High production of small organic dicarboxylate dianions by DESI and ESI.

High production of small organic dicarboxylate dianions by DESI and ESI.

Journal of the American Society for Mass Spectrometry (2015-01-18)

Yonghui Dong, Graziano Guella, Fulvio Mattivi, Pietro Franceschi

ABSTRACT

A significant production of gas-phase dicarboxylate dianions has been observed in standard ESI and DESI during the analysis of small organic dicarboxylic acids under moderate or highly alkaline conditions. In ESI, this can be attributed to an excess of hydroxyl ions (OH(-)) which favor the formation of an high amount of dianions in solution, contemporarily trapping the potential counter ions during the ESI process. The results obtained in DESI highlight the role of the surface in trapping the counter-ions during desorption process and determining the ultimate nature of the observed gas-phase ions.

MATERIALS

Product Number

Brand

Product Description

271004

Sigma-Aldrich

Acetonitrile, anhydrous, 99.8%

254274

Sigma-Aldrich

Lithium hydroxide monohydrate, 99.95% trace metals basis

609765

Sigma-Aldrich

Sodium hydroxide-¹⁶O solution, 20 wt. % in H₂¹⁶O, 99.9 atom % ¹⁶O

733466

Sigma-Aldrich

Acetonitrile, electronic grade, 99.999% trace metals basis

L4533

Sigma-Aldrich

Lithium hydroxide monohydrate, BioXtra, 98.5-101.5% (titration)

45983

Supelco

Acetonitrile, analytical standard

60377

Sigma-Aldrich

Potassium hydroxide, tested according to Ph. Eur.

62528

Sigma-Aldrich

Lithium hydroxide monohydrate, BioUltra, ≥99.0% (T)

PHR1551

Supelco

Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material

1601340

USP

Residual Solvent Class 2 - Acetonitrile, United States Pharmacopeia (USP) Reference Standard

34888

Sigma-Aldrich

Acetonitrile, for HPLC, for UV, ≥99.9% (GC)

34851

Sigma-Aldrich

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

34998

Sigma-Aldrich

Acetonitrile, HPLC Plus, ≥99.9%

34881

Sigma-Aldrich

Acetonitrile, suitable for HPLC-GC, ≥99.8% (GC)

439134

Sigma-Aldrich

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

30603

Sigma-Aldrich

Potassium hydroxide, pellets, reag. Ph. Eur., ≥85%

221473

Sigma-Aldrich

Potassium hydroxide, ACS reagent, ≥85%, pellets

911062

Sigma-Aldrich

Potassium hydroxide, free-flowing, Redi-Dri^™, ACS reagent, ≥85%, pellets

757551

Sigma-Aldrich

Potassium hydroxide, anhydrous, ≥99.95% trace metals basis

P5958

Sigma-Aldrich

Potassium hydroxide, BioXtra, ≥85% KOH basis

417661

Sigma-Aldrich

Potassium hydroxide solution, 45 wt. % in H₂O

360457

Sigma-Aldrich

Acetonitrile, ACS reagent, ≥99.5%

402974

Sigma-Aldrich

Lithium hydroxide monohydrate, ACS reagent, ≥98.0%

60370

Sigma-Aldrich

Potassium hydroxide, puriss. p.a., ≥86% (T), pellets

60004

Sigma-Aldrich

Acetonitrile, ≥99.5% (GC)

484016

Sigma-Aldrich

Potassium hydroxide, reagent grade, 90%, flakes

494445

Sigma-Aldrich

Acetonitrile, biotech. grade, ≥99.93%

306568

Sigma-Aldrich

Potassium hydroxide, semiconductor grade, pellets, 99.99% trace metals basis (Purity excludes sodium content.)

34442

Sigma-Aldrich

Acetonitrile, suitable for DNA synthesis, ≥99.9% (GC)

06005

Sigma-Aldrich

Potassium hydroxide, puriss., meets analytical specification of Ph. Eur., BP, 85-100.5%, pellets