曲利本蓝共振瑞利散射法测定苹果中钙  

Determination of Calcium in Apples by Resonance Rayleigh Scattering Method with Trypan Blue

作　　者：张又丹 江虹[1] ZHANG Youdan, JIANG Hong(College of Chemistry and Chemical Engineering, Yangtze Normal University, Chongqing 408100, China)

机构地区：[1]长江师范学院化学化工学院,重庆408100

出　　处：《理化检验（化学分册）》2018年第11期1250-1254,共5页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：重庆市教委科技基金资助项目(KJ1401226);长江师范学院大学生创新训练项目(2016CXX201)

摘　　要：采用曲利本蓝共振瑞利散射法测定苹果中钙的含量。在pH 6.50的三羟甲基氨基甲烷-盐酸缓冲溶液中,曲利本蓝与钙(Ⅱ)及阳离子表面活性剂十六烷基三甲基溴化铵反应生成一种三元离子缔合物,使体系的共振瑞利散射(RRS)信号显著增强,最大共振瑞利散射峰位于波长348nm处。优化的试验条件如下:(1) pH 6.50的三羟甲基氨基甲烷-盐酸缓冲溶液的用量为2.00mL;(2)1.0×10^(-4) mol·L^(-1)曲利本蓝溶液的用量为2.50mL;(3) 4.00×102 mg·L^(-1)十六烷基三甲基溴化铵溶液的用量为0.40 mL;(4)反应时间为25 min。钙的质量浓度在0.007 0～0.080 0mg·L^(-1)内与体系的RRS增强程度(ΔIRRS)呈线性关系,检出限(3s/k)为0.001 3mg·L^(-1)。方法用于苹果样品的分析,加标回收率为98.3%～102%,测定值的相对标准偏差(n=6)为1.8%～2.3%。Resonance Rayleigh scattering method with trypan blue was applied to the determination of calcium in apples. In Tris-hydrochloric acid buffer solution of pH 6.50, trypan blue reacts with calcium （ Ⅱ ） and cationic surfactant hexadecyl trimethyl ammonium bromide （CTMAB） to form a ternary ion association complex, which led to a distinctly enhanced resonance Ravleigh scattering （RRS） signal of the svstem. The maximum resonance Rayleigh scattering peak was located at 348 nm. The optimized conditions found were as follows： ① amount of Tris-hydrochloric acid buffer solution of pH 6.50 was 2.00 mL; ② amount of 1.0 × 10^-4 mol · L^-1 trypan blue solution was 2.50 mL; ③ amount of 4.00× 10^2 mg · L^-1 CTMAB solution was 0.40 mL; ④ time of reaction was 25 min. Linear relationship between values of enhanced RRS intensity （△IRRS） and mass concentration of calcium was obtained in the range of 0.007 0-0.080 0 mg · L^- 1 , with detection limit （3s/k） of 0.001 3 mg · L^- 1. The proposed method was applied to the analysis of apple samples, giving values of recovery and RSDs （n = 6） in the ranges of 98.3%-102% and 1.8%-2.3% respectively.

关 键 词：共振瑞利散射法 曲利本蓝 钙 苹果 

分 类 号：O657.3[理学—分析化学]