Octadecyl pipette tip coupled to electrospray ionization mass spectrometry

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The availability of easy to handle interfaces for the direct analysis of samples by mass spectrometry is highly desirable as it clearly simplifies the analytical measurement process. Moreover, the reduction of errors in the final result given can be highlighted as a great advantage. These interfaces must reduce the amount of interferents that can eventually reach the detector while providing a reproducible and quantitative response.

Researchers from the University of Hong Kong developed a pipette-tip-ESI-MS technique for the direct analysis of solid samples. The interface coupled a pipette-tip with a syringe and a syringe pump (1). Now they have evolved this interface to the microextraction context by replacing the empty pipette tip by a new one filled with conventional reverse-phase C18 sorbent (2). In this way, after retention, the analytes are directly sprayed out for the ESI-MS analysis by applying a high voltage to the syringe needle (see the diagram in this picture free available in the Journal webpage). The so-called pipette-tip based microextraction has been favorably evaluated for the analysis of protein solutions containing salts and detergents as well as the quantitation of ketamine and norketamine in urine.

Those of you who are familiar with the analysis of proteins solutions are aware about the incompatibility of such matrices with the direct infusion MS analysis. The present approach has been favorably evaluated for such bioanalytical process, so you will find the reading of this contribution in the microextraction context attractive.

Our readers more interested in the quantitative information will also find this information useful to simplify the sample treatment.

From Microextraction Tech, we are sure that all our followers will enjoy with the reading of this contribution.

References
(1) Direct analysis of herbal powders by pipette-tip electrospray ionization mass spectrometry. Link to the article

(2) Rapid analysis of raw solution samples by C18 pipette-tip electrospray ionization mass spectrometry. Link to the article

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