A method that combines five-way fluorescence kinetics with fourth-order calibration for interference-free quantification of diclofenac sodium in river water was proposed and tested. Traditional fluorescence methods may not be suitable for such measurements since the fluorescence properties of the analyte are highly dependent on both pH and irradiation time in situ. In the method considered here, a five-way emission-excitation-time-pH data array was obtained from the samples by introducing the pH level and irradiation time as two extra modes. Then the data array was resolved by three fourth-order calibration algorithms: alternating fitting weighted residue quinquelinear decomposition (AFWRQQLD), five-way parallel factor analysis (five-PARAFAC), and alternating quinquelinear decomposition (AQQLD). The average recoveries and detection limits calculated for diclofenac sodium in a set of analyte-spiked river water samples using AFWRQQLD, five-PARAFAC, and AQQLD were 97.2 ± 3.2% and 1.9 ng mL⁻¹, 96.8 ± 3.0% and 4.0 ng mL⁻¹, and 92.6 ± 2.7% and 2.5 ng mL⁻¹, respectively. A study of other figures of merit, statistical analysis, an elliptical joint confidence region test, and a t-test were additionally carried out to validate the analytical performance of the proposed method in detail. The results demonstrated that this new method required only two steps (fluorescence measurement and algorithm analysis) to determine the analyte concentration. It could therefore provide the basis for developing novel reliable and sensitive approaches for the accurate detection of pharmaceutical pollutants with unstable fluorescence properties in real complex matrices such as environmental water samples.

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提出并测试了一种将五效荧光动力学与四阶校正相结合的方法，用于无干扰定量测定河水中的双氯芬酸钠。传统的荧光方法可能不适用于此类测量，因为分析物的荧光特性高度依赖于pH值和原位照射时间。在此处考虑的方法中，通过将pH值和照射时间作为两种附加模式引入，从样品中获得了五向发射激发时间-pH数据阵列。然后，通过三种四阶校准算法解析数据数组：交替拟合加权残差五线性分解（AFWRQQLD），五向并行因子分析（five-PARAFAC）和交替五线性分解（AQQLD）。^-1，96.8±3.0％和4.0纳克毫升^-1，和92.6±2.7％和2.5纳克毫升^-1分别。另外还进行了其他性能指标的研究，统计分析，椭圆联合置信区域检验和t检验，以详细验证所提出方法的分析性能。结果表明，该新方法仅需两个步骤（荧光测量和算法分析）即可确定分析物的浓度。因此，它可以为开发新的可靠和灵敏的方法提供基础，以准确检测在实际复杂基质（例如环境水样品）中具有不稳定荧光特性的药物污染物。

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