Study on properties of wooden capillary electrospray ionization mass spectrometry

Rationale In view of the unique properties of wooden materials as electrospray emitters, a novel wooden capillary electrospray ionization (WC‐ESI) device was fabricated. The performance of a wooden capillary as an electrospray emitter was investigated by using a wooden capillary instead of the metal emitter of commercial ESI sources. Methods The mass spectrometric measurement of baicalein, emodin and myoglobin was carried out by using wooden capillary (WC) and metal capillary (MC) ESI sources. Contrasting analysis of signal intensity between WC and MC electrospray ionization mass spectrometry (ESI‐MS) was implemented at different sample flow rates. The effect of WC‐ESI‐MS and MC‐ESI‐MS was evaluated experimentally with electrospray solutions in different solvent ratios. Results Generally, the signal generated by WC‐ESI‐MS was much stronger than that obtained by MC‐ESI‐MS. In particular, the MS signal in negative ion mode was very strong, which may solve the long‐standing problem of low MS signals in negative ion mode, and fully improve the detection efficiency of ESI‐MS. Conclusions The signal intensity produced by WC‐ESI‐MS is significantly higher than that from MC‐ESI‐MS, and polymerization and electrolysis are reduced; therefore, the spectra become simpler. In addition, it is also tolerant to high flow rates and high aqueous phase samples.