Skip to Content

Molecular ionization from carbon nanotube paper.

Molecular ionization from carbon nanotube paper.

Angewandte Chemie (International ed. in English) (2014-03-20)

Rahul Narayanan, Depanjan Sarkar, R Graham Cooks, Thalappil Pradeep

ABSTRACT

Ambient ionization is achieved by spraying from a carbon nanotube (CNT)-impregnated paper surface under the influence of small voltages (≥3 V). Organic molecules give simple high-quality mass spectra without fragmentation in the positive or negative ion modes. Conventional field ionization is ruled out, and it appears that field emission of microdroplets occurs. Microscopic examination of the CNT paper confirms that the nanoscale features at the paper surface are responsible for the high electric fields. Raman spectra imply substantial current flows in the nanotubes. The performance of this analytical method was demonstrated for a range of volatile and nonvolatile compounds and a variety of matrices.

MATERIALS

Product Number

Brand

Product Description

Supelco

Methanol, Pharmaceutical Secondary Standard; Certified Reference Material

Sigma-Aldrich

Methanol, Absolute - Acetone free

Sigma-Aldrich

Methanol, ACS reagent, ≥99.8%

Sigma-Aldrich

Methanol, ACS reagent, ≥99.8%

Sigma-Aldrich

Methanol, ACS reagent, ≥99.8%

Sigma-Aldrich

Methanol, puriss., meets analytical specification of Ph Eur, ≥99.7% (GC)

Sigma-Aldrich

Methanol, BioReagent, ≥99.93%

Sigma-Aldrich

Methanol, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.8% (GC)

Sigma-Aldrich

Methanol, ACS spectrophotometric grade, ≥99.9%

Sigma-Aldrich

Methanol, Laboratory Reagent, ≥99.6%

Sigma-Aldrich

Methanol, HPLC Plus, ≥99.9%

Sigma-Aldrich

Methanol, suitable for HPLC, gradient grade, ≥99.9%

Sigma-Aldrich

Methanol, suitable for HPLC, gradient grade, suitable as ACS-grade LC reagent, ≥99.9%

Sigma-Aldrich

Methanol, suitable for HPLC, ≥99.9%

Supelco

Carbofuran, PESTANAL^®, analytical standard

Sigma-Aldrich

Methanol, NMR reference standard

Sigma-Aldrich

Triethylamine, purum, ≥99% (GC)

Sigma-Aldrich

Diphenylamine, puriss. p.a., redox indicator, ACS reagent, reag. Ph. Eur., ≥98% (GC)

Supelco

Diphenylamine, PESTANAL^®, analytical standard

Supelco

Methanol, analytical standard

Sigma-Aldrich

Carbofuran, 98%

Sigma-Aldrich

Tributylphosphine, mixture of isomers, 97%

Sigma-Aldrich

Methanol, anhydrous, 99.8%

Sigma-Aldrich

Diphenylamine, ACS reagent, ≥99%

Sigma-Aldrich

Triethylamine, for protein sequence analysis, ampule, ≥99.5% (GC)

Sigma-Aldrich

Tributylphosphine, ≥93.5% (Tri-N-butylphosphine, GC)

Sigma-Aldrich

Triethylamine, for amino acid analysis, ≥99.5% (GC)

Supelco

Parathion, PESTANAL^®, analytical standard

Sigma-Aldrich

Triethylamine, BioUltra, ≥99.5% (GC)

Sigma-Aldrich

Triethylamine, ≥99.5%