Rapid Screening of Cadmium in Rice and Identification of Geographical Origins by Spectral Method.

Fang Li,Jihua Wang,Songxue Wang,Anxiang Lu,Jingwei Yin,Minghui Zhou,Li Xu

doi:10.3390/ijerph15020312

Abstract

The accuracy, repeatability and detection limits of the energy-dispersive X-ray fluorescence (XRF) spectrometer used in this study were tested to verify its suitability for rapid screening of cadmium in samples. Concentrations of cadmium in rice grain samples were tested by the XRF spectrometer. The results showed that the apparatus had good precision around the national limit value (0.2 mg/kg). Raman spectroscopy has been analyzed in the discrimination of rice grain samples from different geographical origins within China. Scanning time has been discussed in order to obtain better Raman features of rice samples. A total of 31 rice samples were analyzed. After spectral data pre-treatment, principal component analysis (PCA), K-means clustering (KMC), hierarchical clustering (HC) and support vector machine (SVM) were performed to discriminate origins of rice samples. The results showed that the geographical origins of rice could be classified using Raman spectroscopy combined with multivariate analysis.

Highlights

Rice (Oryza sativa L.) is the staple food for more than half the world’s population and serves as the major source of energy [1]
The accuracy, repeatability and detection limits of the energy dispersive X-ray fluorescence (XRF) spectrometer were verified, and the results indicated that the apparatus is able to meet the requirements of quick screening verified, and the results indicated that the apparatus is able to meet the requirements of quick of cadmium concentration in rice grain
Screening can reduce the risk of the problematic rice entering screening of cadmium concentration in rice grain

Summary

Introduction

Rice (Oryza sativa L.) is the staple food for more than half the world’s population and serves as the major source of energy [1]. Cadmium is a chronic potent nephrotoxin that is associated with many serious diseases. For non-smokers, large amounts of cereal grain intake is the main way for cadmium to enter the human body, especially for rice grain intake [2,3]. It is important to supervise the concentration of cadmium in rice before entering the market for sale or into the grain depot for storage. The traditional method of rice cadmium detection is inductively coupled plasma mass spectrometry (ICP-MS), but its tedious pretreatment, and its time-consuming and specialized operations make it unsuitable for use in grain depot or large wholesale market. A fast, on-site and non-destructive method for detecting the cadmium in rice grains is necessary. Some attempts have been made to use portable near-infrared (NIR) to analyze the trace metal concentration [4,5], but the accuracy was not high enough, because the trace metals have no direct information in the NIR spectrum, their contents need to be derived using other component peaks, which makes it hard to improve testing accuracy

Methods

Results

Conclusion