The usefulness of dissolved organic nitrogen (DON) data to environmental science depends on the precision of each calculated concentration. The precision of a calculated DON concentration is based on propagation of error from the measured nitrogen fractions used to calculate the DON concentration. We present an improved approach for calculating DON precision that strengthens conventional error propagation by developing empirical relationships between precision and concentration for each of the measured nitrogen fractions used to calculate DON concentration. Because the concentration and relative importance of each measured nitrogen fraction differ among samples, DON precision and the corresponding detection limit are likely to be different for each sample. Case studies from two different research efforts, a synoptic study of surface water DON and an experimental assessment of DON leached from heat-treated soils, demonstrate how the proposed approach can be tailored to the analytical methods and concentration ranges expected for any research project. In addition, current recommendations for pretreatment (e.g., dialysis) to improve DON precision should be modified to include consideration of analytical precision. Improved characterization of DON precision facilitates a more realistic assessment of sample-specific detection limits, and the results can be generalized to support decisions about pretreatment and statistical analysis of DON data.

中文翻译：

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溶解有机氮计算精度的表征极限

溶解有机氮（DON）数据对环境科学的有用性取决于每个计算出的浓度的精度。所计算出的DON浓度的精度基于用于计算DON浓度的测得氮分数的误差传播。我们提出了一种用于计算DON精度的改进方法，该方法通过针对每个用于计算DON浓度的测得氮含量建立精度与浓度之间的经验关系，从而加强了常规误差的传播。由于每个样品中每个测得的氮含量的浓度和相对重要性不同，因此每个样品的DON精度和相应的检测限可能会有所不同。来自两个不同研究工作的案例研究，对地表水DON的天气学研究和对从热处理土壤中沥出的DON进行的实验评估表明，如何针对所研究项目的预期分析方法和浓度范围调整提议的方法。此外，应修改当前有关提高DON精度的预处理（例如，透析）建议，以考虑分析精度。改进的DON精度表征有助于对特定样品的检出限进行更现实的评估，并且可以对结果进行概括以支持有关DON数据的预处理和统计分析的决策。此外，应修改当前有关提高DON精度的预处理（例如，透析）建议，以考虑分析精度。改进的DON精度表征有助于对特定样品的检出限进行更现实的评估，并且可以对结果进行概括以支持有关DON数据的预处理和统计分析的决策。此外，应修改当前有关提高DON精度的预处理（例如，透析）建议，以考虑分析精度。改进的DON精度表征有助于对特定样品的检出限进行更现实的评估，并且可以对结果进行概括以支持有关DON数据的预处理和统计分析的决策。