CN-122016985-A - Screening method and application of novel p-phenylenediamine compounds in atmosphere

CN122016985ACN 122016985 ACN122016985 ACN 122016985ACN-122016985-A

Abstract

The invention discloses a screening method and application of a novel p-phenylenediamine compound in the atmosphere, wherein the screening method comprises screening characteristic fragment ions based on the known p-phenylenediamine compound, performing targeted screening, retaining parent ions with mass-to-charge ratio of below 500 Da and signal intensity higher than 5 x 10 4 cps, retaining candidate parent ions pointed by two or more different characteristic fragment ions at the same time, and determining molecular formula through targeted identification and neutral loss analysis. The method is based on the principle that p-phenylenediamine compounds can generate cracking reflecting the characteristics of the diphenylamine core in a mass spectrum due to a common parent nucleus structure, establishes a 'cracking fingerprint' of the p-phenylenediamine compounds, captures all compounds capable of generating fragments with the same characteristics by utilizing precursor ion scanning, and reversely deduces the difference part of the screened candidate compounds with the known structure core through neutral loss analysis and targeted identification to efficiently screen out unknown compounds with the structure highly similar to the known p-phenylenediamine substances.

Inventors

JIANG NAN
YUAN HANG
LI MINZHEN
REN YIWEN
YANG YONGKE
Guo Jiasen
WANG ZICHEN
WANG NA

Assignees

郑州大学

Dates

Publication Date: 20260512
Application Date: 20260126

Claims (6)

1. A method for screening novel p-phenylenediamine compounds in the atmosphere is characterized by comprising the following steps of The method comprises the steps of firstly, carrying out fragment analysis on known p-phenylenediamine compounds, screening out at least one group of characteristic fragment ions with structure, and determining a chemical formula corresponding to the characteristic fragment ions, wherein the known p-phenylenediamine compounds comprise IPPD, CPPD, DPPD, DNPD, 6PPD and 6PPD-Q; Secondly, determining the liquid condition of the known p-phenylenediamine compound in the first step; Thirdly, performing quasi-targeting screening on the atmospheric sample based on the characteristic fragment ions screened in the first step and the chromatographic conditions and mass spectrum parameters determined in the precursor ion scanning mode and the second step, and reserving parent ions with mass-to-charge ratio of below 500 Da and signal intensity higher than 5 multiplied by 10 4 cps; Fourthly, performing neutral loss analysis based on the candidate parent ions obtained in the third step and the characteristic fragment ions obtained by screening in the first step, retaining the candidate parent ions pointed by two or more different characteristic fragment ions at the same time, wherein the neutral loss quality difference is at least matched with the theoretical quality number of one neutral small molecule; And fifthly, carrying out targeted identification on the atmospheric sample under the multi-reaction monitoring mode and the chromatographic conditions and the mass spectrum parameters determined in the second step, obtaining the chromatographic peak of each candidate parent ion in the fourth step, determining the type of the candidate parent ion based on the poor neutral loss quality, the mass number of the parent ion and the retention time, and deducing to obtain the molecular formula.
2. The method for screening of novel p-phenylenediamine compounds in the atmosphere according to claim 1, wherein in said first step, fragment ion mass spectrometry is performed on the known p-phenylenediamine compounds by HR-MS, and the collision energy is sequentially increased in steps of 5v starting from the collision energy.
3. The method for screening the novel p-phenylenediamine compounds in the atmosphere according to claim 1, wherein the chromatographic conditions of the liquid condition in the second step are as follows, mobile phase A is 0.1% of formic acid water, mobile phase B is acetonitrile, the flow rate is 0.3 ml/min, the sample injection amount is 10 mu L, the mobile phase adopts gradient elution, namely 0-2 min,10% B, 2-25 min,10-90% B, 25-28 min,90% B, 28-30 min and 10% B; The mass spectrum parameters are that the ion source temperature is 500 ℃, the ion spraying voltage is 5500 V,Gas 1,Gas 2, the Curtain gas is 50,50 and 35 psi respectively, and the sample injection speed is 3.0 mu L/min.
4. The method for screening the novel p-phenylenediamine compounds in the atmosphere according to claim 1, wherein in the third step, the atmospheric sample is obtained by sampling with a PM 2.5 sampling film, cutting the PM 2.5 sampling film into strips, placing the strips into a centrifuge tube, sequentially extracting with n-hexane, acetone and n-hexane/acetone by ultrasound, centrifuging the extracting solution to remove impurities, drying the supernatant by a nitrogen blowing instrument, and sequentially re-dissolving, concentrating and filtering by using acetonitrile.
5. The method for screening a novel p-phenylenediamine compound in the atmosphere according to claim 1, wherein in the third step, when the quasi-targeting screening is performed in the precursor ion scanning mode, the mass-to-charge ratio range is set to 150-1000 Da, the collision energy is increased to 50v in steps of 5v, and the scanning rate is 1000 Da/s.
6. The use of the screening method of any one of claims 1-5 in constructing a novel p-phenylenediamine information library, wherein the information library comprises characteristic fragment ions, parent ion mass to charge ratios, retention times, and inferred molecular formulas for the novel p-phenylenediamine.

