Metal salt assisted electrospray ionization mass spectrometry for the soft ionization of GAP polymers in negative ion mode

Abstract

A soft metal salt assisted electrospray ionization mass spectrometry has been developed to characterize directly GAP polymers through the complexing effect of anions from metal salts with glycidyl azide polymers (GAP) in a negative ion mode.

Progress on the development of a metal salt-assisted ionization source for the mass spectrometric analysis of polymers

“…According to the literature, a variety of cations have been widely used for the analysis of different types of polymers and the formation of [M + cation] n+ adducts (Na + , Ag + , K + , Cu 2+ , Cs + , Cr 3+ ) have been observed, while the anions applied to induce the so ionization of these particular polymers, the [M + anion] nÀ adducts (anion ¼ NO 3 À , Cl À , I À , SO 4 2À and Br À ) have been formed. 115,[122][123][124][125][126] Furthermore, metal salts are available at low cost and could easily be found in chemistry laboratories, making them useful for assisting the ionization system, which, would be a much more practical and economical choice. [60][61][62] Metal salts-based developed strategies would provide a promising platform for MS techniques in polymer characterization.…”

“…In 2015, Jianga et al 114 addressed these issues (limitations) by replacing the paper platform with a glass microscope slide to monitor in real-time Cp 2 ZrCl 2 /MAO homogeneously catalyzed polymerization of ethylene and to induce droplet spray ionization. A novel method based on paper spray mass spectrometry (PS-MS) has been developed by our research group 115 to analyze glycidyl azide polymers (GAP) with the involvement of metal salts in the spray solvent. The efficient and so ionization of GAP samples was achieved by doping metal salts, such as NaNO 3 , into GAP solution during analysis.…”

“…As [GAP + Cl] À and Cl À were involved in the spray plume, the bound Cl À in the structure of [GAP + Cl] À adducts could partially shielded the electric eld-induced force applied to the GAP structure. 115 As a result, a soer ionization event occurred when NaCl was added to the GAP solution compared to that without NaCl. It should be mentioned that this method could not allow producing intact GAP species in the gas phase.…”

“…In this regard, this so ionization source has been proved to have some applications in elucidating polymer structures. 115 For example, it has been shown that complexing interactions between GAP and NO 3 À could allow the prevention of [GAP + NO 3 ] À fragmentation, and the role played by cations and anions from metal salts have great signicant effects on the performance of nanoelctrospray ionization mass spectrometry. In our group, we introduced metal salts such as NaNO 3 into the sample solution during nanoESI for the purpose of improving the so ionization of GAP samples.…”

Paper Spray Ionization Mass Spectrometry as a Potential Tool for Early Diagnosis of Cervical Cancer

“…When a high voltage is applied to the paper, a spray with charged droplets is generated at the paper tip and goes toward the mass spectrometer inlet for MS analysis . The analytical performance of PSI-MS has been evaluated in a wide range of applications, including the detection of drugs in fingerprint samples, quantifications of pesticides in fruits and vegetables, , characterization of energetic polymers, investigations of inks and questioned documents, analysis of drugs of abuse, , and coupling to portable mass spectrometers for on-site analysis . In addition, PSI-MS has been widely employed in clinical diagnosis, − because of its ability to allow biofluid analysis using a small amount of sample with minimal or even no sample preparation (for example, by applying few microliters of plasma, serum, or whole blood directly onto a triangular paper), which can significantly reduce the invasiveness to the patients and waiting time for clinical reports.…”