Studies On The Analysis Of Microcystin And Three Toxic Organic Pollutants By Linear Sweep Polarography And Alkaline Phosphatase Inhibition Assay

Microcystin-RR , Benzidine , Pentachlorophenol and 2,4-Dinitrophenol were selected to study their determination by linear sweep polarography. The inhibition of calf intestinal alkaline phosphatase by them and the mechanisms were also studied. Finally, their determination by alkaline phosphatase inhibition assay were established. In this paper, the research substances are as follows:(1) The determination of Microcystin-RR by linear sweep polarography was studied. Microcystin-RR generated sensitive adsorption wave at the point of-1.55v in the presence of Ni²⁺-Borax media. The peak point current (I"_p) was better linear with the concentration of Microcystin-RR over the range of 1.50⁸.00 mg/L. The determination limit was 0.07 mg/L. This method was applied to the determination of Microcystin-RR in water samples and the results were satisfactory. Spectrophotometry was used to study the changes of the activity of calf intestinal alkaline phosphatase (CIAP) in the presence of Microcystin-RR with different concentrations. The relative activity of CIAP was calculated according to the absorbance variation. The results showed that Microcystin-RR could inhibit the activity of CIAP. And the inhibition mechanism was studied profoundly. The inhibition type of Microcystin-RR on CIAP was determined by using the double reciprocal plot. The results showed that Microcystin-RR was a uncompetitive inhibitor of CIAP. The ratio of the activity of CIAP being inhibited by MC-RR was better linear with the concentration of Microcystin-RR over the range of 0.1⁷mg/L. The determination limit was 0.05mg/L.(2) The determination of pentachlorophenol (PCP) by linear sweep polarography was studied. PCP generated sensitive adsorption wave at the point of -0.52v in the presence of Ethanol-Borax media. The peak point current (I"_p) was better linear with the concentration of PCP over the range of 1.50×10^-33.00× 10^-5 mol/L. The determination limit was 1.00 × 10^-6 mol/L. This method was applied to the determination of PCP in water samples and the results were satisfactory. Spectrophotometry was used to study the changes of the activity of CIAP in the presence of PCP with different concentrations. The relative activity of CIAP was calculated according to the absorbance variation. The results showed that PCP could inhibit the activity of CIAP. And the inhibition mechanism was studied profoundly. The inhibition type of PCP on calf intestinal alkaline phosphatase was determined by using the double reciprocal plot. The results showed that PCP was a noncompetitive inhibitor of CIAP. The ratio of the activity of CIAP being inhibited by PCP was better linear with the concentration of PCP over the range of 2.5 × 10^-4 3.0 × 10^-3 mol/L. The determination limit was 8.0 × 10^-4 mol/L.(3) The determination of 2,4-Dinitrophenol (2,4-DNP) by linear sweep polarography was studied. 2,4-DNP generated sensitive adsorption wave at the point of -0.41v in the presence of glycol-ammonium chloride media. The peak point current (I"p) was better linear with the concentration of 2,4-DNP over the range of 1.00 X lO^—S.OOXlO^mol/L . The determination limit was 8.00X10'8mol/L. This method was applied to the determination of 2,4-DNP in water samples and the results were satisfactory. Spectrophotometry was used to study the changes of the activity of CIAP in the presence of 2,4-DNP with different concentrations. The relative activity of CIAP was calculated according to the absorbance variation. The results showed that 2,4-DNP could inhibit the activity of calf intestinal alkaline phosphatase. And the inhibition mechanism was studied profoundly. The inhibition type of 2,4-DNP on CIAP was determined by using the double reciprocal plot. The results showed that 2,4-DNP v/as a uncompetitive inhibitor of CIAP. The ratio of the activity of CIAP being inhibited by 2,4-DNP was better linear with the concentration of 2,4-DNP over the range of 0.2—1.5mg/L. The determination limit was 0.07mg/L.(4)The determination of Benzidine by linear sweep polarography was studied. Benzidine generated sensitive adsorption wave at the point of -0.66v in the presence of HC1-Formaldehyde media. The peak point current (I"p) was better linear with the concentration of Benzidine over the range of 3.00X10"7¹.00X10"5mol/L. The determination limit was 8.00 X 10"8mol/L. This metod was applied to the determination of Benzidine in water samples and the results were satisfactory. Spectrophotometry was used to study the changes of the activity of CIAP in the presence of Benzidine with different concentrations. The relative activity of CIAP was calculated according to the absorbance variation. The results showed that Benzidine could inhibit the activity of CIAP. And the inhibition mechanism of the inhibition was studied profoundly. The inhibition type of Benzidine on CIAP was determined by using the double reciprocal plot. The results showed that Benzidine was a competitive inhibitor of calf intestinal alkaline phosphatase. The ratio of the activity of CIAP being inhibited by Benzidine was better linear with the concentration of Benzidine over the range of 5.0X108⁷.0X10"7mol/L . The determination limit was 1.0 X 10"8mol/L.