PMID- 10523774
OWN - NLM
STAT- MEDLINE
DCOM- 20000111
LR  - 20061115
IS  - 0951-4198 (Print)
IS  - 0951-4198 (Linking)
VI  - 13
IP  - 21
DP  - 1999
TI  - A new approach to the effective preparation of plasma samples for rapid drug 
      quantitation using on-line solid phase extraction mass spectrometry.
PG  - 2151-9
AB  - A procedure that permits rapid development of an optimized solid phase extraction 
      (SPE) method for the analysis of drugs in plasma by on-line solid phase 
      extraction-mass spectrometry (SPE-MS) has been developed. This procedure employs 
      the concept of manipulating the pH and the percentage of organic solvent in the 
      chromatographic mobile phase to affect the retention behaviors of both the matrix 
      components and the analytes of interest. This resulted in the effective removal 
      of matrix interferences from biological samples during SPE. During a the method 
      development, only generic HPLC gradient approaches were needed, and multiple 
      samples were pooled so that several SPE methods could be investigated at once. 
      The analysis time per sample was 1.3 minutes. Thus, the time involved in the 
      entire method development (analysis of a set of samples) was less than one hour. 
      With the knowledge of the retention behaviors of the analytes with respect to the 
      pH and the percentage of organic, it was then possible to compose an optimized 
      SPE-MS method. This method consisted of a base/organic and then an acid/organic 
      washing step, followed by a rapid gradient elution step. Due to the rigorous 
      washing procedure, most matrix interferences were removed, and analytes eluted 
      off the SPE sorbent suffered from very little matrix interference. Thus, 
      quantitation of drugs in plasma by a single quadrupole mass spectrometer could be 
      accomplished, something that was not possible when only a generic gradient was 
      used for on-line SPE-MS. In addition, both external and internal calibration 
      curves could be obtained for the concentration range from 5 to 500 ng/mL with 
      correlation coefficients of 0.99 (using 1/x as a weighting factor) and relative 
      standard deviations (RSDs) less than 10%. The results achieved were comparable to 
      those obtained by the use of a triple quadrupole mass spectrometer. Moreover, the 
      robustness of the method was tested by continuously injecting plasma samples. 
      During 136 runs, the absolute peak area variation for these three basic drugs was 
      less than 15% without taking the signal variation from the mass spectrometer into 
      account. Significantly, the on-line developed method can be directly transferred 
      to a 96-well format SPE plate.
CI  - Copyright 1999 John Wiley & Sons, Ltd.
FAU - Ding, J
AU  - Ding J
AD  - Waters Corporation, 34 Maple Street, Milford, MA 01757, USA. 
      jianmei_ding@waters.com
FAU - Neue, U D
AU  - Neue UD
LA  - eng
PT  - Journal Article
PL  - England
TA  - Rapid Commun Mass Spectrom
JT  - Rapid communications in mass spectrometry : RCM
JID - 8802365
RN  - 0 (Indicators and Reagents)
RN  - 0 (Pharmaceutical Preparations)
SB  - IM
MH  - Calibration
MH  - Chromatography, High Pressure Liquid
MH  - Hydrogen-Ion Concentration
MH  - Indicators and Reagents
MH  - Mass Spectrometry
MH  - Pharmaceutical Preparations/analysis
MH  - Plasma/*chemistry
MH  - Reference Standards
EDAT- 1999/10/19 00:00
MHDA- 1999/10/19 00:01
CRDT- 1999/10/19 00:00
PHST- 1999/10/19 00:00 [pubmed]
PHST- 1999/10/19 00:01 [medline]
PHST- 1999/10/19 00:00 [entrez]
AID - 10.1002/(SICI)1097-0231(19991115)13:21<2151::AID-RCM767>3.0.CO;2-E [pii]
AID - 10.1002/(SICI)1097-0231(19991115)13:21<2151::AID-RCM767>3.0.CO;2-E [doi]
PST - ppublish
SO  - Rapid Commun Mass Spectrom. 1999;13(21):2151-9. doi: 
      10.1002/(SICI)1097-0231(19991115)13:21<2151::AID-RCM767>3.0.CO;2-E.