ANYL 85 |
| LC-MS/MS is one of the most commonly used techniques for analyzing small molecules in biological fluids. Optimization of LC conditions (pH, buffer composition and flow rate of the mobile phase) are required to improve the retention times and limits of quantitation (LOQ). Basic drugs spiked into bovine serum were extracted using an optimized SPE method with a mixed phase cation exchanger resin. LC separation was accomplished with a generic gradient using a mobile phase at low or high pH with additives such as formic acid, ammonia or formate buffer. Mobile phase pH and flow rate effects on retention times and signal intensity were analyzed using MS detection in single ion mode. The effect of mobile phase pH on LOQ was determined using Single Reaction Monitoring (SRM) under ESI+ ionization conditions. Improved retention and signal intensity in single ion mode was observed when using a high pH mobile phase. |
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General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Analytical Chemistry |