固相萃取-固相光谱联用仪的构建及其应用于食品中罗丹明B的测定

设计并制造了以膜材料为分离富集介质的固相萃取装置和以漫反射光谱法为测定手段的测定装置相结合的自动化分析仪并应用于测定食品中罗丹明B的含量。该仪器由固相萃取装置、固相光谱测定装置和软件等3个部分组成。样品溶液(调节pH至2.00)负压自动进样,调节真空度在合适的速率下通过滤膜,待测物质富集于滤膜上。滤膜经热风干燥后由积分球在滤膜固相介质表面采集被测物质的漫反射光谱,仪器控制、光谱采集和数据处理直至报告的发出均由软件完成。在分析辣椒样品时,取样品0.500g,用水50.0mL超声提取10.0min,离心后取上清液测定罗丹明B的含量。测定时用混合纤维素膜进行富集,并选择测定波长为546.7nm。罗丹明B的线性范围为5.0~15.0μg·L^-1。分析红茶样品时,将样品用水稀释10倍后进行分析。在红茶的基质下,罗丹明B的线性范围为10.0~30.0μg·L^-1。上述2种样品的回收率为88.0%~108%,测定值的相对标准偏差(n=5)为4.6%~9.3%。

Assembly of Hyphenated Instrument of Solid Phase Extraction and Solid Phase Spectroscopy and Its Application to Determination of Rhodamine B in Food

An automatic analyzer was designed and fabricated by organic combination of solid phase extraction unit using filtering membrane as enrichment medium and diffuse reflection absorption spectrometry as detection unit,and the instrument was applied to the determination of rhodamine B in food.The analyzer consists of 3 parts:the solid phase extraction unit,the solid phase spectroscopy unit and the software.The sample solution(with its pH adjusted to 2.00)was introduced into the analyzer under reduced pressure and passed through the filtering membrane at an appropriate flow rate by adjusting the vacuum and the analytes were enriched on the membrane,which was then dried by hot air current.The information of diffuse reflection spectrometric data of the analytes was collected by the integrator from the solid phase of the dried membrane.The control conditions of the instrument,collection of spectral data,data treatment and finally the report of analytical results were completely controlled by the software.In the analysis of chilli,0.500 g of the sample was taken and extracted ultrasonically with 50.0 mL of water for 10.0 min,and after centrifuging,the supernatant was taken for determination of rhodamine B.Mixed cellulose membrane was selected for enrichment,and the wavelength at 546.7 nm was chosen for determination.Linearity range of rhodamine B was found in the range of 5.0-15.0μg·L-1.For analysis of red tea sample,the sample should be diluted 10 times with water.In the presence of the matrix of red tea,linearity range of rhodamine B was found in the range of 10.0-30.0μg·L-1.Test for recovery was made by standard addition method for both the samples,giving values of recovery in the range of 88.0%-108%.Values of RSDs(n=5)found were in the range of 4.6%-9.3%.