Geographical Origin Traceability Of Rice Based On Element Analysis

Along with economic development and the continuous improvement of living standards,nowdays,when people buy food will take origin into consideration,different food origin will affect the price and quality.Driven by economic interests,shoddy or pastes false labels posing as famous and special products and other phenomena are offen apper on the market,which seriously damaged the interests of consumers and producers.This paper includes how to establish the method for the determination elements in rice and soil by ICP-MS,Study on the Characteristics of Elements Content and the Discrimination of the Origin of Rice in Different Producing Areas and the migration of elements in rice-soil system.Concert study content as follow:In order to establish a method for the determination of 27 elements in rice and soil by inductively coupled plasma mass spectrometry,Liaoning standard rice material and standard soil were used as samples,the mixed internal standard was used to correct matrix interference and signal drifting.The linear coefficient of above elements in rice and soil were 0.9986?1.0000 and 0.9913?0.9992,the RSD of above elements were below 5%,and the detection limit of the elements were in the range of 0.0023 ng/mL?52.15 ng/mL,the recoveries were in the range of 80.2%?108.6%'and 80.4%?111.0%,The recoveries of quantification limit were in the range of 81%?112.5%.The method was accurate?quick?simple,it was suitable for determining the elements in rice and soil.In order to research the characteristics of elements in rice from different areas were analyzed to explore the effect of three processing precisions of rice origin traceability,and to screen out the effective index in different processing precisions of rice origin discrimination.Total 66 kinds of rice samples from Hubei province,Jiangsu province,Liaoning province were regarded as the object of study,The contents of 26 chemical elements in different processing precisions(whole grain,brown rice,polished rice)of Be?B?Na?Mg?K?Ca?Ti?V?Cr?Mn?Fe?Co?Ni?Cu?Zn?Ga?As?Se?Rb?Sr?Mo?Cd?Sn?Sb?Ba?Pb were detected by ICP-MS.Then SPSS was used to analyze the data by analysis of variance(ANOVA),principal component analysis(PCA),cluster analysis(CA)and discriminant analysis(DA).The results showed that the element contents were different in the same processing precision from different provinces.In the whole grain samples,element contents of Mg?K?V?Cr?Co?Zn?Ga?Rb?Ba?Pb were significantly higher than other two areas in the samples from Hubei;element contents of Na?Fe?Cu?Se?Sr?Sn were significantly higher than other two areas in the samples from Liaoning;element contents of Fe?Se?Sr?Sn were significantly different with each other.In the brown rice samples,element contents of Be?Ga?Sb?Ba were significantly higher than other two areas in the samples from Hubei;element contents of Mg?Ca?Ti?Ni?Cu?As?Sr?Sn were significantly higher than other two areas in the samples from Liaoning;element contents of Ti?Ni?Ga?Sn were significantly different with each other.In the polished rice samples,element contents of Ga?Se?Sn were significantly higher than other two areas in the samples from Hubei;element contents of Ni and Ba were significantly higher than other two areas in the samples from Jiangsu;element contents of Mg?Ti?Cu were significantly higher than other two areas in the samples from Liaoning;element contents of Ti?Ni?Ga?Se were significantly different with each other.PCA and CA classified the samples of rice into different categories,which was consistent to the geographical origin,the principal component analysis is more intuitive to express the comprehensive information of the elements,and the analysis results are consistent with the analysis of the element contents.In the cluster analysis,the clustering effect of whole grain samples and polished rice samples is significantly better than brown rice samples,the cluster analysis accuracy of whole grain samples and polished rice samples is 98.5%,but the cluster analysis accuracy of brown rice samples is 93.9%.Furthermore,seven elements of Sn?Mg?B?Cr?Sr?Ca?Ga were screened by DA and suggested as better tracers for whole grain samples origin assessment,a percentage of 100%of correct classification was achieved by whole and cross-validated,seven elements of Ti?Ga?K?Cu?Mn?Sn?Ni were screened by DA and suggested as better tracers for brown rice samples origin assessment,a percentage of 100%of correct classification was achieved by whole and cross-validated.Similarly,seven elements of Ti?Ni?Ga?Sb?Cu?Na?Rb were screened by DA and suggested as better tracers for polished rice samples origin assessment,100%correct classification for all samples from three different regions,a percentage of 96.7%of correct classification was achieved by cross-validated.It is feasible to determine the geographical origin of rice based on element analysis.Under different processing precisions,different traceability index system should be used,and the origin traceability effect is different.In order to explore the migration and enrichment of elements of different processing in rice,the rice samples and soil samples from Hubei province,Jiangsu province,Liaoning province were regarded as the object of study,the enrichment coefficients were used to study the rice under different processing precisions enrich elements from soil,and the migration ability of different elements was compared and analyzed.The results showed the enrichment ability of different varieties of rice to the same element is different,when considering the elements enrichment rule in soil-rice system.For heavy metals,they are mainly concentrated in the hull and rice bran,with the improvement of processing accuracy,heavy metals can be effectively removed.Rice with different processing precision showed that highest enrichment coefficient of Cd element from soil,and the enrichment coefficient of Ba element was the lowest,which indicated that Cd element was active heavy metal,easily migrated in soil-rice system,while Ba element was inert metals than other heavy metals,it is not easy to migrate.The Cu element is relatively easy to enrich in bran layer.The whole grain,brown rice,polished rice samples from three different areas,Mo element showed that highest enrichment coefficient from soil,indicating that it is the most easily moving element in the soil-rice system,and the enrichment coefficient of rice on Mo elements were higher than whole grain and polished rice,which indicates that it is relatively easy to enrich in bran layer.While the Fe element has the lowest enrichment coefficient,indicating that it is the most difficult to migrate in the soil-rice system.The Sn and Ni are relatively easy to enrich in the endosperm,While the Cr element is relatively easy to enrich in the hull.