X-Vane: A sampling assembly combining a Niskin-X bottle and titanium frame vane for trace metal analysis of sea water

Abstract

A new sampling assembly consisting of a commercially available 5-L Niskin-X sampling bottle attached to a titanium frame vane was designed for uncontaminated sampling of trace metals in sea water at volumes of 5L per depth. The assembly, called an X-Vane sampler, consists of a titanium and polyvinyl chloride (PVC) polymer supporting frame, a “Π-style” secure bottle assembly and secure messenger assembly with titanium springs, a polycarbonate weather vane rear fin assembly, a commercially available modified 5-L Niskin-X bottle, a small temperature and depth (TD) logger, and a nylon and stainless steel wire clamp. The X-Vane sampler permits positioning the Niskin-X bottle at upstream of the hydrowire, away from any contamination. The Teflon-coated messenger strikes the “Π-style” assembly, which closes the Niskin-X, thereby obtaining a sea water sample for trace metal analysis at the desired depth. A second messenger held by the “Π-style” assembly is released downward along the hydrowire. In this manner, several bottles can be triggered sequentially in one operation. The Niskin-X bottles are stored and processed in a PVC clean sample drawing enclosure with a clean environment created by three class-100 air filter vents. The X-vane sampling system is easy to operate and is low in cost, compared to other clean sampling methods. In addition, it can be adapted to different types of research vessels with different hydrowire conditions. Analyses of contamination-prone trace metals (Fe, Al, and Mn) showed that samples obtained using the X-Vane sampler were uncontaminated, and the analysis results were in good agreement with those for samples obtained using a MITESS-Vane sampler. The X-Vane sampling device was demonstrated to be a reliable device for obtaining sea water samples for trace metal analysis.