Investigation And Analysis Of Heavy Metal Pollutants And Illegal Additives In Rice Noodles In Nanchong City

Rice noodles as a kind of large-scale industrialized rice food,has a long history and is loved by consumers.rice noodles is characterized by large demand,large number of production enterprises,small scale,unstable product quality,poor production environment sanitation,and weak quality and safety management awareness,caused the heavy metal contaminants and the illegal additives in rice noodles has become a worrying food safety issue.This research carried on the thorough comprehensive research on rice noodles industry chain,collected 200 samples of different types and different sources of rice noodles.The microwave digestion-rapid removal acid sample pretreatment method、AFS analysis method for simultaneous determination of As and Hg and ICP-MS analysis method for simultaneous determination of Pb,Cd,Cr and Al is used to determine the content of Pb,Cd,Cr,As and Hg in rice noodles.National food safety standard methods and established ICP-MS analysis methods are used to detected the illegal additives such as rongalit（based on HCHO）,sulfite（based on SO₂）,borax（based on H₃BO₃）,and alum（based on Al）contents in rice noodles.Based on the results of heavy metal content detection in rice noodles,the distribution and the pollution status of heavy metals in rice noodles,and the health hazards of heavy metal intake are analyzed.Based on the detection results of four illegal additives in rice noodles,the content distribution of the four illegal additives is analyzed,the background value of the four illegal additives was discussed,and the safety of the four illegal additives in rice noodles was evaluated.The results were as follows:1.The microwave digestion-rapid removal acid sample pretreatmentmethod,AFS analysis methods and ICP-MS analysis method ensure that rice noodles samples can be quickly and completely dissolved,and avoid Hg volatilization loss at the same time,has the advantages of high recovery rate,good repeatability,low detection limit,wide linear range,fast speed and low cost,and were suitable for the determination of Pb,Cd,Cr,As,Hg and Al in rice noodles.2.The Pb,Cd,Cr,As,and Hg in average in 200 samples of rice noodles in Nanchong City wre 0.0374mg/kg,0.0362mg/kg,0.2341 mg/kg,0.0627 mg/kg,0.0092 mg/kg,Pb content over-standard rate was 1.00%,Cd content over-standard rate is 0.50%,Cr content over-standard rate was 2.0%.It shows that the Pb,Cd,Cr,As,Hg content was in the overall low range,and individual rice noodles samples exceeded the standard.Among rice noodles from different types,the order of over-standard rate was the dry rice noodles（5.12%）>semi-dry rice noodles（4.00%）>fresh rice noodles（0.00%）,Among rice noodles from different sources,the order of over-standard rate was the circulation link（7.16%）>the production link（3.13%）>the catering link（1.94%）,which indicates that the rice noodles were contaminated by certain heavy metals due to the accumulation of raw materials and pollution of production equipment.After entering the circulation link from the production link,the naked sales increased the heavy metal pollution in rice noodles.The rice noodles in the catering sector could reduce the heavy metals pollution in rice noodles to a certain extent after soaking.3.The comprehensive pollution index of heavy metals of 200 rice noodles samples in Nanchong was 0.380,which were safe,and the average order of the heavy metal single pollution index was Hg（0.462）>As（0.313）>Cr（0.234）>Pb（0.187）>Cd（0.181）,the contamination of Cr in 3 samples is mild,the contamination of Cr in 1sample is moderate,the contamination of Pb in 2 samples is mild,and thecontamination of Cd in 1 sample is mild.The comprehensive pollution index of heavy metals in dry rice noodles,semi-dry rice noodles,fresh wet rice noodles is 0.430,0.376,0.333,and the comprehensive pollution index of heavy metals in production,circulation and catering is 0.428,0.427,0.338.indicating that the overall condition of rice noodles in Nanchong City was not contaminated by heavy metals and was within a safe range,but individual rice noodles samples was contaminated4.The heavy metals intake comprehensive health hazard index of edible rice noodles for residents in Nanchong was 0.562,and the average order of the health hazard indexes of the five heavy metals was Cd（0.205）>Cr（0.133）>As（0.0981）>Hg（0.0761）>Pb（0.0502）,Cd was the most harmful to the health of people who eat rice noodles.The THQ of 4 different age groups was in the order of children（0.6987）>young adults（0.4999）>elderly（0.4526）>adolescents（0.4389）.Children were most likely to suffer health hazards from heavy metals contamination in rice noodles.Among the heavy metals intake comprehensive health hazard index of edible rice noodles of different genders,the THQ of heavy metals intake of male and female rice noodles were0.4953 and 0.4892,indicating that the overall situation of rice noodles in Nanchong would not cause health hazards to the consumers.children were more likely to suffer from health hazards of heavy metals than other groups,and men were more likely to suffer from health hazards of heavy metal than women.5.Among 200 samples of rice noodles in Nanchong,the content of sodium formaldehyde sulfoxylate（calculated as HCHO）,sulfite（calculated as SO₂）,borax（calculated as H₃BO₃）,and potassium aluminum sulfate（calculated as Al）ranged from n.d.～1.661mg./kg,n.d.～7.670 mg/kg,4.211～23.226 mg/kg,n.d.～29.545 mg/kg,and the detection rate of four illegal additives was H₃BO₃（100%）>Al（85.00%）>HCHO（63.00%）>SO₂（55.00%）,Setting the backgroud value of rongalit,sulfite,borax and alum in rice noodles as n.d.～10mg/kg,n.d.～10mg/kg,n.d.～45.30 mg/kg,n.d.～60.81 mg/kg,,the results showed that the detection rate of four illegal additives in rice flour was significantly different,the contents of 4 illegal additives were all within the range of the background value,and there was no illegal addition of rongalit,sulfite,borax and alum in rice noodles,so rice noodles were in a safe state.