Iron pentacarbonyl determination in carbon monoxide

Iron pentacarbonyl, Fe(CO)(5), was previously employed to calibrate the sea led inductively coupled plasma (SICP) for Fe in a 50% chlorine discharge. T he same technique is used to determine Fe as Fe(CO)(5), one of the most imp ortant metallic compound impurities present, in carbon monoxide cylinders. Iron concentrations in various CO cylinders were determined directly by SIC P in 30% (v/v) CO. Operating parameters including incident power and maximu m tolerable CO and Cl-2 concentrations in the discharge were optimized. The detection limit for Fe(CO)(5) in CO was 0.18 mu l l(-1) (172 ng absolute). Statistically similar results were obtained when Fe(CO)(5) content was det ermined by FTIR and SICP-AES. Two- and sevenfold increases in Fe(CO), conce ntrations were observed over a 1-year period in two different carbon steel cylinders containing CO. (C) 1999 Elsevier Science B.V. All rights reserved .