Optimization Of Determination Of Lead In Meat By Atomic Absorption Spectrometry

Meat is an important part of our daily life,and the safety of meat products is very prominent,consumers are also very concerned about it.Heavy metal pollution is an important part of meat safety,testing agencies for meat products in the detection of heavy metals is more and more stringent,but for the atomic absorption of meat products in the detection of heavy metal content,the heating procedures used therein and the added matrix modifiers are not specified.In most cases,experience-based tended to deviations is resulted in unnecessary losses.In this paper,the contents of Pb in the samples of Sauce stewed meat were detected by dry ashing,wet digestion and microwave digestion three kinds of pretreatment methods and five kinds of matrix modifiers involving Mg(NO3)2 with NH4H2PO4,NH4H2PO4,Pd(NO3)2,Pd(NO3)2 with Mg(NO3)2 and Pd(NO3)2 with NH4H2PO4.In order to study the key process technologies such as the ashing temperature,the atomization temperature and the amount of matrix modifier in the process of detecting the content of Pb in the meat sample,we view sample spiked recovery rate as an indicator and use the response surface experiment to optimize the technical parameters,leading to provide theoretical guidance for improving the accuracy of detection.Specific research results are as follows:First,the matrix modifier detection conditions Optimized results:1.Mg(NO3)2 with NH4H2PO4 detection conditions: ashing temperature: 750℃,atomization temperature: 1680℃,the amount of matrix modifier added: 3 μL.2.NH4H2PO4 detection conditions: ashing temperature: 680 ℃,atomization temperature: 1440℃,the amount of matrix modifier added: 3 μL.3.Pd(NO3)2 detection conditions: ashing temperature: 820 ℃,atomization temperature: 1670℃,the amount of matrix modifier added: 4 μL.4.Pd(NO3)2 with Mg(NO3)2 detection conditions: ashing temperature: 860 ℃,atomization temperature: 1890℃,the amount of matrix modifier added: 3 μL.5.Pd(NO3)2 with NH4H2PO4 detection conditions: ashing temperature: 830 ℃,atomization temperature: 1680℃,the amount of matrix modifier added: 3 μL.Determination of standard material for chicken composition analysis underoptimum conditions,the deviation of Mg(NO3)2 with NH4H2PO4,NH4H2PO4,Pd(NO3)2,Pd(NO3)2 with Mg(NO3)2 and Pd(NO3)2 with NH4H2PO4 was 0.0321 μg / L,0.0054 μg / L,0.0401 μg / L,0.9215 μg / L,0.0151 μg / L respectively.Second,the sample spike recovery:1.dry ashing: sample spiked recovery rate reached 76.17%-84.67%.2.wet digestion: sample spiked recovery rate reached 86.88%-97.55%.3.microwave digestion: sample spiked recovery rate reached 89.53%-97.87%.The recovery rate was measured by adding Pb standard material to the sample to compare the three different pretreatment methods.We concluded that the highest recovery rate is microwave digestion,indicating that using the previous treatment methods,the test results are high accuracy and stability.