Protocol for clumped isotopes - weighing and running measurements

Introduction

The following protocol describes how to weigh samples and run clumped isotopes measurements.

Safety Information
Wear cryo-gloves, long sleeve shirts, protection glasses and closed shoes when handling liquid nitrogen in open dewars. Liquid nitrogen is extremely cold. The vapor of liquid nitrogen can rapidly freeze skin tissue and eye fluid, resulting in cold burns, frostbite, and permanent eye damage even by brief exposure.
In the event of spillage of liquid nitrogen on a person: If exposed to liquid or cold gas, restore tissue to normal body temperature, 37°C, followed by protection of the injured tissue from further damage and infection. Remove or loosen clothing that may constrict blood circulation to the frozen area. Rapid warming of the affected part is best achieved by using water at 42°C. Water should under no circumstances be over 44°C, nor should the frozen part be rubbed either before or after rewarming. If in doubt contact Legevakt (phone 116 117 or 113 for emergencies).
If someone gets liquid nitrogen it in their eyes, call 113, wash the eyes with appropriate equipment immediately.

Sample identification and measurement sequence

A run list should first be made, using one of the worksheets in the weighing room (sheets labeled for mass spectrometer). Standards and samples in appropriate numbers and at appropriate positions should be filled in (some may already be listed). Project and project number for billing must be written when applicable.

Weighing in standards/sample material (usually the day before starting a run)

Equipment:

Spatula
tweezers
tray
brush
weighing boat
rack for sample vials, and
clean Kiel vials.

Write yourself on the calendar to book a balance in advance. Otherwise, check if the microscale is available.
Determine what mass range you need to use (dependent on run type).
Assemble necessary tools: picking tray, ‘mini-spoon’, brush, tweezers, weighing papers, weighing boat (small aluminium ones most appropriate), racks and appropriate vials.
Clean clumped isotope vials are found in the blue wire racks; NEVER use vials from somewhere else and never mix up clumped isotope vials with any others!
There must be two clean and empty vials at the beginning of the sample rack (pump vials used as place holders and for safety during a measurement run).
Clean the working bench and all weighing equipment with Kim Wipes/brush such that your working area is free from dust and the implements you will use to weigh are clean and free from contaminants.
Do not place vials, racks or other equipment on the anti-vibration table or on top of the microscale to prevent destabilizing the balance.