title: Interfacing microsampling droplets and mass spectrometry by paper spray ionization for online chemical monitoring of cell culture.
abstract: In this work, the establishment of a microdialysis-paper spray ionization-mass spectrometry (MS) system was described. A homemade microdialysis module was employed for sampling, and microdroplets were generated at the outlet of the capillary conducting the dialysate. Online MS analysis of each microdroplet was immediately accomplished, interfacing by paper spray ionization. Analytical performance of the method was investigated and improved through the introduction of thinner capillary tubes and the optimization of spray solvent and paper substrate. For microdroplets with concentrated salt at 50 nL, the limit of detection at 0.8 ppm (or 40 pg absolute) and a highest resolution at about 1.5 s were achieved. The integrated system was applied into the online monitoring of glucose concentration in cell culture mediums. A satisfactory linearity of the calibration curve between the relative MS intensity and the glucose concentration was observed. Furthermore, as a model, hormone regulation of the glucose concentration was investigated. This work demonstrated the potential application of the label-free, online "MS sensor" into studies on cellular metabolism.
authors.affiliation: Beijing Key Laboratory of Microanalytical Methods and Instrumentation, Department of Chemistry, Tsinghua University , Beijing 100084, People's Republic of China.
authors.forename: Wu
authors.initials: W
authors.lastname: Liu
authors.forename: Niejun
authors.initials: N
authors.lastname: Wang
authors.forename: Xuexia
authors.initials: X
authors.lastname: Lin
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ma
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D003470:Culture Media / Q000032:analysis* / Q000737:chemistry; D004837:Epinephrine / Q000494:pharmacology; D004867:Equipment Design; D005947:Glucose / Q000032:analysis; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D020407:Internet; D057230:Limit of Detection; D017551:Microdialysis; D010209:Paper; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*; D055672:Static Electricity
chemical_list: D003470:Culture Media; D007328:Insulin; D005947:Glucose; D004837:Epinephrine