Description

Screening method and application of novel p-phenylenediamine compounds in atmosphere Technical Field The invention relates to the field of screening of novel pollutants in the atmosphere, in particular to a method for screening novel p-phenylenediamine compounds in the atmosphere and application thereof. Background P-phenylenediamine compounds (p-PHENYLENEDIAMINES, PPDs) are para-phenylene ring compounds containing two amino substituents and are widely used in industry and consumer products, such as dyeing wool, fur and hair, photographic contrast agents, rubber antioxidants (especially 6PPD and IPPD), and the like. However, phenylenediamine compounds (e.g., p-phenylenediamine, m-phenylenediamine, etc.) are a potentially health-hazardous chemical, PPDs and their degradation products are of a wide variety and there are many unknown compounds and degradation products may be more toxic. In view of its serious ecological hazards and potential health risks, as well as the current lack of knowledge of potential PPDs analogs, it is critical to build a comprehensive analytical data profile by screening the environment for novel PPD-type compounds. At present, novel phenylenediamine compounds (such as degradation products of phenylenediamine compounds) cannot be screened specifically by commercial standard substances. The non-targeted analysis technique (Untargeted Analysis) aims at unbiased comprehensive detection and data acquisition of small molecule compounds in a sample, and has the advantage of widely covering compound information, but the subsequent compound identification link generally faces a great challenge. In contrast, precursor ion scanning (Precursor Ion Scanning) is a directed screening strategy based on specific structural features. The technology can efficiently and specifically screen all precursor ions capable of generating fragments from complex mass spectrum data by fixedly monitoring a characteristic product ion (such as common functional group fragments of a certain type of compound), thereby realizing rapid classification and identification of metabolites (such as a certain lipid or a specific modified metabolite) of a parent nucleus with a common structure. However, it is important how to combine non-targeted analysis techniques with precursor ion scanning to enhance specific detection of target substances. In addition, no report on a specific screening method of the novel phenylenediamine compound has been presented, so that the current knowledge of the type of the novel phenylenediamine compound and the limitation thereof are made. Disclosure of Invention In view of the above, the invention provides a screening method for novel p-phenylenediamine compounds in the atmosphere, and the invention also provides application of the screening method. In order to achieve the above purpose, the invention adopts the following technical scheme: the invention provides a method for screening novel p-phenylenediamine compounds in the atmosphere, which comprises the following steps of The method comprises the steps of firstly, carrying out fragment analysis on known p-phenylenediamine compounds, screening out at least one group of characteristic fragment ions with structure, and determining a chemical formula corresponding to the characteristic fragment ions, wherein the known p-phenylenediamine compounds comprise IPPD, CPPD, DPPD, DNPD, 6PPD and 6PPD-Q; Secondly, determining the liquid condition of the known p-phenylenediamine compound in the first step; Thirdly, performing quasi-targeting screening on the atmospheric sample based on the characteristic fragment ions screened in the first step and the chromatographic conditions and mass spectrum parameters determined in the precursor ion scanning mode and the second step, and reserving parent ions with mass-to-charge ratio of below 500 Da and signal intensity higher than 5 multiplied by 10 4 cps; Fourthly, performing neutral loss analysis based on the candidate parent ions obtained in the third step and the characteristic fragment ions obtained by screening in the first step, retaining the candidate parent ions pointed by two or more different characteristic fragment ions at the same time, wherein the neutral loss quality difference is at least matched with the theoretical quality number of one neutral small molecule; And fifthly, carrying out targeted identification on the atmospheric sample under the multi-reaction monitoring mode and the chromatographic conditions and the mass spectrum parameters determined in the second step, obtaining the chromatographic peak of each candidate parent ion in the fourth step, determining the type of the candidate parent ion based on the poor neutral loss quality, the mass number of the parent ion and the retention time, and deducing to obtain the molecular formula. The method has the advantages that based on the principle that p-phenylenediamine compounds can generate cracking reflecting the characteristics of the p-p