Method for detecting polycyclic aromatic hydrocarbon

Abstract

The invention relates to the technical field of mass spectrometry, in particular to a polycyclic aromatic hydrocarbon detection method. The polycyclic aromatic hydrocarbon detection method comprises the following steps: respectively preparing polycyclic aromatic hydrocarbon standard substance series solutions and a to-be-detected polycyclic aromatic hydrocarbon sample solution; the polycyclic aromatic hydrocarbon standard substance series solution comprises a plurality of polycyclic aromatic hydrocarbon standard substance solutions with different concentrations; the polycyclic aromatic hydrocarbon standard substance series solution and the to-be-detected polycyclic aromatic hydrocarbon sample solution comprise the same amount of internal standard and the same amount of derivative reagent; respectively ionizing the polycyclic aromatic hydrocarbon standard substance series solution and the polycyclic aromatic hydrocarbon sample solution to be detected through an electrochemistry-assisted electrospray method, and then carrying out mass spectrum detection; constructing a standard curve reflecting peak intensity and polycyclic aromatic hydrocarbon concentration according to the detection result of the polycyclic aromatic hydrocarbon standard substance series solution, and substituting the detection result of the to-be-detected polycyclic aromatic hydrocarbon sample solution into the standard curve to obtain the polycyclic aromatic hydrocarbon concentration in the to-be-detected polycyclic aromatic hydrocarbon sample solution.

Description

Technical Field

[0001] This application relates to the technical field of mass spectrometry analysis, and particularly relates to a method for detecting polycyclic aromatic hydrocarbons. Background Art

[0002] Polycyclic Aromatic Hydrocarbons (PAHs) are a class of non-polar compounds composed of multiple benzene rings. They widely exist in the environment and are produced through incomplete combustion or pyrolysis processes. When tobacco burns at high temperatures, it produces various PAHs, such as naphthalene, acenaphthene, fluorene, benzo[a]pyrene, etc. These substances pose potential hazards to human health. Therefore, developing an efficient method for detecting polycyclic aromatic hydrocarbons is crucial for evaluating and controlling the levels of polycyclic aromatic hydrocarbons in cigarette smoke.

[0003] Mass spectrometry (MS) and its related technologies are one of the most commonly used methods for detecting polycyclic aromatic hydrocarbons. Currently, the method mainly used for detecting polycyclic aromatic hydrocarbons is gas chromatography - mass spectrometry (GC-MS). The GC-MS method has advantages such as high sensitivity and accurate quantification. This method can separate and identify multiple specific polycyclic aromatic hydrocarbons in complex matrices, but this method requires a cumbersome sample preparation process, and it takes dozens of minutes to detect a single sample.

[0004] Direct mass spectrometry based on electrospray ionization (EIS) has the advantage of fast analysis speed. However, the common EIS method is usually used for polar compounds, and the non-polarity of polycyclic aromatic hydrocarbons makes it difficult to effectively ionize them under traditional ESI conditions, resulting in low detection sensitivity and unable to fully utilize the advantage of rapid analysis of ESI - mass spectrometry detection. Therefore, providing a detection method with high sensitivity, accurate quantification, and capable of quickly determining the content of polycyclic aromatic hydrocarbons plays an important role in real-time monitoring of polycyclic aromatic hydrocarbons. Summary of the Invention

[0005] Based on this, this application provides a method for detecting polycyclic aromatic hydrocarbons. The detection method provided by this application detects the sample solution of polycyclic aromatic hydrocarbons to be measured containing an internal standard and a derivatization reagent through an electrochemical-assisted electrospray method, and has the advantages of low detection limit, high sensitivity, and fast detection speed.

[0006] In the first aspect of this application, a method for detecting polycyclic aromatic hydrocarbons is provided, including the following steps:

[0007] Prepare a series of standard solutions of polycyclic aromatic hydrocarbons and a sample solution of polycyclic aromatic hydrocarbons to be measured respectively; wherein, the series of standard solutions of polycyclic aromatic hydrocarbons includes standard solutions of polycyclic aromatic hydrocarbons with multiple different concentrations; the series of standard solutions of polycyclic aromatic hydrocarbons and the sample solution of polycyclic aromatic hydrocarbons to be measured include the same amount of internal standard and the same amount of derivatization reagent;

[0008] After ionizing the polycyclic aromatic hydrocarbon standard series solution and the polycyclic aromatic hydrocarbon sample solution to be measured by electrochemically assisted electrospray ionization respectively, mass spectrometry detection is carried out;

[0009] According to the detection results of the polycyclic aromatic hydrocarbon standard series solution, a standard curve reflecting the peak intensity and the concentration of polycyclic aromatic hydrocarbons is constructed, and the detection results of the polycyclic aromatic hydrocarbon sample solution to be measured are substituted into the standard curve to obtain the concentration of polycyclic aromatic hydrocarbons in the polycyclic aromatic hydrocarbon sample solution to be measured.

