Today I visited the Voltammetry Lab again to ask how things are going so far. After a couple of very busy water sampling days, the lab was quieter, but this was only because they were deep into their onboard analyses of titanium and nickel.
They told me that once the initial teething troubles were over, requiring them to calibrate the equipment and effect some repair and maintenance on a few items, they quickly settled into an efficient routine. They reflected that the water sampling organisation onboard was somewhat different from the previous Geotraces cruise (M147), but seemed to be working well, and there was a good deal of cooperation between the various teams. Indeed Cristian had been able to assist with some of the sampling routines, helping to maintain a smooth flow of sample water for filtration.
Alexandre was good enough to show me in some detail how the equipment works that they use in their DPAdCSV (I’ve been trying to memorise this for two weeks, but have failed totally – you will obviously know that it stands for Differential Pulse Adsorptive Cathodic Stripping Voltammetry). Rather than go into too much detail (cough), I’ll let you watch the video. It is of course very early for them to say much about the data they have collected, and much of the detailed analysis will only be done in the home lab. However, Alexandre reported that initial findings showed the amount of titanium found in samples was generally lower in the Pará transect than in 2018, which he attributes to the fact that there is now a much lower flow of freshwater into the estuary than at high water. He found little difference in the mangrove transect. On the other hand, Leandro had observed an increase in the concentration of nickel, which again may be attributable to the reduced flow of freshwater. In both cases, they are keen to get some samples from further into the river, if we are able to enter the northern Macapá channel.
Everyone agreed that there was the same level of friendly cooperation amongst all the teams and with the Captain and crew of the Meteor, and I’m happy to confirm this. Thanks for your time, guys. 🙂