Département de mathématiques, informatique et génie, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, Québec G5L 3A1, Canada.
Analyst. 2018 Sep 10;143(18):4387-4393. doi: 10.1039/c8an00687c.
Bicarbonate salts are used in various industrial processes and could even serve as an alternative source of carbon in bioprocesses involving photosynthetic organisms. Industrial productions require efficient monitoring and control to ensure that their output will meet target specifications. To this end, a simple and rapid in situ quantification method was developed for bicarbonate, carbonate and phosphate ions using Attenuated Total Reflectance-Fourier Transform Infrared (ATR FT-IR) spectroscopy combined with partial least squares (PLS). The resulting multivariate approach allows the simultaneous determination of inorganic carbon and orthophosphate ions concentrations in aqueous solutions (R2 > 0.98, root-mean-square-errors of the cross validation RMSECV < 3.3%). Validation of the method was achieved through replicability and repeatability tests. Univariate calibration graphs are linear over a concentration range of 150 mM (R2 > 0.9990). Quantification limits for those ions were in the 6.9-17.2 mM range, as determined from univariate models. The multivariate model was successfully applied to a microalgal culture of Scenedesmus obliquus using bicarbonate as the carbon source and a phosphate buffer to maintain the pH. This analytical technique did not require extraction or chemical treatment and no sample preparation is needed. The results demonstrate the potential of ATR FT-IR method to study inorganic carbon and phosphate species during a bioprocess.
碳酸氢盐在各种工业过程中都有应用，甚至可以作为涉及光合生物的生物过程中碳的替代来源。工业生产需要进行有效的监测和控制，以确保其产品符合目标规格。为此，本研究开发了一种简单快速的原位量化方法，用于利用衰减全反射傅里叶变换红外（ATR FT-IR）光谱结合偏最小二乘法（PLS）对碳酸氢盐、碳酸盐和磷酸盐离子进行定量分析。这种多元方法可以同时确定水溶液中无机碳和正磷酸盐离子的浓度（R2 > 0.98，交叉验证均方根误差 RMSECV < 3.3%）。该方法通过重复性和再现性测试进行了验证。单变量校准曲线在 150 mM 的浓度范围内呈线性（R2 > 0.9990）。从单变量模型中可以确定，这些离子的定量限在 6.9-17.2 mM 范围内。该多元模型成功应用于以碳酸氢盐为碳源、磷酸盐缓冲液维持 pH 值的斜生栅藻（Scenedesmus obliquus）的微藻培养中。该分析技术不需要提取或化学处理，也不需要样品制备。结果表明，ATR FT-IR 方法在生物过程中研究无机碳和磷酸盐物种具有潜力。