[0010] In one embodiment, the polycyclic aromatic hydrocarbons include one or more of naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, and benzo[a]pyrene.

[0011] In one embodiment, the internal standard is the 13 C or deuterium isotope-labeled compound of the polycyclic aromatic hydrocarbon.

[0012] In one embodiment, the derivatization reagent includes one or more of the compounds having the structures shown in formulas (I) to (III):

[0013] , , ; wherein, R 11 , R 12 , R 13 are each independently H or a C1-C6 alkyl group; each time R2 appears, it is independently H, a hydroxyl group, a C1-C6 alkyl group or a C1-C6 alkoxy group; m is any integer from 1 to 5; each time R3 appears, it is independently H, a hydroxyl group, a C1-C6 alkyl group or a C1-C6 alkoxy group; n is any integer from 1 to 7.

[0014] In one embodiment, the parameters for mass spectrometry detection have one or more of the following characteristics:

[0015] (1) The ionization mode is positive ion mode;

[0016] (2) The mass spectrometry scanning mode is multiple reaction monitoring (MRM) mode;

[0017] (3) The curtain gas pressure is 8 psi to 15 psi;

[0018] (4) The exit potential of the collision cell is 8 volts to 15 volts;

[0019] (5) The heating temperature is 140 °C to 160 °C.

[0020] In one embodiment, the steps of constructing a standard curve reflecting the peak intensity and the concentration of polycyclic aromatic hydrocarbons according to the detection results of the polycyclic aromatic hydrocarbon standard series solution include:

[0021] Obtain the peak intensities of the polycyclic aromatic hydrocarbon-derivative reagent adducts and the peak intensities of the internal standard-derivative reagent adducts in the series of polycyclic aromatic hydrocarbon standard solutions respectively;

[0022] Using the ratio of the peak intensity of the polycyclic aromatic hydrocarbon-derivative reagent adduct to the peak intensity of the internal standard-derivative reagent adduct as the ordinate, and the ratio of the concentration of the polycyclic aromatic hydrocarbon in the series of polycyclic aromatic hydrocarbon standard solutions to the concentration of the internal standard as the abscissa, construct a standard curve reflecting the peak intensity and the polycyclic aromatic hydrocarbon concentration.

[0023] In one embodiment, when the polycyclic aromatic hydrocarbon is naphthalene, the internal standard is 8-deuteronaphthalene, and the derivative reagent is pyridine, the standard curve reflecting the peak intensity and the polycyclic aromatic hydrocarbon concentration is: Y1 = 1.2107 X1 + 0.000099, R 2 = 0.99; where Y1 is the ratio of the peak intensity of the naphthalene-pyridine adduct to the peak intensity of the 8-deuteronaphthalene-pyridine adduct; X1 is the ratio of the concentration of naphthalene to the concentration of the internal standard.

[0024] In one embodiment, when the polycyclic aromatic hydrocarbon is fluorene, the internal standard is 10-deuterofluorenene, and the derivative reagent is pyridine, the standard curve reflecting the peak intensity and the polycyclic aromatic hydrocarbon concentration is: Y2 = 1.6681 X2 + 0.00016, R 2 = 0.99; where Y2 is the ratio of the peak intensity of the fluorene-pyridine adduct to the peak intensity of the 10-deuterofluorenene-pyridine adduct; X2 is the ratio of the concentration of fluorene to the concentration of the internal standard.

[0025] In one embodiment, when the polycyclic aromatic hydrocarbon is acenaphthene, the internal standard is 10-deuteracenaphthene, and the derivative reagent is pyridine, the standard curve reflecting the peak intensity and the polycyclic aromatic hydrocarbon concentration is: Y3 = 1.0227 X3 - 0.0013, R 2 = 0.99; where Y3 is the ratio of the peak intensity of the acenaphthene-pyridine adduct to the peak intensity of the 10-deuteracenaphthene-pyridine adduct; X3 is the ratio of the concentration of acenaphthene to the concentration of the internal standard.

