Direct analysis of very small amount of blood by a disposable monolithic column mass spectrometry kit

Abstract

A disposable monolithic column mass spectrometry kit was developed based on monolithic column for microsampling, purification, storage, transportation and direct MS analysis of whole blood. The kit mainly consists of a capillary for quantitative microsampling of very small amount of blood (2 μL), a cation exchange monolithic column for purification and storage, and a syringe for loading sample. The cost of the kit is estimated to only one dollar. This MS kit is very friendly to various users that one can easily siphon small amount blood in the kit followed by rapid sample clean-up in 30s. We established a rapid quantitative method using the kit with a limit detection as low as 0.33 nM, achieved more than five orders of magnitude enhancement in MS analysis sensitivity compared to nanoelectrospray ionization MS analysis. The kit can avoid analyte exposure to oxygen, moisture and sunlight, which helps the storage of the sample. The relative standard deviation within 10 days were less than 10%. This method has been successfully applied to the quantitative analysis of procainamide hydrochloride in 2 μL rat blood. These results indicate that this kit does have the potential to achieve low-cost, highly sensitive quantitative MS analysis of biological sample.