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Quantitative analysis of polyhexamethylene guanidine (PHMG) oligomers via matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry with an ionic‐liquid matrix
Author(s) -
Yoon Donhee,
Lee Dongkun,
Lee JongHyeon,
Cha Sangwon,
Oh Han Bin
Publication year - 2014
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7096
Subject(s) - chemistry , mass spectrometry , ionic liquid , reproducibility , matrix (chemical analysis) , analytical chemistry (journal) , calibration curve , matrix assisted laser desorption/ionization , desorption , time of flight mass spectrometry , sample preparation , standard addition , chromatography , ionic bonding , ionization , detection limit , ion , organic chemistry , adsorption , catalysis
RATIONALE Quantifying polymers by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) with a conventional crystalline matrix generally suffers from poor sample‐to‐sample or shot‐to‐shot reproducibility. An ionic‐liquid matrix has been demonstrated to mitigate these reproducibility issues by providing a homogeneous sample surface, which is useful for quantifying polymers. In the present study, we evaluated the use of an ionic liquid matrix, i.e., 1‐methylimidazolium α‐cyano‐4‐hydroxycinnamate (1‐MeIm‐CHCA), to quantify polyhexamethylene guanidine (PHMG) samples that impose a critical health hazard when inhaled in the form of droplets. METHODS MALDI‐TOF mass spectra were acquired for PHMG oligomers using a variety of ionic‐liquid matrices including 1‐MeIm‐CHCA. Calibration curves were constructed by plotting the sum of the PHMG oligomer peak areas versus PHMG sample concentration with a variety of peptide internal standards. RESULTS Compared with the conventional crystalline matrix, the 1‐MeIm‐CHCA ionic‐liquid matrix had much better reproducibility (lower standard deviations). Furthermore, by using an internal peptide standard, good linear calibration plots could be obtained over a range of PMHG concentrations of at least 4 orders of magnitude. CONCLUSIONS This study successfully demonstrated that PHMG samples can be quantitatively characterized by MALDI‐TOFMS with an ionic‐liquid matrix and an internal standard. Copyright © 2014 John Wiley & Sons, Ltd.