Influence of Boric Acid on Electrospray Ionization Efficiency

Rebane, Riin; Herodes, Koit

doi:10.1255/ejms.1160

Cited by 6 publications

(2 citation statements)

References 9 publications

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“…However, with higher analytical sensitivity of MS-based metabolomics methods, the effect of BA on metabolites in urine was revealed by Roux et al [25], Xiao et al [34], and us. It may be that BA alters the ionization properties of the metabolites in LC-MS-based studies as shown by Rebane and Herodes [43] who reported significant changes in signal intensities in LC-ESI-MS after adding BA. The observed separation in the PCA score plot (Figure 1B) between the BA 22 °C 48 h and BA −20/4 °C samples in the No PABA group showed that BA presented limited preservative efficacy in urine stored at 22 °C for ≥48 h, while the separation between BA 40 °C and BA −20/4 °C samples (Figure 1A,B) showed that BA had no preservative efficacy at 40 °C.…”

Section: Discussionmentioning

confidence: 99%

Influence of Storage Conditions and Preservatives on Metabolite Fingerprints in Urine

Wang

Palma-Duran

et al. 2019

Metabolites

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Human urine, which is rich in metabolites, provides valuable approaches for biomarker measurement. Maintaining the stability of metabolites in urine is critical for accurate and reliable research results and subsequent interpretation. In this study, the effect of storage temperature (4, 22, and 40 °C), storage time (24 and 48 h), and use of preservatives (boric acid (BA), thymol) and para-aminobenzoic acid (PABA) on urinary metabolites in the pooled urine samples from 20 participants was systematically investigated using large-scale targeted liquid chromatography tandem mass spectrometry (LC-MS/MS)-based metabolomics. Statistical analysis of 158 reliably detected metabolites showed that metabolites in urine with no preservative remained stable at 4 °C for 24 and 48 h as well as at 22 °C for 24 h, but significant metabolite differences were observed in urine stored at 22 °C for 48 h and at 40 °C. The mere addition of BA caused metabolite changes. Thymol was observed to be effective in maintaining metabolite stability in urine in all the conditions designed, most likely due to the inhibitory effect of thymol on urine microbiota. Our results provide valuable urine preservation guidance during sample storage, which is essential for obtaining reliable, accurate, and reproducible analytical results from urine samples.

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Section: Discussionmentioning

confidence: 99%

Influence of Storage Conditions and Preservatives on Metabolite Fingerprints in Urine

Wang

Palma-Duran

et al. 2019

Metabolites

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“…Although IE in ESI/MS has been thoroughly researched throughout the last decade, none of the studies focus on the IE of derivatized compounds. There have been some preliminary studies relating to IE of the derivatized compounds, but these results are not linked to the results of existing IE scales. In order to get better knowledge of the IEs of the derivatized compounds and to widen the scope of the existing IE scale, this work is focused on measuring derivatized amino acids and biogenic amines and anchoring these results to the previously developed IE scales …”

Section: Introductionmentioning

confidence: 99%

A systematic approach toward comparing electrospray ionization efficiencies of derivatized and non‐derivatized amino acids and biogenic amines

2018

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Ionization efficiency (IE) in mass spectrometry (MS) has been studied for many different compounds, and different IE scales have been constructed in order to quantitatively characterize IE. In the case of MS, derivatization has been used to increase the sensitivity of the method and to lower the limits of detection. However, the influence of derivatization on IE across different compounds and different derivatization reagents has not been thoroughly researched, so that practitioners do not have information on the IE-enhancing abilities of different derivatization reagents. Moreover, measuring IE via direct infusion of compounds cannot be considered fully adequate. Since derivatized compounds are in complex mixtures, a chromatographic method is needed to separate these compounds to minimize potential matrix effects. In this work, an IE measurement system with a chromatographic column was developed for mainly amino acids and some biogenic amines. IE measurements with liquid chromatography electrospray ionization mass spectrometry (LC/ESI/MS) were carried out, and IE scales were constructed with a calibration curve for compounds with and without derivatization reagent diethyl ethoxymethylenemalonate. Additionally, eluent composition effects on ionization were investigated. Results showed that derivatization increases IE for most of the compounds (by average 0.9 and up to 2-2.5 logIE units) and derivatized compounds have more similar logIE values than without derivatization. Mobile phase composition effects on ionization efficiencies were negligible. It was also noted that the use of chromatographic separation instead of flow injection mode slightly increases IE. In this work, for the first time, IE enhancement of derivatization reagents was quantified under real LC/ESI/MS conditions and obtained logIE values of derivatized compounds were linked with the existing scale.

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Development of amino acid derivatization reagents for liquid chromatography electrospray ionization mass spectrometric analysis and ionization efficiency measurements

Rebane

Rodima

Kütt

et al. 2015

Journal of Chromatography A

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Influence of Boric Acid on Electrospray Ionization Efficiency

Cited by 6 publications

References 9 publications

Influence of Storage Conditions and Preservatives on Metabolite Fingerprints in Urine

Influence of Storage Conditions and Preservatives on Metabolite Fingerprints in Urine

A systematic approach toward comparing electrospray ionization efficiencies of derivatized and non‐derivatized amino acids and biogenic amines

Development of amino acid derivatization reagents for liquid chromatography electrospray ionization mass spectrometric analysis and ionization efficiency measurements

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