中红外区低浓度CO_(3)^(2-)水溶液摩尔吸光系数的测量

Measurement of Molar Absorptivity of Low-Concentration Carbonate Aqueous Solution in Mid-Infrared Region

本文通过测量30~100 mmol/L低浓度Na_(2)CO_(3)水溶液的红外吸收光谱,计算了CO32-的摩尔吸光系数。利用以硒化锌为基底的红外单次衰减全反射(ATR)附件测量30~100 mmol/L浓度Na_(2)CO_(3)水溶液的红外吸收光谱,将模拟的纯水的衰减全反射光谱作为基线,对Na_(2)CO_(3)水溶液的红外吸收光谱进行基线调整;利用Kramers-Kronig关系计算了Na_(2)CO_(3)溶液的折射率和消光系数,并进一步计算出Na_(2)CO_(3)溶液的有效光程及低浓度Na_(2)CO_(3)水溶液的摩尔吸光系数,计算得到的CO_(3)^(2-)的最大摩尔吸光系数为2421.99 L/(mol·cm)。

In this paper,the molar absorptivity of carbonate ions is calculated by measuring the infrared absorption spectra of 30-100 mmol/L low-concentration sodium carbonate aqueous solutions.The infrared absorption spectra of 30-100 mmol/L sodium carbonate aqueous solutions were measured using the infrared single attenuated total reflection(ATR)accessory based on zinc selenide.The simulated pure water ATR spectrum was used as the baseline to adjust the infrared absorption spectra of the sodium carbonate aqueous solutions.The Kramers-Kronig formula was used to calculate the refractive indices and extinction coefficients of the sodium carbonate solutions.Furthermore,the effective optical pathlengths and the molar absorptivities of the low-concentration sodium carbonate aqueous solutions were calculated.The calculated maximum molar absorptivity of carbonate ions is 2421.99 L/(mol·cm).