Tiwari Swapnil, Deb Manas Kanti, Sen Bhupendra K
School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, Chhattisgarh 492010, India.
School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, Chhattisgarh 492010, India.
Food Chem. 2017 Apr 15;221:47-53. doi: 10.1016/j.foodchem.2016.10.034. Epub 2016 Oct 11.
A new cloud point extraction (CPE) method for the determination of hexavalent chromium i.e. Cr(VI) in food samples is established with subsequent diffuse reflectance-Fourier transform infrared (DRS-FTIR) analysis. The method demonstrates enrichment of Cr(VI) after its complexation with 1,5-diphenylcarbazide. The reddish-violet complex formed showed λ at 540nm. Micellar phase separation at cloud point temperature of non-ionic surfactant, Triton X-100 occurred and complex was entrapped in surfactant and analyzed using DRS-FTIR. Under optimized conditions, the limit of detection (LOD) and quantification (LOQ) were 1.22 and 4.02μgmL, respectively. Excellent linearity with correlation coefficient value of 0.94 was found for the concentration range of 1-100μgmL. At 10μgmL the standard deviation for 7 replicate measurements was found to be 0.11μgmL. The method was successfully applied to commercially marketed food stuffs, and good recoveries (81-112%) were obtained by spiking the real samples.
建立了一种用于测定食品样品中六价铬（即Cr(VI)）的新型浊点萃取（CPE）方法，并随后进行漫反射傅里叶变换红外光谱（DRS-FTIR）分析。该方法证明了Cr(VI)与1,5-二苯卡巴肼络合后会发生富集。形成的红紫色络合物在540nm处有吸收峰。在非离子表面活性剂Triton X-100的浊点温度下发生胶束相分离，络合物被截留在表面活性剂中，并使用DRS-FTIR进行分析。在优化条件下，检测限（LOD）和定量限（LOQ）分别为1.22和4.02μg/mL。在1-100μg/mL的浓度范围内发现具有0.94的相关系数值的良好线性关系。在10μg/mL时，7次重复测量的标准偏差为0.11μg/mL。该方法成功应用于市售食品，通过对实际样品加标获得了良好的回收率（81-112%）。
