School of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, China.
College of Oceanography and Ecological Science, Shanghai Ocean University, Shanghai 201306, China E-mail:
Water Sci Technol. 2024 Apr;89(8):2060-2072. doi: 10.2166/wst.2024.114. Epub 2024 Apr 4.
A wet chemical oxidation (WCO) method has been widely used to obtain the dissolved organic carbon (DOC) content and carbon isotope (C) ratios. However, it is sometimes difficult to get high precision results because not enough CO was oxidized from the natural water samples with low DOC concentrations. This improvement primarily aims to increase the water sample volume, improve the removal rate of dissolved inorganic carbon (DIC), and minimize the blank DOC from the standard solution. Following the improved procedure, the C ratios of standardized DOC solutions were consistent with their actual values, and their differences were less than 0.2‰. The improved method demonstrated good accuracy and stability when applied to natural water samples with DOC concentrations ≥0.5 mg L, with the precisions of DOC concentrations and C ratios were better than 0.07 mg L and 0.1‰, respectively. More importantly, this method saved much pre-treatment time and realized batch processing of water samples to obtain their DOC contents and isotope ratios.
一种湿式化学氧化（WCO）方法已被广泛用于获得溶解有机碳（DOC）含量和碳同位素（C）比值。然而，由于从低 DOC 浓度的天然水样中氧化的 CO 量不足，有时很难获得高精度的结果。本改进方法主要旨在增加水样体积，提高溶解无机碳（DIC）的去除率，并尽量减少标准溶液中的空白 DOC。采用改进后的程序，标准化 DOC 溶液的 C 比值与其实际值一致，其差值小于 0.2‰。当应用于 DOC 浓度≥0.5mg/L 的天然水样时，改进后的方法具有良好的准确性和稳定性，DOC 浓度和 C 比值的精密度分别优于 0.07mg/L 和 0.1‰。更重要的是，该方法节省了大量的预处理时间，并实现了水样的批量处理，以获得其 DOC 含量和同位素比值。
