Biogeochemistry and characteristics of dissolved organic matter (DOM), which is ubiquitous in aquatic ecosystems, arises wide interests of researchers, especially in the fields of environmental and marine sciences. Insufficient DOM samples hamper our instrumental analyses, especially at the molecular level, using state-of-the-art analytical techniques, e.g., NMR, FTICR-MS, elemental and isotopic analyses, etc. High salinity of seawater, low DOC concentration, less amount of water, and highly hydrophilic nature of marine DOM compounds lead low DOC recoveries, high ash and insufficient amounts of samples (for freeze-dried products) using traditional resin techniques of isolation and extraction. By far. PPL-based solid phase extraction to process a large volume of seawater is considered as the top priority, with DOC recovery (~55-60%), low ash and good resin repeatability. However, it is laborious to process large volume of waters with possible contamination of containers, shipping difficulty, time-consuming in the land-based laboratory. To overcome these problems, currently we are trying to develop an in-site device to isolate DOM from surface water. This project aims to develop an in-situ compact device (in a perspex box, water proof) that are comprised of five sections: (1) water filtration; (2) water pumping; (3) glass column; (4) in-line acidity regulator and acid/base neutralization (5) automatic monitoring. The device is power by a portable AC power supply or from a nearby offshore platform. This device is designed to work a period of 24/7. The flow rate is about 60~80 ml/min, with a glass column of 3 cm in diameter and 30 cm in length. The total g capacity is supposed to 600~800 L in the first run. This approach to adsorb DOM in a PPL-resin column would be affordable, non-destructive, and easily deployed in a field setting. In a summary, the project has two parts, one to show that the isolation part could adsorb marine DOM in-situ and another to show that the site situation could be monitored in the office. The DOC recoveries and repeatability for a series batch waters will be tested for its reliability.