One of our long standing customers recently had a new project and needed us to analyse their samples in duplicate for C, H, N, S and iodine. They explained that they would have many such samples for the same analysis over the coming months, but would also need a same-day service on many of the iodine tests.

Iodine analysis is carried out by titration with sodium thiosulphate following combustion in an oxygen flask. However to prevent loss of iodine from the flask and absorption solution the whole must be kept ice-cold during the subsequent analysis. This normally limits the number of analyses that can be conducted during a day as rushing the procedure merely generates inaccurate results. However by investing in additional Schöniger flasks and platinum combustion baskets we were able to double the possible throughput and so keep the customer happy.

The C, H, N and S analysis is performed by elemental combustion using a Thermo FlashEA 1112 elemental analyser. We use Sartorius Cubis seven figure microbalances for all micro-analytical weighings, and once the samples have been weighed into tin capsules and placed in the autosampler the analyser can operate unattended overnight. Both the balances and analyser allow a high throughput and enable CHNS results to be  generated quickly and accurately.