Hussain F N, Ajjan R A, Moustafa M, Anderson J C, Riley S A
Department of Gastroenterology, Northern General Hospital, Sheffield, UK.
J Chromatogr B Biomed Sci Appl. 1998 Sep 25;716(1-2):257-66. doi: 10.1016/s0378-4347(98)00323-5.
We describe a sensitive high-performance liquid chromatographic method for the determination of 5-aminosalicylic acid and N-acetyl-5-aminosalicylic acid in rectal tissue biopsies. Samples were derivatised using propionic anhydride and proteins were precipitated with methanol. A Supelcosil ABZ column (150x4.6 mm I.D., 5 microm silica particles) was used with a mobile phase comprising 0.1 M acetic acid, acetonitrile and triethylamine (1600:114:6, v/v/v). Fluorescence detection was employed and detection limits were 0.2 ng/mg tissue at a signal-to-noise ratio of three (measured concentration: 5-aminosalicylic acid, 0.254 (0.228-0.286) ng/mg, C.V. 10.7%; N-acetyl-5-aminosalicylic acid, 0.18 (0.154-0.198) ng/mg, C.V 9.8%). This assay was validated for use with serum, urine and faecal samples for which it proved to be both precise and accurate (C.V.<10%, measured concentration within 10%).
