The Establishment And Application Of Methods For Simultaneous Determination Of Several Functional Components In Compound Chemical Disinfectants By High Performance Capillary Electrophoresis

This paper is mainly focus on new method development for the simultaneous determination of multiple effective components such as chlorhexidine acetate and BAC; o-phthalaldehyde （OPA）, p-chloro-m-xylenol （PCMX） and triclosan, chlorhexidine acetate and polyhexamethylene biguanide （PHMB） in compound chemical disinfectants by high performance capillary electrophoresis （HPCE）. The established three new methods were used to analyze compound chemical disinfectants and detergents collected from the local markets. The results were compared with those assayed by high performance liquid chromatography （HPLC） mehtod. The thesis consists of the following three parts:The first part is new method development for the simultaneous determination of chlorhexidine acetate and BAC (C₁₂-BAC, C₁₄-BAC, C₁₆-BAC) in compound chemical disinfectants by capillary zone electrophoresis （CZE）. The factors such as the buffer concentration and pH, the content of acetonitrile and sample solution, which influence the separation and accurate assay of real samples, were investigated in detail. The analysis was carried out using an uncoated capillary with 50μm i.d and 37 cm total length. The running buffer was V （150 mmol/L NaH2PO4 + 62.5 mmol/L H3PO4 （pH 2.5））∶V （acetonitrile） = 3∶2. The sample solution was V （50 mmol/L HAc）∶V （acetonitrile） =1∶1. The detection wavelength was 214 nm. The relative standard deviations （RSD） of corrected peak area precisions of the four components were in the range of 1.2%².2%. The RSDs of migration time were less than 0.7%. The limits of detection （LOD, S/N=3） for chlorhexidine acetate, C₁₂-BAC, C₁₄-BAC and C₁₆-BAC were 0.3, 0.5, 0.5 and 0.5 mg/L, respectively. The limits of quantitation （LOQ, S/N=10） were 1.0, 1.5, 1.5, and 1.5 mg/L, respectively. The corrected peak area and the concentration of the four components mentioned above showed a good linear relationship within the range of 2⁴00 mg/L, 1²00 mg/L, 1²00 mg/L and 1²00 mg/L, with linear correlation coefficients （r） of 0.9995, 0.9998, 0.9997 and 0.9998, respectively. The established method was used for the determination of real samples. The results were in good agreement with those of HPLC method.The second part introduced a novel method for the separation and determination of OPA, PCMX and triclosan in compound chemical disinfectants in one run by micellar electrokinetic chromatography （MEKC）. The factors such as the buffer concentration and pH, the concentration of SDS, additive types and concentration, and the sample solution, et al., which influence the separation of the three compoents were investigated in detail. The analysis was carried out using an uncoated capillary with 50μm i.d and 30 cm total length. The running buffer was 20 mmol/L Na₂B₄O₇ and 80 mmol/L sodium dodecyl benzene sulfonate （SDS）. The sample solution was V （2 mmol/L Na₂B₄O₇ +8 mmol/L SDS）∶V （methanol） = 9∶1. The detection wavelength was 214 nm. The RSDs of corrected peak area of the three components were in the range of 1.1%³.8 %, the RSDs of migration time were less than 0.9%. The LODs （S/N=3） for OPA, PCMX and triclosan were 4, 0.4 and 0.4 mg/L, respectively. The LOQs （S/N=10） were 12, 1.2, and 1.2 mg/L, respectively. The corrected peak area and the concentration of the three components mentioned above showed good linear relationship within the range of 12² 000 mg/L, 1.2²00 mg/L and 1.2²00 mg/L with linear correlation coefficients of 0.9994, 0.9993 and 0.9995, respectively. The novel method was used for the determination of compound chemical disinfectants and detergents collected from the local markets. The results were in good agreement with those of HPLC method.Finaly, A new MEKC method for the simultaneous determination of PHMB and chlorhexidine acetate in compound chemical disinfectants has been established. The factors such as the buffer concentration and the pH, the content of acetonitrile , additives and sample solution, which influence the separation of the two components, were investigated in detail. The analysis was carried out using an uncoated capillary with 50μm i.d and 47 cm total length. The running buffer was 30 mmol/L NH₄Ac +22.5 mmol/L NH3 + 50 mmol/L SDS +5 mmol/L sodium cholate （SC） +0.8 g/L PEG 20 000. The sample solution is a 1∶10 dilution of the running buffer with ultrapure water. The detection wavelength was 214 nm. The RSDs of corrected peak area of PHMB and chlorhexidine acetate at low, medium and high concentration levels were in the range from 0.7% to 2.3%. The RSDs of migration time were all less than 1.1%. The LODs （S/N=3） for PHMB and chlorhexidine acetate were 2.0 and 1.0 mg/L, respectively. The LOQs （S/N=10） were 6.0 and 3.0 mg/L, respectively. Good linear relationships were established between the corrected peak area and the concentration of the two components mentioned above in the range from 6 to 200 mg/L and 3 to 200 mg/L, with a correlation coefficients of 0.9992 and 0.9988, respectively. The method was used to determine PHMB and chlorhexidine acetate in the disinfectant samples and satisfactory results were obtained.