岩矿测试2024，Vol.43Issue(6)：914-927,14.DOI:10.15898/j.ykcs.202405130108
湿氧化法测定岩溶区水体中溶解有机碳同位素的影响因素研究
Influencing Factors of Dissolved Organic Carbon Isotope Determination in Water Samples of a Karst Area by Wet Oxidation Method
摘要
Abstract
Due to the high content of H CO3-,low content of DOC and complex composition in the karst water,the current wet oxidation method for the determination of δ13CDoC needs to be improved.The study examined the impact of different pure waters,headspace bottle atmospheric equilibrium methods,DOC content,and the removal of bicarbonate(HCO3-)in water on δ13CDOC values.The experimental results show significant differences in the 44CO2 peak areas produced by different blank pure waters,with the most prominent peak area being 3.8 times the smallest.Using a gas-tight syringe for atmospheric equilibrium enhances the sample signal strength and ensures the optimal internal precision of the sample test results.Acidifying the water samples to pH＜3 with phosphoric acid eliminates the influence of HCO3-in karst waters.A nitrogen-blowing apparatus at a 250mL/min flow rate for 5-10min removes the free CO2 present after acidification.Under the above experimental conditions,the deviation between the test results and the calibrated reference values for karst water samples with DOC content greater than 2mg/L is better than 0.40‰ after blank correction.The difference in the measured results of δ13CDoC in karst water samples measured by the wet oxidation method compared to the total organic carbon analyzer-stable isotope mass spectrometer online method was less than 0.30 ‰.The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202405130108.关键词
溶解有机碳/碳酸氢根/湿氧化法/同位素质谱法/空白样品Key words
dissolved organic carbon/HCO3/wet oxidation method/isotope mass spectrometry/blank sample分类
化学化工引用本文复制引用
杨会,吴夏,俞建国,唐伟,蓝高勇..湿氧化法测定岩溶区水体中溶解有机碳同位素的影响因素研究[J].岩矿测试,2024,43(6):914-927,14.基金项目
国家自然科学基金项目(41501222) （41501222）
广西自然科学基金项目(2018GXNSFBA138042,2018GXNSFAA281320) （2018GXNSFBA138042,2018GXNSFAA281320）
中国地质科学院岩溶地质研究所基本科研业务费项目(2023015,2023018) （2023015,2023018）
浙江省地质碳汇调查、监测与应用试点项目(浙地质函[2024]35号) （浙地质函[2024]35号）