[0026] In one embodiment, preparing the series of polycyclic aromatic hydrocarbon standard solutions and the sample solution of the polycyclic aromatic hydrocarbon to be measured respectively includes:

[0027] Mix the polycyclic aromatic hydrocarbon with the first solvent to prepare standard intermediate solutions with different concentrations respectively;

[0028] Mix the internal standard and the derivative reagent with the second solvent to prepare an internal standard-derivative reagent mixture;

[0029] Add the internal standard-derivative reagent mixture to the polycyclic aromatic hydrocarbon sample to be measured to prepare the sample solution of the polycyclic aromatic hydrocarbon to be measured;

[0030] Into the intermediate solutions of the standard products with different concentrations, add the internal standard-derivatization reagent mixture to prepare multiple standard solutions of polycyclic aromatic hydrocarbons with different concentrations; wherein, in the multiple standard solutions of polycyclic aromatic hydrocarbons with different concentrations and the sample solution of the polycyclic aromatic hydrocarbons to be measured, the addition amounts of the internal standard-derivatization reagent mixture are the same.

[0031] In one embodiment, the first solvent and the second solvent each independently include one or more of acetonitrile, acetone, and isopropanol.

[0032] In one embodiment, in the series of standard solutions of polycyclic aromatic hydrocarbons, the molar ratio of the internal standard to the derivatization reagent is 1:(2-20).

[0033] In one embodiment, in the sample solution of the polycyclic aromatic hydrocarbons to be measured, the molar ratio of the internal standard to the derivatization reagent is 1:(2-20).

[0034] In one embodiment, the steps of separately ionizing the series of standard solutions of polycyclic aromatic hydrocarbons and the sample solution of the polycyclic aromatic hydrocarbons to be measured by electrochemically assisted electrospray ionization include:

[0035] SeparateIy inject the series of standard solutions of polycyclic aromatic hydrocarbons and the sample solution of the polycyclic aromatic hydrocarbons to be measured into a glass spray needle;

[0036] Place the glass spray needle in front of the mass spectrometry inlet, apply a voltage to the electrode in the glass spray needle to separately ionize the series of standard solutions of polycyclic aromatic hydrocarbons and the sample solution of the polycyclic aromatic hydrocarbons to be measured by electrochemically assisted electrospray ionization.

[0037] In one embodiment, the voltage applied to the electrode is 0.8 kV to 3 kV.

[0038] In one embodiment, the electrode includes one or more of a platinum wire electrode, a gold wire electrode, a silver wire electrode, and a carbon fiber electrode.

[0039] The beneficial effects of the method for detecting polycyclic aromatic hydrocarbons provided by this application at least include:

[0040] In this application, an internal standard and a derivatization reagent are added to a series of polycyclic aromatic hydrocarbon (PAH) standard solutions and the PAH sample solution to be measured. Combining with electrochemically assisted electrospray ionization, non-polar PAHs can be successively oxidized to radical cations, and the radical cations further react efficiently with the derivatization reagent to generate PAH derivatives with high ionization efficiency, so as to achieve on-line high-efficiency derivatization of PAHs. The high-efficiency ionization of PAHs gives full play to the advantages of rapid analysis by ESI-MS detection, so as to reduce the analysis time of samples, lower the detection limit of non-polar PAHs and improve the detection sensitivity of non-polar PAHs. Therefore, the detection method provided by this application has the advantages of rapidity, accuracy, high sensitivity and low detection limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic structural diagram of the electrochemically assisted electrospray ionization mass spectrometry device of this application;

[0042] Figure 2 It is a mass spectrum of naphthalene-pyridine adduct in Example 1;

[0043] Figure 3 It is an extracted ion chromatogram of naphthalene-pyridine adduct during the test in Example 1;

[0044] Figure 4 It is a standard curve graph reflecting peak intensity and naphthalene concentration in Example 1;

[0045] Figure 5 It is a mass spectrum of fluorene-pyridine adduct in Example 2;

[0046] Figure 6 It is a standard curve graph reflecting peak intensity and fluorene concentration in Example 2;

[0047] Figure 7 It is a mass spectrum of acenaphthene-pyridine adduct in Example 3;

[0048] Figure 8 It is a standard curve graph reflecting peak intensity and acenaphthene concentration in Example 3.

