CTD water sampling for δ13C of DIC in seawater

Introduction

The following protocol describes the sampling of water from the Niskin bottles of onboard CTD equipment for δ13C analyses.

Safety info

Follow the ships rules for working in exposed areas. This can involve using helmet, floating vests etc. Often it is best to close the CTD hangar before sampling.

Wear lab coat, Nitrile gloves (TouchNTuff 92-600 or equivalent), protection glasses and closed shoes when handling HgCl2 solutions. Work on a designated area, with water absorbing bench paper with plastic coating towards the bench.

In the event of spillage of HgCl2 containing samples on a person

Remove items that you have spilt on immediately and rinse area that has been in contact with HgCl2 with water and soap for approximately 5 minutes. Watch to see in area becomes inflamed or irritated. If in doubt call giftkontrollen (22 59 13 00) or contact Legevakt (phone 116 117 or 113 for emergencies).

If HgCl2 containing solutions are ingested or someone get it in the eyes, call 113, wash the eyes with appropriate equipment immediately.

Samples will contain approximately 0.2 mg HgCl2 per ml or less. HgCl2 stock solution will be a saturated solution (7.4g/100 ml at 20C), often containing precipitated HgCl2.

Spillage and waste handling

If Hg containing liquids are spilled on benches or the floor etc., wipe with paper towels, and wash properly. Paper towels etc. are put in zip bags and in yellow special waste boxes.

Waste is stored and handled on shore.

All waste and consumables that have been in contact with HgCl2 should be packed in plastic bags and yellow special waste boxes.

Vials with Hg containing sample should be closed and packed so they will not break and be put in red hazardous waste boxes (https://www.uib.no/hms-portalen/74275/farlig-avfall) after analyses or sent back to sample owner. Remember to fill in and attach the declaration form.

Samples that are in reusable containers should be poured into a larger (e.g. 10L bucket) with approximately 100 ml (sorbent) and stirred over night. The water is then decanted out, and the sorbent is put in a closed container (e.g. plastic bottle) and put in red hazardous waste containers including a declaration form.