中红外吸收光谱的气相过氧化氢浓度测量

气相过氧化氢为强氧化剂，其消毒、灭菌的最终产物为水和氧气，具有无残留、安全、快速消毒以及广泛的材料兼容性等优点。广泛应用于制药、医疗、卫生、生物安全等领域，特别是新冠肺炎、MERS、SARS以及甲流等呼吸类传染性疾病的消毒防治。为保证灭菌效果，防止无菌检查的假阴性或者假阳性，需要对过氧化氢的浓度进行监测。基于1 255 cm-1量子级联激光器可调谐激光吸收光谱技术研制了一套气相过氧化氢浓度测量装置，浓度测量范围为0~1 800 ppm。采用V型光路结构、窗口片将检测仪主要部件与过氧化氢进行隔离，避免过氧化氢腐蚀。针对高浓度、高吸光度时一阶泰勒级数近似透射率函数误差较大这一情况，采用二阶泰勒级数近似透射率函数，导出了二次谐波信号关于气体浓度的二次函数。二次谐波信号测得是电压值，采用高锰酸钾滴定法对其进行标定、溯源。最终得到气相过氧化氢浓度的测量公式，对高低浓度过氧化氢都拟合较好，拟合误差最大为3%。当湿度变化时，二次谐波信号没有发生变化，排除水分对过氧化氢测量的影响，适用于灭菌过程中常压下高浓度VHP的浓度测量。

Measurement of Vapor Hydrogen Peroxide Based on Mid Infrared Absorption Spectroscopy

Vapor hydrogen peroxide is a strong oxidant.The final product is water and oxygen.It has the advantages of no residue,safety,rapid disinfection and wide material compatibility.Vapor hydrogen peroxide sterilization is widely used in pharmaceutical,medical,health,and biosafety fields to ensure the safety of drugs,medical devices and food,especially used for disinfection and prevention of respiratory infectious diseases such as COVID-19,MERS,SARS and H1N1.In order to ensure the sterilization effect,hydrogen peroxide detector is used to monitor the concentration of hydrogen peroxide.Based on the tunable laser absorption spectroscopy technology of 1255 cm^-1quantum cascade laser,a vapor hydrogen peroxide concentration measuring device is developed.The concentration range is 0~1800 ppm.The main parts of the detector are isolated from hydrogen peroxide by V-type optical path structure and optical window to avoid hydrogen peroxide corrosion.In view of the fact that the error of transmittance function approximated by the first-order Taylor series is large in the case of high concentration and high absorbance,the second-order Taylor series is used to approximate transmittance function,and the second-order function of the second harmonic signal with respect to the gas concentration is derived.The second harmonic signal is the voltage value,which is calibrated and traced by potassium permanganate titration.Finally,the measurement formula is obtained,which fits the high and low concentration hydrogen peroxide well,and the maximum fitting error is 3%.When the humidity changes,the second harmonic signal does not change,excluding the influence of moisture on the measurement of hydrogen peroxide,which is suitable for the measurement of high concentration VHP at atmospheric pressure during the sterilization process.