摘要
建立快速、准确测定饮料及糕点中山梨酸的多波长紫外吸收光谱法。在p H 3.25 Tris-盐酸溶液中,碱性紫与山梨酸反应,在紫外区生成具有3个正吸收峰的二元离子缔合物。最大吸收峰位于254 nm,另两个吸收峰分别位于305 nm和223 nm,线性范围为0.03~1.4 mg/L,表观摩尔吸光系数(κ)分别为4.50×10^4L/(mol·cm)(254 nm)、2.09×10^4L/(mol·cm)(305 nm)和2.53×10^4L/(mol·cm)(223 nm),检出限为0.028 mg/L(254nm)、0.030 mg/L(305 nm)和0.025 mg/L(223 nm),当以单波长法(以254 nm为例)测定时,饮料的定量限为4.66 mg/L,糕点的定量限为1.68 mg/kg。当用双波长(254 nm+305 nm)或三波长法(254 nm+305 nm+223nm)测定时,表观摩尔吸光系数(κ)分别为6.59×10^4L/(mol·cm)和9.12×10^4L/(mol·cm),检出限分别为0.014 mg/L和0.0098 mg/L,饮料的定量限分别为2.33 mg/L和1.63 mg/L,糕点的定量限分别为0.843 mg/kg和0.590 mg/kg。以双波长法为例,样品的加标回收率和相对标准偏差RSD(n=5)分别为97.3%~102%和2.0%~2.7%。该法适于糕点及饮料中山梨酸的快速测定。
A rapid and accurate multi-wavelength ultraviolet absorption spectrometry for the determination of sorbic acid in drinks and pastries was established.In the pH 3.25 tris-hydrochloric acid solution,basic violet reacts with sorbic acid to form binary ion association complexes with three positive absorption peaks in the ultraviolet region.The maximum absorption peak was located at 254 nm,and the other two absorption peaks were located at 305 nm and 224 nm,respectively.Their linear range were0.03~1.4 mg/L;The apparent molar absorption coefficients(κ)were 4.50×10^4 L/(mol·cm)(254 nm),2.09×104 L/(mol·cm)(305 nm)and 2.53×10^4 L/(mol·cm)(223 nm),respectively;The detection limits were 0.028 mg/L(254 nm),0.030 mg/L(305 nm)and 0.025 mg/L(223 nm),respectively.When measured by single-wavelength method(254 nm as an example),the quantitative limit of drinks was 4.66 mg/L and the quantitative limit of pastries was 1.68 mg/kg.When measured by dual-wavelength(254 nm+305 nm)or three-wavelength(254 nm+305 nm+223 nm)method,the apparent molar absorptivity(κ)were 6.59×104 L/(mol·cm)and 9.12×10^4 L/(mol·cm),respectively;The detection limits were 0.014 mg/L and 0.0098 mg/L,respectively;The quantitative limit of beverage were 2.33 mg/L and 1.63 mg/L,respectively;The quantitative limit of pastries were 0.843 mg/kg and 0.590 mg/kg.When used dual-wavelength method as an example for measurement,the spiked recovery and relative standard deviation(RSD)(n=5)of samples were97.3%to 102%and 2.0%to 2.7%,respectively.This method was suitable for the rapid determination of sorbic acid in pastries and drinks.
作者
江虹
庞向东
向杰
JIANG Hong;PANG Xiangdong;XIANG Jie(College of Chemistry and Chemical Engineering,Yangtze Normal University,Chongqing 408100,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2020年第4期272-277,共6页
Food and Fermentation Industries
基金
重庆市教委科技基金资助项目(KJ1401226)
长江师范学院科技基金资助项目(2018CXX117)
关键词
山梨酸
饮料
糕点
碱性紫
多波长
紫外吸收光谱法
sorbic acid
drinks
pastries
basic violet
multi-wavelength
ultraviolet absorption spectrometry
