Onboard analysis of dissolved zinc everywhere in the open ocean with a Lab on Valve (LOV) system of the size of a bottle of wine is becoming possible

Thanks to the work of Maxime Grand and collaborators (2016, see reference below), it is now possible to analyse dissolved zinc (DZn) on board, from any kind of seawater using a “Lab On Valve (LOV)” method. For the first time, automated matrix removal, extraction of the target element, and fluorescence detection have been performed within a miniaturized flow manifold. The original flow programming is designed to pass sample through a minicolumn where the target analyte and other complexable cations are retained, while the seawater matrix is washed out. Once eluted, Zn is merged with a Zn selective fluorescent probe (FluoZin-3) prior to fluorescence detection in the LOV flow cell. This new shipboard method features a detection limit of 0.02 nM and a reagent consumption of 150 microliters per sample.

Successful comparison with GEOTRACES reference standards and analytical comparison with inductively coupled plasma mass spectrometry (ICPMS) eventually validate this beautiful, tiny and robust method.

16 Grandetal
Figure: A close up of the Lab-On-Valve (LOV) module, where microliter volumes of fluids are manipulated prior to fluorescence detection in the LOV flow cell (red circle). Right: Comparison of DZn profiles from the South Indian Gyre analysed via LOV and ICPMS.


Grand, M. M., Chocholouš, P., Růžička, J., Solich, P., & Measures, C. I. (2016). Determination of trace zinc in seawater by coupling solid phase extraction and fluorescence detection in the Lab-On-Valve format. Analytica Chimica Acta, 923, 45–54. doi:10.1016/j.aca.2016.03.056


Latest highlights

The development of the modern Antarctic Circumpolar Current occurred much later than previously thought!

This study is challenging the belief that the onset of the Antarctic Circumpolar Current was solely triggered by the opening and deepening of Southern Ocean Gateways.

A dynamic iron cycle in Peru

Gu and colleagues explore the temporal variation of iron over 11 cruises along the Peruvian shelf.

Trace metal fluxes of cadmium, copper, lead and zinc from the Congo River into the South Atlantic Ocean are supplemented by atmospheric inputs

Liu and colleagues show that rainfall augments some fluxes of trace metals from the Congo River.

Aluminium, manganese, iron, cobalt, and lead display contrasting fate along north–south and east–west sections in the North Pacific Ocean

Chan et co-authors provide a comprehensive view of trace metal distribution in the subarctic Pacific Ocean.