Nano-spray-fticr-ms analysis method and device for dissolved organic matter in environmental solid samples

Abstract

The invention discloses a nano-spray-FTICR-MS analysis method and device for dissolving organic matter in an environmental solid sample, comprising a nano-spray device and a Fourier transform ion cyclotron resonance mass spectrometer; the nano-spray device includes a glass nozzle, a conductive needle, an adapter Rubber head, double pressurized ball and gas storage bag, the sample solution loaded on the glass nozzle is a mixed solution composed of interstitial water and organic solvent, and the nozzle is aligned with the injection port of the Fourier transform ion cyclotron resonance mass spectrometer. The present invention uses a nanoliter spray device coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), does not purify and enrich samples by solid phase extraction, but improves ionization efficiency and reduces Ion selective suppression can realize the direct analysis of interstitial water in environmental solid samples, and solve the key problems of the current technology that need to lose the signal of biologically active molecules through the pretreatment of solid phase extraction and the selective signal suppression of common electrospray sources.

Description

technical field [0001] The invention relates to the technical field of natural dissolved organic matter (DOM) analysis, in particular to an analysis method and device shared by nanoliter spray and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Background technique [0002] Soil and sediments are the largest carbon pools in the earth's terrestrial system. Most of the carbon is encapsulated in minerals or exists in the solid phase after long-term mineralization and stabilization. The solid phase contains a small amount of interstitial water, and the dissolved organic matter has Highly active, it plays a key role in the formation of soil and sediment aggregates, carbon storage, and global carbon cycle. It is also a source of microbial energy and plant nutrients nitrogen and phosphorus. In addition, due to the high mobility and diversity of dissolved organic matter, studies have confirmed that it also plays a key role in the transport of metal ions and o...

AI Technical Summary

Problems solved by technology

[0004] (1) The current general pretreatment method is to extract organic matter through PPL column (Thorsten Dittmar, BorisKoch, Norbert Hertkorn, and Gerhard Kattner, A Simple and Efficient Method for the Solid-Phase Extraction of Dissolved Organic Matter (SPE-DOM) from Seawater, Limnology and Oceanography, 6(2008), 230–35), since there may be as many as 100,000 kinds of dissolved organic matter, including polypeptides, sugars, and amorphous polymer humic acid whose structure cannot be confirmed, etc., before column extraction The processing method leads to the selective loss of characteristic organic matter signal (Raeke Julia, Lechtenfeld Oliver J, Wagner Martin, et al. Selectivity of solid phase extraction of freshwater dissolved organic matter and its effect on ultrahigh resolution mass spectrum. Environmental Science Processes & Impacts, 2016, 18(7): 918-27.), especially biologically derived and bioavailable molecules, as well as black carbon, lipids, polyphenols, etc. These lost signals are important for understanding the biogeochemical processes of dissolved organic matter, and they represent Components that may be utilized by soil organisms, may be converted into nutrients, and may affect the retention and migration of pollutants in the soil

Depending on the source of the sample, the extraction loss is about 10%-90% (Yan Li, Mourad Harir, Jenny Uhl, Basem Kanawati, Marianna Lucio, Kirill S.Smirnov, et al., How Representative Are Dissolved Organic Matter (DOM) Extracts? A ComprehensiveStudy of Sorbent Selectivity for DOM Isolation, Water Research, 116(2017), 316–23), may be as high as 90% extraction loss also weakens the quantitative significance of the method, and the difference between different samples is reduced due to the same extraction selectivity

[0005] (2) After the pretreatment is completed, the current international mass spectrometry detection method is to ionize through the general electrospray source and then enter the Fourier transform ion cyclotron resonance mass spectrometry detection. However, due to the obvious selective suppression problem of the electrospray source, this Method For strong polar compounds with low surface activity, they may be inhibited by substances with high surface activity during the ionization process, especially those containing amino acids or sugars, the ionization efficiency of substances with strong polarity is significantly lower than that with surface activity active substance

[0006] (3) In addition, the water sample required for the analysis of natural dissolved organic matter by solid-phase extraction is generally greater than 20mL, which is very difficult to sample in this soil, so the traditional method is to obtain dissolved organic matter by adding ultrapure water or water with added inorganic salts for elution , but this method cannot represent the dissolved organic matter in the actual soil, but only the potentially leached substances, and the actual eluted dissolved organic matter is related to the elution method, the amount of added water and inorganic salts, resulting in the results of the same sample Uncertain

[0007] To sum up the above three points, there are three technical problems that need to be solved urgently in the existing methods and technologies: loss of pre-processing signal, ionization suppression in the detection process, and limitation of sample collection volume

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