interday repeatability.
2.3. Instrument Parameters
Various parameters were tested using human blood, until a method which provided acceptable recovery and preci-sion was found. These parameters included changes to sample volume and drying/decomposition conditions. EPA method 7473 was used as a starting point, as it had previously been validated as an effective and reliable method to measure mercury in fish tissues [10]. A me- thod provided by the manufacturer was also considered, but found unsuitable for whole blood analysis. With lar-ger number of samples, this method resulted in residue accumulation in the catalyst tube and cells, wearing down the mercury vapor lamp and ultimately resulting in greater uncertainty between duplicate samples.