[0049] In the figure, 1 is a glass spray needle; 2 is an electrode; 3 is a mass spectrometry inlet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] The following further describes the detection method of polycyclic aromatic hydrocarbons of this application in a complete and clear manner in combination with specific embodiments. This application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of this application more thorough and comprehensive.

[0051] To improve the analysis speed of polycyclic aromatic hydrocarbons (PAHs), there are mainly the following direct mass spectrometry detection techniques: (1) Direct analysis in real time mass spectrometry (DART-MS), and (2) Dielectric barrier discharge ionization mass spectrometry (DBDI-MS). The above direct mass spectrometry detection techniques are conducive to ionizing non-polar compounds, converting non-polar compounds into radical cations to improve the ionization efficiency. At the same time, the above methods also do not require complex sample pretreatment steps and can detect non-polar compounds in various sample matrices. However, although the above methods can ionize PAHs, the ionized PAHs still have the disadvantage of low sensitivity during the ionization and mass spectrometry detection processes. In addition, traditional electrospray ionization (ESI) is mainly used for ionizing polar compounds, so it also has the disadvantage of being unsuitable for analyzing PAHs.

[0052] Based on this, in the first aspect of the present application, a detection method for polycyclic aromatic hydrocarbons is provided, including the following steps:

[0053] a1: Prepare a series of standard solutions of polycyclic aromatic hydrocarbons and a sample solution of polycyclic aromatic hydrocarbons to be measured respectively.

[0054] a2: After ionizing the series of standard solutions of polycyclic aromatic hydrocarbons and the sample solution of polycyclic aromatic hydrocarbons to be measured by electrochemically assisted electrospray method respectively, perform mass spectrometry detection.

[0055] a3: Construct a standard curve reflecting the peak intensity and the concentration of polycyclic aromatic hydrocarbons according to the detection results of the series of standard solutions of polycyclic aromatic hydrocarbons, and substitute the detection results of the sample solution of polycyclic aromatic hydrocarbons to be measured into the standard curve to obtain the concentration of polycyclic aromatic hydrocarbons in the sample solution of polycyclic aromatic hydrocarbons to be measured.

[0056] The detection method provided by the present application uses a common electrospray ion source. Without a special ion source, it can improve the ionization efficiency and detection sensitivity of non-polar polycyclic aromatic hydrocarbons. Further, the detection limit of the detection method for polycyclic aromatic hydrocarbons in the present application can be reduced to the fmol level, and its detection limit is significantly lower than that of GC-MS method, atmospheric pressure chemical ionization (APCI)-mass spectrometry, direct analysis in real time (DART)-mass spectrometry, and dielectric barrier discharge (DBDI)-mass spectrometry.

[0057] In addition, in the polycyclic aromatic hydrocarbon standard product series solution and the polycyclic aromatic hydrocarbon sample solution to be measured of the present application, an internal standard and a derivatization reagent are added, and in combination with electrochemically assisted electrospray method, non-polar polycyclic aromatic hydrocarbons can be successively oxidized into radical cations, and the radical cations further react efficiently with the derivatization reagent to generate polycyclic aromatic hydrocarbon derivatives with high ionization efficiency, so as to achieve on-line high-efficiency derivatization of polycyclic aromatic hydrocarbons. The high-efficiency ionization of polycyclic aromatic hydrocarbons greatly shortens the analysis time of a single sample, and the detection of a single sample can be achieved within 5 minutes. The analysis time is greatly shortened and the analysis rate is significantly improved. The high-efficiency ionization of polycyclic aromatic hydrocarbons gives full play to the advantages of rapid analysis by ESI-mass spectrometry detection, so as to reduce the analysis time of samples, reduce the detection limit of non-polar polycyclic aromatic hydrocarbons and improve the detection sensitivity of non-polar polycyclic aromatic hydrocarbons. Therefore, the detection method provided by the present application has the advantages of rapidity, accuracy, high sensitivity and low detection limit.

[0058] In one example, the polycyclic aromatic hydrocarbons include one or more of naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene and benzo[a]pyrene.

[0059] In one example, the polycyclic aromatic hydrocarbon sample to be measured is a flue gas sample. When tobacco burns at high temperature, it will produce various PAHs, such as naphthalene, acenaphthene, fluorene, benzo[a]pyrene, etc. These substances are potentially harmful to human health. Therefore, the detection method of the present application can detect flue gas samples.

