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Automatic sampling and analysis of organics and biomolecules by capillary action-supported contactless atmospheric pressure ionization mass spectrometry.

Hsieh CH, Meher AK, Chen YC - PLoS ONE (2013)

Bottom Line: Furthermore, the well containing the rinsing solvent is alternately arranged between the sample wells.No carryover problems are observed during the analyses.The feasibility of using this setup for quantitative analysis is also demonstrated.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan.

ABSTRACT
Contactless atmospheric pressure ionization (C-API) method has been recently developed for mass spectrometric analysis. A tapered capillary is used as both the sampling tube and spray emitter in C-API. No electric contact is required on the capillary tip during C-API mass spectrometric analysis. The simple design of the ionization method enables the automation of the C-API sampling system. In this study, we propose an automatic C-API sampling system consisting of a capillary (∼1 cm), an aluminium sample holder, and a movable XY stage for the mass spectrometric analysis of organics and biomolecules. The aluminium sample holder is controlled by the movable XY stage. The outlet of the C-API capillary is placed in front of the orifice of a mass spectrometer, whereas the sample well on the sample holder is moved underneath the capillary inlet. The sample droplet on the well can be readily infused into the C-API capillary through capillary action. When the sample solution reaches the capillary outlet, the sample spray is readily formed in the proximity of the mass spectrometer applied with a high electric field. The gas phase ions generated from the spray can be readily monitored by the mass spectrometer. We demonstrate that six samples can be analyzed in sequence within 3.5 min using this automatic C-API MS setup. Furthermore, the well containing the rinsing solvent is alternately arranged between the sample wells. Therefore, the C-API capillary could be readily flushed between runs. No carryover problems are observed during the analyses. The sample volume required for the C-API MS analysis is minimal, with less than 1 nL of the sample solution being sufficient for analysis. The feasibility of using this setup for quantitative analysis is also demonstrated.

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Related in: MedlinePlus

Calibration curve.(A) Representative EIC plots of the ions at m/z 175 (protonated arginine) and m/z 166 (protonated phenylalanine) obtained from a series of samples containing various arginine concentrations (1, 4, 6, and 10 µM) and phenylalanine (1 µM) as the internal standard for autosampling C-API MS analysis. Capillary flushing was conducted on every other well using acetonitrile/deionized water (1∶1, v/v) as the rinse solvent. (B) Plot obtained from the peak area ratio at m/z 175 to that at m/z 166 versus the arginine concentration as obtained from panel A. The results were obtained from three replicates using the same capillary as the sampling tube and C-API emitter.
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pone-0066292-g005: Calibration curve.(A) Representative EIC plots of the ions at m/z 175 (protonated arginine) and m/z 166 (protonated phenylalanine) obtained from a series of samples containing various arginine concentrations (1, 4, 6, and 10 µM) and phenylalanine (1 µM) as the internal standard for autosampling C-API MS analysis. Capillary flushing was conducted on every other well using acetonitrile/deionized water (1∶1, v/v) as the rinse solvent. (B) Plot obtained from the peak area ratio at m/z 175 to that at m/z 166 versus the arginine concentration as obtained from panel A. The results were obtained from three replicates using the same capillary as the sampling tube and C-API emitter.

Mentions: The feasibility of using the C-API autosampling system for quantitative analysis was examined further. The aluminium plate was loaded with different arginine concentrations (1, 4, 6, and 10 µM), whereas phenylalanine (1 µM) was used as the internal standard. The rinse solvent (acetonitrile/deionized water (1∶1, v/v)) was placed in every other well next to the sample wells. Figure 5A shows the representative EIC plots at m/z 175 and 166. The peak area at m/z 175 increased as the arginine concentration in the sample increased. The peak area of the internal standard at m/z 166 did not change much. Figure 5B shows the plot of the ratio of the peak area at m/z 175 to that at m/z 166 versus the arginine concentration with an acceptable linear regression coefficient. The results demonstrated that the possibility of using the C-API auto-sampling system approach for quantitative analysis.


