Liquid samples must be carefully sealed prior to shipment. It is necessary to fill vials completely to avoid possible isotopic fractionation due to evaporation processes in excess headspace within the individual vial. Please be sure to take extra precautions in shipping liquid samples. Be sure to package fragile glass vials tightly and safely. Water samples with a low pH (acidic) can cause damage to the ion source within the mass spectrometer. Be sure to discuss the possibility of very acidic or basic samples with COIL personnel prior to sending samples. Once the samples reach the facility, they are stored in a refrigerator until analysis. Typically 2-3 mL of water is sufficient for analysis.
Liquid sample preparation using the elemental analyzer is also a possibility. Liquid samples are pipetted into a tin capsule that contains an inert substance called Chromabsorb. The Chromabsorb soaks up the liquid preventing leakage from the capsule. The sample is then analyzed in the same way that solid samples are using the elemental analyzer peripheral. This method works well for semi-liquid samples such as oils.