳的萃取条件。以23种奶味香料化合物组成的模拟奶味香精体系为研究对象,对预热温度（30-80℃）,萃取时间（10-180 min）,样品量（1-11 mL）和SPME纤维种类（65μm CWAX/DVB,65μm PDMS/DVB,75μm CAR/PDMS和50/30μm DVB/CAR/PDMS）4个因素进行了考察。发现这4个因素对香精中挥发性香成分萃取的选择性和对检出限的灵敏性均有显著性影响。结果表明,PDMS/DVB纤维对奶味香精中挥发性化合物的选择性最好,灵敏度最高,其次是DVB/CAR/PDMS。通过单因素实验,得到优化的固相微萃取条件是：预热温度50℃,萃取时间40 min,样品量5 mL。将得到的优化参数集中用于市售奶味香精样品分析,与对照组的固相微萃取结果相比,挥发性香成分的种类增加了30种,总峰面积增加了20倍,验证了固相微萃取参数优化的实用性。

An analytical method for volatile compounds of diary flavor by solid-phase microextraction was established and optimized by using a mimic diary flavor containing 23 kinds of diary-flavor compounds as the research object. The four factors such as the incubation temperature（30 -80℃） and time （ 10 - 180 min）, sample volume （ 1 - 11 mL）, and the type of SPME fiber（65 μm C WAX/DVB ,65μm PDMS/DVB,75 μm CAR/PDMS and 50/30 μm DVB/CAR/PDMS） were investigated. All these factors-markedly effected remarkably the sensitivity and selectivity for flavor analyses. Among the four fibers tested, the PDMS/DVB fiber had the greater sensitivity to a more diverse range of volatile components,followed by DVB/CAR/PDMS. SPME optimal conducted conditions were established by using a single factor test, as follows ： incubation temperature of 50℃, incubation time of 40 min, and sample volume of 5 mL. Based on the results obtained, the optimized method was selected for the analysis of a commercial dairy flavor. In contrast to the untried method, the quantities of volatile components increased to 30 kinds, the total peak areas enhanced to 20 fold. The optimization of solid-phase microextraction showed a significant practicability.