Objective:To establish an atomic absorption spectrometry method for the determination of lead and ferrum in pre-mix-ture coating film. Methods:The samples were digested by microwave digestion system, and Pb was determined by graphite atomic ab-sorption spectrometry(GFAAS), and Fe was determined by flame atomic absorption spectrometry(FAAS). Results: There was good linear relationship within the range of 1.0-5.0 μg·L-1(r=0.999 4) for lead and 0.1-1.0 mg·L-1(r=0.998 4) for ferrum. The recovery of lead was 91. 3%(RSD=1. 4%,n=9)and that of ferrum was 89. 9%(RSD=3. 5%,n=9). Conclusion: The method is accurate and stable, which can be used for the determination of lead and ferrum in pre-mixture coating film

Objective: To establish an HPLC method for the determination of three bacteriostatic agents ( methylparaben, eth-ylparaben, propylparaben) in taurine eye drops. Methods:The HPLC method was conducted on a Phenomenex Gemini C18 column ( 250 mm × 4. 6 mm, 5 μm ). The mobile phase was 1％ acetic acid-methanol(40 :60). The flow rate was 1. 0 ml·min-1 and the de-tection wavelength was 254 nm with the injection volume of 20 μl and the column temperature of 25℃. Results:Methylparaben, eth-ylparaben and propylparaben showed good linear relationship (r>0. 999)within the range of 1. 00-19. 94μg·ml-1,2. 01-20. 08μg· ml-1 and 0. 21-10. 46 μg·ml-1,respectively. The average recoveries were 99. 20％-99. 90％, and the RSDs were 1. 34％-1. 54％(n=9). Conclusion:The method is accurate, reproducible and stable without interference, which can be used for the determination of three bacteriostatic agents in taurine eye drops.

Objective:To develop a method for the determination of potassium sorbate in Xiao 'er Kechuanling oral solution by HPLC.Methods:A Phenomenex Gemini C18 column (250 mm ×4.6 mm, 5 μm) was used, and the mobile phase was 0.02 mol· L-1 sodium dihydrogen phosphate (adjusting pH to 4.0 with phosphoric acid)-acetonitrile (80:20).The flow rate was 1.0 ml· min-1 and the detection wavelength was set at 262 nm.The column temperature was 30℃and the injection volume was 20μl.Results:The linear range of potassium sorbate was 8.584-85.840μg· ml-1(r=0.9999).The recovery of potassium sorbate was 100.0％and the RSD was 0.47％(n=9).The limit of detection was 0.43 ng and the limit of quantitation was 1.29 ng.Conclusion:After the valida-tion, the method can be used for the assay of potassium sorbate in Xiao'er Kechuanling oral solution .