[0060] In one example, in step a1, the polycyclic aromatic hydrocarbon standard product series solution includes polycyclic aromatic hydrocarbon standard solutions with multiple different concentrations. The polycyclic aromatic hydrocarbon standard product series solution and the polycyclic aromatic hydrocarbon sample solution to be measured include the same amount of internal standard and the same amount of derivatization reagent. It can be understood that in step a1, the polycyclic aromatic hydrocarbon standard product series solution includes: multiple different concentrations of naphthalene standard solutions, multiple different concentrations of acenaphthylene standard solutions, multiple different concentrations of acenaphthene standard solutions, multiple different concentrations of phenanthrene standard solutions, multiple different concentrations of anthracene standard solutions, multiple different concentrations of fluoranthene standard solutions, multiple different concentrations of pyrene standard solutions and multiple different concentrations of benzo[a]pyrene standard solutions.

[0061] In one example, in step a1, the steps of preparing the polycyclic aromatic hydrocarbon standard product series solution and the polycyclic aromatic hydrocarbon sample solution to be measured include:

[0062] a11: Mix the polycyclic aromatic hydrocarbons with a first solvent to respectively prepare standard intermediate solutions with different concentrations.

[0063] a12: Mix the internal standard and the derivatization reagent with a second solvent to prepare an internal standard-derivatization reagent mixture.

[0064] a13: Add the internal standard-derivatization reagent mixture to the polycyclic aromatic hydrocarbon sample to be tested to prepare the polycyclic aromatic hydrocarbon sample solution to be tested.

[0065] a14: Add the internal standard-derivatization reagent mixture to the intermediate standard solutions with different concentrations respectively to prepare multiple polycyclic aromatic hydrocarbon standard solutions with different concentrations.

[0066] Among the multiple polycyclic aromatic hydrocarbon standard solutions with different concentrations and the polycyclic aromatic hydrocarbon sample solution to be tested, the addition amounts of the internal standard-derivatization reagent mixture are the same.

[0067] In one example, in step a11, the concentrations of polycyclic aromatic hydrocarbons in the intermediate standard solutions with different concentrations are 0.1 µmol / L, 0.5 µmol / L, 1 µmol / L, 2.5 µmol / L, 5 µmol / L, 7.5 µmol / L, and 10 µmol / L respectively. Exemplarily, the naphthalene standard series solution includes multiple naphthalene standard solutions with different concentrations. The naphthalene standard series solutions respectively include naphthalene standard solutions with naphthalene concentrations of 0.1 µmol / L, 0.5 µmol / L, 1 µmol / L, 2.5 µmol / L, 5 µmol / L, 7.5 µmol / L, and 10 µmol / L. The fluorene standard series solution includes multiple fluorene standard solutions with different concentrations. The fluorene standard series solutions respectively include fluorene standard solutions with fluorene concentrations of 0.1 µmol / L, 0.5 µmol / L, 1 µmol / L, 2.5 µmol / L, 5 µmol / L, 7.5 µmol / L, and 10 µmol / L. The acenaphthene standard series solution includes multiple acenaphthene standard solutions with different concentrations. The acenaphthene standard series solutions respectively include acenaphthene standard solutions with acenaphthene concentrations of 0.1 µmol / L, 0.5 µmol / L, 1 µmol / L, 2.5 µmol / L, 5 µmol / L, 7.5 µmol / L, and 10 µmol / L.

[0068] In one example, the first solvent includes one or more of acetonitrile, acetone, and isopropanol.

[0069] In one example, the second solvent includes one or more of acetonitrile, acetone, and isopropanol.

[0070] In one example, in the series of solutions of polycyclic aromatic hydrocarbon standards, the molar ratio of the internal standard to the derivatization reagent is 1:(2 - 20). Understandably, in the series of solutions of polycyclic aromatic hydrocarbon standards, the molar ratio of the internal standard to the derivatization reagent includes but is not limited to 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20, or within the range formed by any two of the above point values as the end point values.

[0071] In one example, in the solution of the polycyclic aromatic hydrocarbon sample to be measured, the molar ratio of the internal standard to the derivatization reagent is 1:(2 - 20). Understandably, in the solution of the polycyclic aromatic hydrocarbon sample to be measured, the molar ratio of the internal standard to the derivatization reagent includes but is not limited to 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20, or within the range formed by any two of the above point values as the end point values.

[0072] In one example, the internal standard is the 13 C or deuterium isotope marker of the polycyclic aromatic hydrocarbon.

