Comparison of chromium determination in capsule shells by Zeeman flame and graphite furnace atomic absorption spectrophotometry

Objective:To investigate effects of Zeeman flame atomic absorption spectrophotometry(AAS) and graphite furnace AAS on the determination of chromium in capsule shells.Methods:Microwave digestion was adopted to digest the capsule shells.Zeeman effect was used in the background correction.The slit width was set at 1.3 nm,lamp current 7.5 mA,and the content of chromium was determined at a wavelength of 359.3 nm by Zeeman flame AAS and graphite furnace AAS respectively.Results:For the Zeeman flame AAS method,the calibration curve was linear in the range of 0-1.0 μg·mL-1(r=0.9998),the detection limit was 5.26 ng·mL-1,RSD was 0.68%-1.0% and the average recovery was 100.0%-116.7%.For the graphite furnace AAS method,the calibration curve was linear in the range of 0-20 ng·mL-1(r=0.9999),the detection limit was 0.26 ng·mL-1,RSD was 1.7%-4.9% and the average recovery was 98.2%-105.6%.Conclusion:The Zeeman flame AAS method is simple,fast,and suitable for the preliminary determination of chromium in capsule shells in emergent cases;the graphite furnace AAS method is sensitive,accurate,and suitable for the determination of chromium in capsule shells in any case.