Accurate Determination of Fluoride, Chloride, and Sulfur at Trace Level (<100 ppb)

Combustion Ion Chromatography enables the determination of speciated halides and sulfur compounds by a single analysis. TE Instruments developed a fully automated, extremely compact sample preparation system covering the pyrohydrolytic combustion, fraction collection, and sample injection towards any IC. The XPREP C-IC is the only configuration capable of introducing liquid samples both via optimized direct injection module and conventional boat-inlet system into a horizontal furnace. Sample introduction by direct injection improves the analytical results for trace level applications such as aromatic hydrocarbons and ultrapure chemicals.

A larger sample volume (100 µL) can be introduced into the direct injection module compared with boat-inlet systems. Controlled sample evaporation at 1 µL/s eliminates the need for a boat program and decreases the time of sample combustion dramatically. Multiple sample combustions can be collected in the same absorption tube, which increases the concentration of analytes in the absorbance medium. The analytical results at trace level are significantly improved by adjusting the number of sample combustions, volume of absorbance liquid, size of the IC sample loop, and use of a pre-concentrator.

The XPREP C-IC sample preparation system was connected to a high-end IC to generate a fully automated C-IC configuration. Calibration standards made from Fluorobenzene (F), Chlorobenzene (Cl) and Dibenzothiophene (S) in Xylene were analyzed, covering a range of 25 – 100 ppb for each element. Excellent calibration line fits (>0.999 r2) were created by optimizing the number of sample combustions for each analysis. The table below demonstrates high precision of analyzed results at trace level (lower than 100 ppb), which is well below the scope of international test methods currently available such as ASTM D7359 and UOP 991.

Combustion IC - Total Fluoride, Chloride, and Sulfur at Trace Level

Peak Overlay Calibration Standards

Combustion IC - Total Fluoride, Chloride, and Sulfur at Trace Level