[0073] Exemplarily, the isotope markers of the polycyclic aromatic hydrocarbon include 13 C or deuterium-labeled: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene and benzo[a]pyrene. Understandably, in this application, the internal standard is the 13 C-substituted or deuterated isotope reagent corresponding to the polycyclic aromatic hydrocarbon to be measured. Exemplarily, when the polycyclic aromatic hydrocarbon contained in the series of solutions of polycyclic aromatic hydrocarbon standards is naphthalene, the internal standard is the 13 C-substituted or deuterated isotope reagent corresponding to naphthalene. When the polycyclic aromatic hydrocarbon contained in the series of solutions of polycyclic aromatic hydrocarbon standards is fluorene, the internal standard is the 13 C-substituted or deuterated isotope reagent corresponding to fluorene.

[0074] Exemplarily, the internal standard includes but is not limited to 8-deuterated naphthalene, 10-deuterated fluorene, 10-deuterated acenaphthene.

[0075] In one example, the derivatization reagent includes one or more of the compounds having the structures shown in Formula (I) - Formula (III):

[0076] 、 、 ; wherein, R 11 、R 12 、R 13Each is independently H or a C1-C6 alkyl group.

[0077] In the present application, "alkyl group" refers to a saturated hydrocarbon group including primary (n-), secondary, tertiary, or quaternary carbon atoms, or a combination thereof. A phrase containing this term, for example, "C1-C6 alkyl group" refers to an alkyl group containing 1 to 6 carbon atoms, and each occurrence may independently be a C1 alkyl group, a C2 alkyl group, a C3 alkyl group, a C4 alkyl group, a C5 alkyl group, or a C6 alkyl group. Suitable examples include but are not limited to: methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-propyl, n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-butyl, n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)CH2CH3), tert-butyl (1,1-dimethylethyl, 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2).

[0078] In formula (II), each occurrence of R2 is independently H, a hydroxyl group, a C1-C6 alkyl group, or a C1-C6 alkoxy group. m is any integer from 1 to 5. m is 1, 2, 3, 4, or 5.

[0079] In the present application, "alkoxy group" refers to a group having -O-alkyl, that is, the alkyl group as defined above is connected to the parent nucleus structure via an oxygen atom. A phrase containing this term, for example, "C1-C6 alkoxy group" means that the alkyl part contains 1 to 6 carbon atoms, and each occurrence may independently be a C1 alkoxy group, a C4 alkoxy group, a C5 alkoxy group, or a C6 alkoxy group. Suitable examples include but are not limited to: methoxy (-O-CH3 or -OMe), ethoxy (-O-CH2CH3 or -OEt), and tert-butoxy (-O-C(CH3)3 or -OtBu).

[0080] Exemplarily, the compounds of the structure shown in formula (II) include but are not limited to: pyridine , 2-methylpyridine , 2,3,4,5-tetramethylpyridine .

[0081] In formula (III), each occurrence of R3 is independently H, hydroxy, C1-C6 alkyl, or C1-C6 alkoxy; n is any integer from 1 to 7. n is 1, 2, 3, 4, 5, 6, or 7.

[0082] Exemplarily, the compounds of the structure shown in formula (III) include, but are not limited to: quinoline , 4-methylquinoline or 3-ethylquinoline .

[0083] In this application, the derivatization reagent is selected from one or more of the compounds having the structures shown in formula (I) - formula (III). The above derivatization reagent has strong nucleophilicity and mass spectrometry sensitization ability. It can efficiently react with polycyclic aromatic hydrocarbons by virtue of its strong nucleophilicity, and at the same time, significantly improve the detection sensitivity by using the mass spectrometry sensitization ability, which helps to detect the target more accurately and quickly.

[0084] In one example, in step a2, the steps of electrochemically assisted electrospray ionization of the polycyclic aromatic hydrocarbon standard series solution and the polycyclic aromatic hydrocarbon sample solution to be measured include:

[0085] a21: Inject the polycyclic aromatic hydrocarbon standard series solution and the polycyclic aromatic hydrocarbon sample solution to be measured into a glass spray needle respectively.

[0086] a22: Place the glass spray needle in front of the mass spectrometry inlet, and apply a voltage to the electrode in the glass spray needle to electrochemically assist electrospray ionization of the polycyclic aromatic hydrocarbon standard series solution and the polycyclic aromatic hydrocarbon sample solution to be measured respectively.

