Mixed-mechanism ionization to enhance sensitivity in atmospheric pressure ionization LC/MS.
J Pharm Biomed Anal
; 22(5): 861-7, 2000 Jun.
Article
en En
| MEDLINE
| ID: mdl-10815727
ABSTRACT
A novel dual-mechanism ionization technique for LC/MS/MS has been observed, characterized and applied to the quantitation of a tertiary amine-containing drug compound in dog plasma. This mixed-mechanism ionization approach can improve the sensitivity of the pneumatically assisted electrospray experiment. Under conditions of higher than normal chromatographic flow and lower electrospray voltage, approximately a 4-fold increase in sensitivity was realized. A detection limit of 16 pg (45 fmol) on-column, and inter-day imprecision and inaccuracy of < 11 and < 15%, respectively, were obtained. A trade-off in concentration sensitivity in favor of ease of sample preparation was made to increase sample throughput. Although results strongly suggest that mixed-mechanism ionization is in operation, and that pneumatically assisted electrospray is a partial contributor to the overall ionization process, the exact nature of the second mechanism of ionization is unclear at this time.
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Bases de datos:
MEDLINE
Asunto principal:
Espectrometría de Masas
/
Cromatografía Liquida
/
Sensibilidad y Especificidad
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Pharm Biomed Anal
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos