Comparison of pyrolysis-mass spectrometry with high performance liquid chromatography for the analysis of vancomycin in serum

Mass spectrometry coupled with a pyrolysis inlet system (Pyr-ms) is compared with high performance liquid chromatography (HPLC) for the determination of vancomycin and its crystal degradation products (CDP-Is) in human serum. Quantitative analysis of Pyr-ms was performed by selected ion monitoring (SIM) method at 108 mass:charge (m/z) of pyrolysis product of vancomycin. 3-Nitroaniline (138 m/z) was used as an internal standard. A mu -Bondapak C-18 column and the gradient mobile phase of triethylamine buffer (pH 6.2), acetonitrile and tetrahydrofuran and a photometric detection at 205 mn are found to be the optimum conditions for the HPLC determination of vancomycin and CDP-Is. The limit of detection (LOD = I ng ml(-1)), linearity (I ng ml(-1)-10 mg ml(-1)), relative standard deviation (R.S.D. = 1%), time analysis (1/2 h) and sample volume (50 mul) of Pyr-ms are far better than of the HPLC method. However, the HPLC method can individually determine the concentration of vancomycin and its degradation products. (C) 2001 Elsevier Science B.V. All rights reserved.