Determination Of Cr,As,Cd,Hg,Pb Content In Ya'an Vegetables By ICP-MS Method And Investigation And Evaluation Of Contamination Status

Vegetables are important in people's diet because of their rich vitamins and minerals,and their own characteristics will absorb heavy metals from the outside world,which will bring health risks.In this study,the contents of heavy metals in vegetables were the main objects,and the pretreatment method was optimized by orthogonal experiment,and the determination conditions of the instrument were optimized.The standard model and reaction mode of ICP-MS were established to determine the heavy metal Cr,As,Cd,Hg and Pb methods of vegetables.230 vegetable samples were collected from the production base,farmers'market and supermarkets in Ya'an city,and the contents of the heavy metal n the samples were determined by the above methods.The pollution of five kinds of heavy metals in ya'an vegetable was analyzed based on the method of supercalibration and pollution index.The safety of heavy metal in vegetables was evaluated by non-carcinogenic model and carcinogenic model.It turns out,With 7 mL of nitric acid,the microwave digestion power was set to 1000 W,and the digestion time was set to 25 min before the vegetable samples were processed and the digestion could achieve a good digestion effect.Cr,As and Cd used reaction mode,and the NH₃ flow rate was set to 0.6 ml/min,0.2 ml/min,0.6 ml/min,and the RPq value was set to0.6,0.6 and 0.5,Hg and Pb were determined by standard mode,and the interference elimination was the best.The method has low detection limit,high accuracy and sensitivity,which can meet the detection of five heavy metal elements in daily batch vegetable samples.The average content value of heavy metals in Ya'an vegetables was Cr>Pb>Cd>Hg>As,the exceeding rate was 2.6%,0,3.04%,0 and 0.87%,the heavy metal content of vegetables in Ya'an was low,and there were some cases exceeding the standard value.The overall vegetable pollution index of Ya'an was 0.16,less than 0.7,and the degree of pollution belonged to safety level.The comprehensive pollution Index of Houttuynia cordata,Brassica and garlic reached the pollution cordon,and the remaining vegetables were at a safe level.Leafy vegetables,brassica,bulbs,production base vegetable accumulation degree was deep,still in the safe range.The heavy metal Cr exposure was more obvious in Ya'an resident vegetables.The city residents through the consumption of Vegetables access to Cd was more harmful,As the second,Cr,Pb,Hg harm level was low,the harm index was 2.58E-05/a,lower than5.0E-05/a,within the scope of the security,not a threat to residents'health,but young children and women are more vulnerable to such harm.