Trace anion determination in concentrated hydrofluoric acid solutions by two-dimensional ion chromatography II. Method performance study with a hydroxide eluent and a low noise suppressor.
The two-dimensional ion exclusion chromatography/ion chromatography (ICE-IC) approach is considered to be the method of choice for the determination of trace anions in concentrated hydrofluoric acid (48-50%, w/w). In order to achieve lower detection limits, this method was for the first time used with electrolytically generated and purified hydroxide eluents in combination with a low noise electrochemical suppressor. Compared to carbonate based eluents, the achieved gain in peak height sensitivity for chloride, sulfate, nitrate and phosphate is a factor of 6, 7, 16 and 13, respectively. The instrumental detection limits, based on the background noise, are 2, 0.2, 0.4 and 1.4 microg/kg HF 50% (w/w) for the same anions. Their method detection limits, calculated according to SEMI, are all within the 6-10microg/kg HF 50% (w/w) range and thus at least 10 times lower than the current Tier C grade requirements. The chromatographic run time could be shortened with some 10 min by the use of a relatively fast high-capacity hydroxide selective anion exchange column.
Vermeiren
K
K
SOLVAY Research & Technology, Analytical Technologies Competence Center, Ransbeekstraat 310, B-1120 Brussels, Belgium. Koen.Vermeiren@solvay.com
D000838:Anions / Q000032:analysis*; D002138:Calibration; D002712:Chlorides / Q000032:analysis; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D006858:Hydrofluoric Acid / Q000032:analysis* / Q000737:chemistry; D006878:Hydroxides / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D009566:Nitrates / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D015203:Reproducibility of Results; D013431:Sulfates / Q000032:analysis
D000838:Anions; D002712:Chlorides; D006878:Hydroxides; D007477:Ions; D009566:Nitrates; D010710:Phosphates; D013431:Sulfates; D006858:Hydrofluoric Acid