Determination Of The Content Of Sulfate In Food And Environment Samples By The Method Of FTIR

In this dissertation, the diffuse reflectance Fourier transform infrared spectroscopy(DRS-FTIR) technique was applied to determine the content of sulfate in food andenvironment samples with satisfactory results.This dissertation summarized the application status and the prospects of DRS-FTIRtechnique. The significance of determining sulfate in food and environment and some existingmethods were also introduced. In this experiment, three kinds of samples such as salt, soil andatmospheric particulate matter were determined. The experimental principles and theexperimental procedure were introduced in detail. Sodium chloride (NaCl) was used as thebackground and the resolution was8.0with30scans in the process of salt determination. Thevibrational infrared peak at1138cm-1was selected for determining sulfate in salt, and peakarea was used as the means of absorbance assessment. Three samples were determined, thecorrelation coefficient of standard curve were greater than0.9, the RSD was less than5%(n=6).There was no significant difference between this method and the weight method, therecoveries were between90%~110%. Potassium bromide (KBr) was used as the backgroundand the resolution was8.0with30scans in the process of sulfate and nitrate determination insoil. The vibrational infrared peak at600cm-1was selected for determining sulfate, and peakarea was used as the means of absorbance assessment. The vibrational infrared peak at1385cm-1was selected for the determination of nitrate, single wavenumber was used as themeans of absorbance assessment. The related coefficient was0.9976and0.9620, respectively.Five samples were determined, and the results were closed to ion chromatography (IC). KBrwas used as the background and the resolution was8.0with30scans in the process of sulfatedetermination in the atmospheric particulate matter. The vibrational infrared peak at600cm-1was selected for the determination of sulfate, and peak area was used as the means ofabsorbance assessment and the related coefficient was0.9629. Two samples were determined,and the results were closed to the method of IC.There was no pretreatment in the determination of sulfate in slat by DRS-FTIR exceptgrinding, furthermore, no regents consumption and waste liquid were produced during theexperiment. In the determination of environment samples, the procedure of extraction was needed. No waste liquid was produced during the experiment. Compared with standardmethod and classic method, diffuse reflectance FTIR was a simple, fast and low detection limitmethod. But the reproducibility and sensitivity was not as well as the standard method andclassic method.