双通道在线连续流动分析法同时测定环境水样中总磷和磷酸盐

准确测定环境水样中的总磷和磷酸盐含量,对于评价水体的环境污染程度和富营养化程度具有非常重要的意义。本文在对比已有国标分析方法的基础上,建立了连续流动分析法同时测定环境水样中总磷和磷酸盐的分析方法。样品和总磷、磷酸盐的试剂分别通过自动进样器和蠕动泵在线载入各自管路,再进入各自的化学分析模块进行化学反应,之后进入各自的比色计在波长为660nm条件下完成检测,全程在线自动分析,因此,可以实现一次进样就可以同时测定样品中总磷和磷酸盐含量,大大提高了分析效率。对消解试剂及浓度、加热温度、泵速等条件进行了最佳优化,保证了样品能消解完全且反应充分。将采集后的样品酸化处理后在10天内进行分析测定,避免了时间过长后水样变质对结果的影响。以空白介质溶液配制校准系列,使得校准系列与试样基体匹配,消除了基体效应干扰影响。结果表明：在最佳的实验条件下,校准曲线的线性相关性较好；总磷和磷酸盐测定结果的相对标准偏差(RSD)为1.05%～2.64%,精密度较好；总磷和磷酸盐方法检出限分别为0.010mg/L和0.022mg/L；经国家水样标准物质验证,方法相对误差(RE)均在±5%以内,测定值与标准值相吻合,方法准确度较好；应用本文方法对实际样品进行分析,并与传统国标方法进行比对,测定值的相对偏差(RD)均小于5%,更进一步验证了该分析方法准确可靠,能够满足大批量环境水样中总磷和磷酸盐的分析要求。

Simultaneous Determination of Total Phosphorus and Phosphate in Environmental Water Samples by Dual Channel Online Continuous Flow Analysis

Accurate determination of total phosphorus and phosphate content in environmental water samples was of great significance for evaluating the degree of environmental pollution and Eutrophication of water bodies. On the basis of comparing existing national standard analysis methods, this article established a continuous flow analysis method for the simultaneous determination of total phosphorus and phosphate in environmental water samples. Samples and reagents of total phosphorus and phosphate were loaded into their respective pipelines online through the automatic sampler and Peristaltic pump respectively, and then enter their respective chemical analysis modules for chemical reaction, and then enter their respective colorimeters to complete the detection under the condition of 660nm wavelength. The whole process of online automatic analysis can be realized. Therefore, the content of total phosphorus and phosphate in samples can be determined simultaneously with one sample injection, greatly improving the analysis efficiency. The optimal optimization of digestion reagents and concentration, heating temperature, pump speed and other conditions had been carried out to ensure that the sample can be completely digested and the reaction was sufficient. After acidification treatment, the collected samples were analyzed and determined within 10 days to avoid the impact of water sample deterioration on the results after a long time. The calibration series was prepared with blank medium solution to match the calibration series with the sample matrix, eliminating matrix effect interference. The results showed that under the optimal experimental conditions, the linear correlation of the calibration curve was good. The relative standard deviation (RSD) of the total phosphorus and phosphate determination results was 1.05%~2.64%, indicating good precision. The detection limits for total phosphorus and phosphate methods were 0.010mg/L and 0.022mg/L, respectively. After verification by the national water sample standard substance, the relative error (RE) of the method was within ± 5%, and the measured values were consistent with the standard values, indicating good accuracy of the method. The method described in this article was applied to analyze actual samples and compared with traditional national standard methods. The relative deviation (RD) of the measured values was less than 5%, further verifying the accuracy and reliability of this analysis method, which can meet the analysis requirements of total phosphorus and phosphate in large batches of environmental water samples.