[Determination of chromium in capsule by inductively coupled plasma-mass spectrometry]

To establish the method which determined the content of chromium(Cr) in capsule by inductively coupled plasma-mass spectrometry.

Pre-digestion-microwave digestion procedures were applied to extract Cr from the capsules. The potentially interfering 40Ar12C+ and 37Cl16O+ at the chromium masses m/z 52 and 53 were reduced in intensity by approximately 2 orders of magnitude by using 0. 6 ml/min NH3 as reactive cell gas in the dynamic reaction cell (DRC) while a Rpq value of 0.55 was used.

The correlation coefficient (r) of standard curve was 0.9996, and the detection limit of the method was 0.03 mg/kg, and the average recoveries for all determinations ranged from 86.5% to 107.8% with the related standard deviation below 5%.

The method, which is of good precision and accuracy, is applicable to rapid and accurate determination of chromium content in capsule.