取样品约0.5 g,加入饱和氯化钠溶液0.5 mL,涡旋1 min。加入正己烷3 mL,超声提取3 min,离心30 s。取上清液2 mL,加入0.1 mol·L^-1盐酸溶液0.5 mL,振荡30 s,离心15 s,取下层提取液作待测液。取纳米金溶胶150 μL,加入待测液50 μL以及1 mol·L^-1氯化钠溶液50 μL,振荡10 s后供便携式拉曼光谱仪分析。结果显示,利多卡因和辛可卡因的表面增强拉曼特征峰组分别为505,670,1 081,1 254 cm^-1和509,774,1 379,1 599 cm^-1,可有效区分这两种药物和其他同类型局部麻醉药。利多卡因和辛可卡因的仪器检出限和方法检出限分别为0.10 mg·L^-1和5 mg·kg^-1。方法适用于固体乳膏、润肤水以及凝胶状精华等常见化妆品基质中利多卡因和辛可卡因2种局部麻醉药的快速筛查。

The sample of 0.5 g was taken, and saturated sodium chloride solution of 0.5 mL was added. After swirling for 1 min, n-hexane of 3 mL was added, and the mixture obtained was extracted for 3 min by ultrasound, and centrifuged for 30 s. The supernatant of 2 mL was taken, and 0.1 mol·L^-1 hydrochloric acid solution of 0.5 mL was added. After swirling for 30 s and centrifuging for 15 s, the lower layer of extract was collected. Colloridal gold nanoparticles of 150 μL was taken, and the lower layer extract of 50 μL and 1 mol·L^-1 sodium chloride solution of 50 μL were added. The mixed solution was swirled for 10 s, and detected by portable Raman spectrometer. As shown by the results, the surfance-enhanced Raman characteristic peaks of lidocaine and cinchocaine were 505, 670, 1 081, 1 254 cm^-1 and 509, 774, 1 379, 1 599 cm^-1, and lidocaine and cinchocaine could be effectively distinguished from other local anesthetics by the above Raman characteristic peaks. Instrument detection limits of lidocaine and cinchocaine were 0.10 mg·L^-1, and method detection limits were 5 mg·kg^-1. The proposed method was suitable for rapid screening of the 2 local anesthtics (lidocaine and cinchocaine) in common cosmetic substrates, such as solid cream, lotion and gel essence.