Simultaneous Analysis Of Cl^-、NO₂^-、NO₃^-and HPO4₂^-in Meat Product By Ion Chromatography

This research utilise the correlation theory of ion cromatographic method as theoretical basis. Based on the chromatographic analysis technics, analyzing the advantages of the use of ion cromatographic method to detect the chloridion, nitrate, nitrite and composite phosphate in meat products. In allusion to the questions in national standard, present the advice to make a use of ion cromatographic method to detect the chloridion, nitrate, nitrite, phosphate and composite phosphate in meat products. And work out the specific detection method and experiment conclusion. Because of the variety of foods and the matrix of samples, the pretreatment method is very different, so is the technical parameters of the instrument required. It can be a lot difficult to reach a satisfied result on the premise of uncertain meat product and various parameters index. This experiment use the meat product commercially available as the experiment material, making a research on the pretreatment of samples, the choice of segregation pattern and detection mode, the improvement of separation degree, also in retention time reducing and detection sensitivity improvement. It has certain creativeness and inventiveness, and the result of the experiment research indicate:(1)Using ion cromatographic to measure the chloridion in meat product. Adopting5mmol/L KOH as the leacheate. Extracting the samples with high purity water. Using solid phase column to cod removal. All can be done in10minutes. The results are as follows:Relative standard deviation is less than5%; Recovery rate is103.2%. Coefficient of association is0.9999within the linearity range of1.0-50.0. Indicating the high accuracy, good reproducibility, easy analysis, fast speed and stable results.(2)Using ion cromatographic to do the simultaneous determination of nitrite and nitrate in meat products. Improving the national standard method, adopting leacheate effect of6mmol/L KOH for30min.50mmol/L KOH for5min. The flow rate is1.2mL/min. Extracting the samples with high purity water, codding removal with C18solid phase extraction column, wiping out chloridion inference with column of Ag-Na. All can be done in20min. The results are as follows:selecting3samples of the same density, measuring continuously for6times. The relative standard deviation are less than5%and the recovery rate is between92.6～96.2%.(3)Using ion cromatographic to do the simultaneous determination of phosphate and composite phosphate in meat products. Adopting the leacheate effect of6mmol/L KOH for30min,50mmol/L KOH for5min. The flow rate is1.2mL/min. Extracting the samples with high purity water, codding removal with Ci8solid phase extraction column, wiping out chloridion inference with column of Ag-Na. All can be done in30min. The degree of precision and accuracy are good with this method. The linearly dependent coefficient is more than0.9999. The adding recovery rate is between88.1-108.5%which can satisfy the need of the detection. Compared with the method of national standard GB/T5009.87-2003, it is an environment friendly detection method with less pretheatment time and steps, also avoiding the use of highly toxic agents.