Automatic sampling and analysis of organics and biomolecules by capillary action-supported contactless atmospheric pressure ionization mass spectrometry.

Hsieh CH, Meher AK, Chen YC - PLoS ONE (2013)

Calibration curve.(A) Representative EIC plots of the ions at m/z 175 (protonated arginine) and m/z 166 (protonated phenylalanine) obtained from a series of samples containing various arginine concentrations (1, 4, 6, and 10 µM) and phenylalanine (1 µM) as the internal standard for autosampling C-API MS analysis. Capillary flushing was conducted on every other well using acetonitrile/deionized water (1∶1, v/v) as the rinse solvent. (B) Plot obtained from the peak area ratio at m/z 175 to that at m/z 166 versus the arginine concentration as obtained from panel A. The results were obtained from three replicates using the same capillary as the sampling tube and C-API emitter.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3675195&req=5

pone-0066292-g005: Calibration curve.(A) Representative EIC plots of the ions at m/z 175 (protonated arginine) and m/z 166 (protonated phenylalanine) obtained from a series of samples containing various arginine concentrations (1, 4, 6, and 10 µM) and phenylalanine (1 µM) as the internal standard for autosampling C-API MS analysis. Capillary flushing was conducted on every other well using acetonitrile/deionized water (1∶1, v/v) as the rinse solvent. (B) Plot obtained from the peak area ratio at m/z 175 to that at m/z 166 versus the arginine concentration as obtained from panel A. The results were obtained from three replicates using the same capillary as the sampling tube and C-API emitter.
Mentions: The feasibility of using the C-API autosampling system for quantitative analysis was examined further. The aluminium plate was loaded with different arginine concentrations (1, 4, 6, and 10 µM), whereas phenylalanine (1 µM) was used as the internal standard. The rinse solvent (acetonitrile/deionized water (1∶1, v/v)) was placed in every other well next to the sample wells. Figure 5A shows the representative EIC plots at m/z 175 and 166. The peak area at m/z 175 increased as the arginine concentration in the sample increased. The peak area of the internal standard at m/z 166 did not change much. Figure 5B shows the plot of the ratio of the peak area at m/z 175 to that at m/z 166 versus the arginine concentration with an acceptable linear regression coefficient. The results demonstrated that the possibility of using the C-API auto-sampling system approach for quantitative analysis.

Bottom Line: Furthermore, the well containing the rinsing solvent is alternately arranged between the sample wells.No carryover problems are observed during the analyses.The feasibility of using this setup for quantitative analysis is also demonstrated.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan.

ABSTRACT
Contactless atmospheric pressure ionization (C-API) method has been recently developed for mass spectrometric analysis. A tapered capillary is used as both the sampling tube and spray emitter in C-API. No electric contact is required on the capillary tip during C-API mass spectrometric analysis. The simple design of the ionization method enables the automation of the C-API sampling system. In this study, we propose an automatic C-API sampling system consisting of a capillary (∼1 cm), an aluminium sample holder, and a movable XY stage for the mass spectrometric analysis of organics and biomolecules. The aluminium sample holder is controlled by the movable XY stage. The outlet of the C-API capillary is placed in front of the orifice of a mass spectrometer, whereas the sample well on the sample holder is moved underneath the capillary inlet. The sample droplet on the well can be readily infused into the C-API capillary through capillary action. When the sample solution reaches the capillary outlet, the sample spray is readily formed in the proximity of the mass spectrometer applied with a high electric field. The gas phase ions generated from the spray can be readily monitored by the mass spectrometer. We demonstrate that six samples can be analyzed in sequence within 3.5 min using this automatic C-API MS setup. Furthermore, the well containing the rinsing solvent is alternately arranged between the sample wells. Therefore, the C-API capillary could be readily flushed between runs. No carryover problems are observed during the analyses. The sample volume required for the C-API MS analysis is minimal, with less than 1 nL of the sample solution being sufficient for analysis. The feasibility of using this setup for quantitative analysis is also demonstrated.

Show MeSH
Related in: MedlinePlus