采用酯化衍生-气相色谱/质谱法分析了5种市售植物油中的10种脂肪酸,脂肪酸总量在葵花籽油和玉米油中最高,在花生油和菜籽油中最低,橄榄油居中。组成分布特征以油酸和亚油酸占绝对优势（84.8%~94.7%）,但橄榄油中油酸和亚油酸的比值为1.0,显著高于其他油脂。500 W汞灯作光源,模拟光照24 h后,脂肪酸整体都呈现下降趋势,其中葵花籽油的下降幅度最大（50%）,而玉米油的下降幅度最小（30%）;随光照时间延长,油酸与亚油酸的比值呈逐渐升高的趋势,但反油酸与油酸的比值虽有所降低,但不同油脂之间差异较大。总体而言,光照可以降低植物油的营养价值成分,在贮藏和使用过程中,应尽量避光保存。A total of 10 fatty acids in 5 kinds of vegetable oil bought from local supermarket were analyzed using esterification-GC/MS.The highest concentrations of fatty acids were found in sunflower seed oil and maize oil,followed by olive oil,peanut oil and colza oil.The composition of fatty acids in vegetable oil was characterized by very high oleic acid and linoleic acid,accounting for 84.8%-94.7% of the total fatty acids.The ratio of oleic acid to linoleic acid was 1.0,which was much higher than those in other oils.A 500 W mercury lamp was used to produce UV light source and the irradiation period was set as 0,8,16 and 24 h,respectively.The highest loss of fatty acids was found in sunflower seed oil（around 50%） while the lowest loss was found in maize oil（around 30%）.The ratio of oleic acid to linoleic acid increased with irradiation time,while the ratio of trans oleic acid to oleic acid showed slight decrease trends and varied from oil to oil.In general,the vegetable oil needed to keep in dark place during the storage and in use in order guarantee the quality
