Underway Measurement of Dissolved Inorganic Carbon (DIC) in Estuarine Waters
Dissolved inorganic carbon (DIC) is an important parameter of the marine carbonate system. Underway analyses of DIC are required to describe spatial and temporal changes of DIC in marine systems. In this study, we developed a microvolume flow detection method for the underway determination of DIC in...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-09-01
|
| Series: | Journal of Marine Science and Engineering |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2077-1312/8/10/765 |
| _version_ | 1797552168616591360 |
|---|---|
| author | Jinpei Yan Qi Lin Seng Chee Poh Yuhong Li Liyang Zhan |
| author_facet | Jinpei Yan Qi Lin Seng Chee Poh Yuhong Li Liyang Zhan |
| author_sort | Jinpei Yan |
| collection | DOAJ |
| description | Dissolved inorganic carbon (DIC) is an important parameter of the marine carbonate system. Underway analyses of DIC are required to describe spatial and temporal changes of DIC in marine systems. In this study, we developed a microvolume flow detection method for the underway determination of DIC in marine waters, using gas-diffusion flow analysis in conjunction with electrical conductivity (EC) measurement. Only an acid carrier reagent (0.2 mol.L<sup>−1</sup>) and an ultrapure water acceptor are required for the DIC monitoring system. In this system, a sampling loop (100 µL) is used to quantify the injection sample volume, allowing micro-sample volume detection. The water sample reacts with the acid reagent to convert carbonate and bicarbonate species into CO<sub>2</sub>. The water sample is then carried into a gas-diffusion assembly, where the CO<sub>2</sub> diffuses from the sampling stream into the acceptor stream. CO<sub>2</sub> in the acceptor is detected subsequently by an electrical conductivity. The limit of DIC detection using ultrapure water is 0.16 mM. A good repeatability is obtained, with a relative standard deviation (RSD) of 0.56% (1 mM, n = 21). The time interval for detecting one sample is 5 min. During the observation period, measurements can be switched between standard solutions and water samples automatically. Accuracy and precision of the instrument is sufficient for the underway observation of marine DIC in estuarine waters. |
| first_indexed | 2024-03-10T15:56:09Z |
| format | Article |
| id | doaj.art-aa3f8f1e3592434c920a1ff681b5aae5 |
| institution | Directory Open Access Journal |
| issn | 2077-1312 |
| language | English |
| last_indexed | 2024-03-10T15:56:09Z |
| publishDate | 2020-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Marine Science and Engineering |
| spelling | doaj.art-aa3f8f1e3592434c920a1ff681b5aae52023-11-20T15:39:49ZengMDPI AGJournal of Marine Science and Engineering2077-13122020-09-0181076510.3390/jmse8100765Underway Measurement of Dissolved Inorganic Carbon (DIC) in Estuarine WatersJinpei Yan0Qi Lin1Seng Chee Poh2Yuhong Li3Liyang Zhan4Key Laboratory of Global Change and Marine Atmospheric Chemistry, MNR, Xiamen 361005, ChinaKey Laboratory of Global Change and Marine Atmospheric Chemistry, MNR, Xiamen 361005, ChinaFaculty of Science and Marine Environment, Universiti Malaysia Terengganu, Terengganu 21030, MalaysiaKey Laboratory of Global Change and Marine Atmospheric Chemistry, MNR, Xiamen 361005, ChinaKey Laboratory of Global Change and Marine Atmospheric Chemistry, MNR, Xiamen 361005, ChinaDissolved inorganic carbon (DIC) is an important parameter of the marine carbonate system. Underway analyses of DIC are required to describe spatial and temporal changes of DIC in marine systems. In this study, we developed a microvolume flow detection method for the underway determination of DIC in marine waters, using gas-diffusion flow analysis in conjunction with electrical conductivity (EC) measurement. Only an acid carrier reagent (0.2 mol.L<sup>−1</sup>) and an ultrapure water acceptor are required for the DIC monitoring system. In this system, a sampling loop (100 µL) is used to quantify the injection sample volume, allowing micro-sample volume detection. The water sample reacts with the acid reagent to convert carbonate and bicarbonate species into CO<sub>2</sub>. The water sample is then carried into a gas-diffusion assembly, where the CO<sub>2</sub> diffuses from the sampling stream into the acceptor stream. CO<sub>2</sub> in the acceptor is detected subsequently by an electrical conductivity. The limit of DIC detection using ultrapure water is 0.16 mM. A good repeatability is obtained, with a relative standard deviation (RSD) of 0.56% (1 mM, n = 21). The time interval for detecting one sample is 5 min. During the observation period, measurements can be switched between standard solutions and water samples automatically. Accuracy and precision of the instrument is sufficient for the underway observation of marine DIC in estuarine waters.https://www.mdpi.com/2077-1312/8/10/765dissolved inorganic carbon (DIC)underway measurementconductivity detector |
| spellingShingle | Jinpei Yan Qi Lin Seng Chee Poh Yuhong Li Liyang Zhan Underway Measurement of Dissolved Inorganic Carbon (DIC) in Estuarine Waters Journal of Marine Science and Engineering dissolved inorganic carbon (DIC) underway measurement conductivity detector |
| title | Underway Measurement of Dissolved Inorganic Carbon (DIC) in Estuarine Waters |
| title_full | Underway Measurement of Dissolved Inorganic Carbon (DIC) in Estuarine Waters |
| title_fullStr | Underway Measurement of Dissolved Inorganic Carbon (DIC) in Estuarine Waters |
| title_full_unstemmed | Underway Measurement of Dissolved Inorganic Carbon (DIC) in Estuarine Waters |
| title_short | Underway Measurement of Dissolved Inorganic Carbon (DIC) in Estuarine Waters |
| title_sort | underway measurement of dissolved inorganic carbon dic in estuarine waters |
| topic | dissolved inorganic carbon (DIC) underway measurement conductivity detector |
| url | https://www.mdpi.com/2077-1312/8/10/765 |
| work_keys_str_mv | AT jinpeiyan underwaymeasurementofdissolvedinorganiccarbondicinestuarinewaters AT qilin underwaymeasurementofdissolvedinorganiccarbondicinestuarinewaters AT sengcheepoh underwaymeasurementofdissolvedinorganiccarbondicinestuarinewaters AT yuhongli underwaymeasurementofdissolvedinorganiccarbondicinestuarinewaters AT liyangzhan underwaymeasurementofdissolvedinorganiccarbondicinestuarinewaters |