Evaluation of a dual electrospray ionization/atmospheric pressure chemical ionization source at low flow rates (∼50 µL/min) for the analysis of both highly and weakly polar compounds

摘要: The atmospheric pressure ionization (API) source for a commercial mass spectrometer was modified to operate as dual in both the electrospray (ESI) and chemical (APCI) techniques by simultaneously utilizing probe corona discharge needle. A switching box designed either manual or programmable modes permit rapid between without changing sources, probes, breaking vacuum. can be operated using following techniques: ESI only, APCI ESI/APCI simultaneously, alternatingly. optimum operating conditions these were similar manufacturer’s original specifications except that flow rate lower (∼50 µL/min versus 1000 µL/min) externally heated nebulizing gas found desirable. four-component mixture, introduced injection, used demonstrate versatility of source.