Study Of Disinfectant Properties Of Ortho-phthalaldehyde

【Objective】 To compare the germicidal efficacy of ortho-phthalaldehyde and glutaraldehyde, and investigate the influential factors of the germicidal efficacy of ortho-phthalaldehyde, and evaluate the germicidal efficacy, metal corrosion and toxicity of compound ortho-phthalaldehyde.【Methods】Method of experimentThe available contents of ortho-phthalaldehyde and glutaraldehyde were examined by iodometric method and sulfuric acid titration method, respectively. Stability test of two kinds of disinfectants was conducted by method of accelerated aging. Neutralization test, influential elements test (concentration, pH), carrier quantitative germicidal test of two kinds of disinfectants against Bacillus subtilis var.niger, Staphylococcus aureus and Escherichia coli were conducted. In order to know the properties of compound ortho-phthalaldehyde, carrier quantitative germicidal tests, organic substance test, continual stability test, metal corrosion test and toxicology test (acute oral toxicity test of mice, micronucleus of mouse marrow polychromatic erythrocyte and acute skin irritation tests of rabbit) were conducted.Statistic method The bacterial count alive of experiment group and control group was transformed by log, and the log reduction was used to represent the germicidal efficacy. The repeated measure ANOVA was used to compare the germicidal efficacy among ortho-phthalaldehyde, glutaraldehyde and compound ortho-phthalaldehyde by SPSS 10.0 for Windows. The ANOVA and LSD were used to compare the rate of polychromatic erythrocyte between positive group and negative group when the rates were transposed by square.【Results】1 Study on germicidal properties of ortho-phthalaldehyde1.1 The stability of ortho-phthalaldehyde and glutaraldehyde After being stored in 54℃ incubator for 14 days, the available content of ortho-phthalaldehyde decreased by 0%, and the content of glutaraldehyde decreased by 7.8%. The available contents both decreased 10%, so the two kinds of disinfectants might be stored for 1 year in the room temperature.1.2 Comparison of germicidal efficacy of ortho-phthalaldehyde and glutaraldehyde Ortho-phthalaldehyde (2%w/v) and 2% glutaraldehyde both caused >6 log reduction against Bacillus subtilis var.niger in 4h, while 1% (w/v) ortho-phthalaldehyde gave 6.09 log reduction, and 1% glutaraldehyde gave 4.91 log reduction. 0.5% (w/v) ortho-phthalaldehyde and 2% glutaraldehyde gave 3.69 and 6.17 log reduction, respectively. Ortho-phthalaldehyde gave a 5.42, 4.68, 2.63 log reduction at the low concentration (0.1% w/v, 0.04% w/v, 0.02% w/v) against Staphylococcus aureus in 5 min, respectively. Glutaraldehyde at the same low concentration gave a 5.28, 0.86, 0.57 log reduction, respectively. Ortho-phthalaldehyde gave a 6.21, 4.99, 2.49 log reduction at the low concentration (0.1% w/v, 0.04% w/v, 0.02% w/v) against Escherichia coli in 5 min, respectively. Glutaraldehyde at the same low concentration gave a 6.31, 1.93, 0.68 log reduction. 1.3 The influential factors of the germicidal efficacy of ortho-phthalaldehyde Ortho-phthalaldehyde (0.5%w/v, 1%w/v, 2%w/v) gave a 3.69, 6.09, 6.35 log reduction against Bacillus subtilis var.niger in 4h, respectively. 0.5% w/v ortho-phthalaldehyde at pH 5.7, pH 7.0, pH 8.3,pH 9.0 gave a 0.41,0.95,2.56 and 0.71 log reduction against spores within 3 h, respectively.2 Study on disinfectant properties of compound ortho-phthalaldehyde2.1 Comparison of germicidal efficacy of ortho-phthalaldehyde, glutaraldehyde and compound ortho-phthalaldehyde Compound ortho-phthalaldehyde (0.5%w/v) caused a 5.77 log reduction against Bacillus subtilis var.niger, while 0.5%w/v ortho-phthalaldehyde and 2% w/v glutaraldehyde gave a 2.56,5.74 log reduction in 3h, respectively. Compound ortho-phthalaldehyde gave a 5.05, 3.71, 1.36 log reduction at the low concentration (0.1% w/v, 0.04% w/v, 0.02% w/v) against Staphylococcus aureus in 5 min, respectively. Ortho-phthalaldehyde at the same low concentration gave a 5.42, 4.68, 2.63 log reduction. Glutaraldehyde at...