基于^(18)O法利用膜进样质谱仪测定海水初级生产力的方法优化及在长江口的应用  

OPTIMIZATION OF THE ^(18)O METHOD FOR DETERMINING PRIMARY PRODUCTIVITY OF SEAWATER USING MEMBRANE INLET MASS SPECTROMETRY AND ITS APPLICATION IN THE CHANGJIANG RIVER ESTUARY

作　　者：张玉寒 宋国栋[1,2] 张桂玲 刘素美[1,2] ZHANG Yu-Han;SONG Guo-Dong;ZHANG Gui-Ling;LIU Su-Mei(Frontiers Science Center for Deep Ocean Multispheres and Earth System/Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education,Ocean University of China,Qingdao 266100,China;Laboratory for Marine Ecology and Environmental Science,Qingdao Marine Science and Technology Center,Qingdao 266237,China;College of Chemistry and Chemical Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学深海圈层与地球系统前沿科学中心/海洋化学理论与工程技术教育部重点实验室,山东青岛266100 [2]青岛海洋科技中心海洋生态与环境科学功能实验室,山东青岛266237 [3]中国海洋大学化学化工学院,山东青岛266100

出　　处：《海洋与湖沼》2024年第5期1163-1171,共9页Oceanologia Et Limnologia Sinica

基　　金：国家自然科学基金,42076035号,42376044号,U1806211号;泰山学者项目。

摘　　要：浮游植物的初级生产对海洋碳循环起着至关重要的作用,准确测定海洋初级生产力是评估海洋固碳能力的关键。^(18)O法可获得准确的总初级生产力,但其复杂的测定方法限制了现场应用,快速测定^(18)O标记的产物(^(34)O_(2))是实现^(18)O法广泛应用的关键。研究利用自组装膜进样质谱仪基于^(18)O标记技术测定水体初级生产力,对膜进样质谱仪分析^(34)O_(2)的测量条件以及^(18)O法培养过程进行了优化。结果表明,在进样流速为0.85~1.05 mL/min,进样时间为3~4 min,恒温槽温度为15~20℃的条件下,^(34)O_(2)/^(32)O_(2)的测试精密度为0.1%~0.2%,比较适合^(34)O_(2)的测定,在H_(2) ^(18)O与水样体积比为(2.1×10^(−3))~(3.4×10^(−3)),培养时间为6 h的培养条件下,可以获得比较满意的总初级生产力的测试结果。利用优化后的方法对春季长江口的初级生产力测试表明:总初级生产力和净群落生产力变化范围分别为0.11~1.20 mmol O2/(m^(3)∙h)、−1.60~0.75 mmol O_(2)/(m^(3)∙h),水柱总初级生产力为(671.5±117.1)~(2339.8±260.7)mg C/(m^(2)∙d),最大固碳能力为1056.9±662.4 mg C/(m^(2)∙d),与文献报道结果较为一致,高值区位于远离长江口的浅海水和外海水混合区。The primary production of phytoplankton is crucial to the carbon cycle in ocean.Accurate measurement of primary production is important to assess marine carbon fixation rate.The gross primary production can be obtained accurately by the ^(18)O method.However,the technical difficulties in handling and analysis of ^(18)O-enriched samples limited in-situ application of the ^(18)O method.Therefore,rapid determination of ^(18)O-labeled gas(^(34)O_(2))is crucial for the promotion of the ^(18)O method.Therefore,the operating condition of analyzing the ^(18)O-enriched samples by self-assembled membrane inlet mass spectrometry and incubation procedures for ^(18)O method were optimized.Results show that the precision of measured ^(34)O_(2)/^(32)O_(2) was 0.1%~0.2%under optimal operating conditions of inlet flow rate at 0.85~1.05 mL/min,sampling time at 3~4 min,and thermostat bath temperature at 15~20°C,which is suitable for the determination of ^(34)O_(2).In addition,satisfactory results for gross primary production were obtained when the volume ratio of H_(2)^(18)O to water sample in the incubation bottle was 2.1×10^(3)~3.4×10^(3) and the incubation time was 6 h.Primary production in the estuary in spring was measured using the optimized method.Results show that the gross primary production and net community production ranged 0.11~1.20 mmol O_(2)/(m^(3)·h)and−1.60~0.75 mmol O_(2)/(m^(3)·h),respectively.The range of variation in depth-integrated gross primary production was(671.5±117.1)~(2339.8±260.7)mg C/(m^(2)·d),and the maximum carbon fixation rate was 1056.9±662.4 mg C/(m^(2)·d),which are consistent with the results from available published data.The high primary production area is located at the confluence of shallow seawater from the shelf and seawater from the open sea away from the Changjiang River estuary.

关 键 词：^(18)O法 初级生产力 膜进样质谱仪 长江口 

分 类 号：P734[天文地球—海洋化学]