Solid phase extraction for an improved assay of physostigmine in biological fluids

✍ Scribed by P. R. Hurst; R. Whelpton

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 658 KB
• Volume: 3
• Category: Article
• ISSN: 0269-3879
• DOI: 10.1002/bmc.1130030511

✦ Synopsis

A simple, selective and very sensitive assay is described for the quantification of physostigmine in blood, plasma and urine. The most appropriate solid phase column was selected after a systematic investigation of nine types of phase. The conditions for solid phase extraction were optimized using ['Hlphysostigmine so that the overall recoveries were >90%. Physostigmine was retained on alkaline treated cyanopropyl columns and eluted into the minimum volume of methanol, obviating the need for an evaporation step. Extracted samples were quantified by HPLC with a three electrode coulometric detection system. The limit of detection was 50 pg/mL for a 0.5 mL plasma sample. The precision (CV) for 0.5 mL plasma samples containing 50 pg was 8.1%. Application of the method to plasma, blood and urine samples is presented. of physostigmine (Whelpton and Moore, 1985), neostigmine bromide was added to give a final concentration of 10 pg/mL, before any addition of physostigmine. Unknown blood and