[0087] In one example, the voltage applied to the electrode is 0.8 kV - 3 kV. Exemplarily, the voltage applied to the electrode includes, but is not limited to, 0.8 kV, 0.9 kV, 1 kV, 1.2 kV, 1.4 kV, 1.6 kV, 1.8 kV, 2 kV, 2.2 kV, 2.4 kV, 2.6 kV, 2.8 kV, or 3 kV, or within the range formed by any two of the above point values as the end point values.

[0088] In one example, the electrode includes one or more of a platinum wire electrode, a gold wire electrode, a silver wire electrode, and a carbon fiber electrode.

[0089] In one example, the horizontal distance between the needle tip of the glass spray needle and the mass spectrometry inlet is 3 mm to 8 mm. Exemplarily, the horizontal distance between the needle tip of the spray needle and the mass spectrometry inlet includes, but is not limited to, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 4.8 mm, 4.9 mm, 5 mm, 5.1 mm, 5.2 mm, 5.5 mm, 5.8 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, or 8 mm, or any range formed by any two of the above point values as the end point values.

[0090] Specifically, the structural schematic diagram of the electrochemical-assisted electrospray ionization mass spectrometry device of the present application is as Figure 1 shown. As Figure 1 can be seen, an electrode 2 is inserted into the glass spray needle 1, and the needle tip of the glass spray needle 1 is placed in front of the mass spectrometry inlet 3. At this time, by applying an electrode to the electrode 2, polycyclic aromatic hydrocarbons PAH can be oxidized to radical cations , radical cations further react with a derivatizing reagent such as pyridine to form a polycyclic aromatic hydrocarbon-derivatizing reagent adduct, such as a polycyclic aromatic hydrocarbon-pyridine adduct and so on.

[0091] In one example, the parameters for mass spectrometry detection include: the ionization mode is the positive ion mode.

[0092] In one example, the parameters for mass spectrometry detection include: the mass spectrometry scanning mode is the multiple reaction monitoring (MRM) mode.

[0093] In one example, the parameters for mass spectrometry detection include: the curtain gas pressure is 8 psi to 15 psi. Exemplarily, the curtain gas pressure includes, but is not limited to, 8 psi, 9 psi, 10 psi, 11 psi, 12 psi, 13 psi, 14 psi, or 15 psi, or any range formed by any two of the above point values as the end point values.

[0094] In one example, the parameters for mass spectrometry detection include: the collision cell exit potential is 8 volts to 15 volts. Exemplarily, the collision cell exit potential includes, but is not limited to, 8 volts, 9 volts, 10 volts, 11 volts, 12 volts, 13 volts, 14 volts, or 15 volts, or any range formed by any two of the above point values as the end point values.

[0095] In one example, the parameters for mass spectrometry detection include: the heating temperature is 140 °C to 160 °C. Exemplarily, the heating temperature includes, but is not limited to, 140 °C, 145 °C, 150 °C, 155 °C, or 160 °C, or any range formed by any two of the above point values as the end point values.

[0096] In one example, in step a3, the step of constructing a standard curve reflecting peak intensity and polycyclic aromatic hydrocarbon concentration based on the detection results of the series of polycyclic aromatic hydrocarbon standard solutions includes:

[0097] a31: respectively obtain the peak intensity of the polycyclic aromatic hydrocarbon-derivative reagent adduct and the peak intensity of the internal standard-derivative reagent adduct in the series of polycyclic aromatic hydrocarbon standard solutions;

[0098] a32: taking the ratio of the peak intensity of the polycyclic aromatic hydrocarbon-derivative reagent adduct to the peak intensity of the internal standard-derivative reagent adduct as the ordinate, and taking the ratio of the polycyclic aromatic hydrocarbon concentration in the series of polycyclic aromatic hydrocarbon standard solutions to the internal standard concentration as the abscissa, construct a standard curve reflecting peak intensity and polycyclic aromatic hydrocarbon concentration.

[0099] It can be understood that the peak intensity of the above polycyclic aromatic hydrocarbon-derivative reagent adduct and the peak intensity of the above internal standard-derivative reagent adduct are both the average peak intensity I within the period from the start of spray detection to the disappearance of the signal.

[0100] In one example, when the polycyclic aromatic hydrocarbon is naphthalene, the internal standard is 8-deuterated naphthalene, and the derivative reagent is pyridine. The standard curve reflecting peak intensity and polycyclic aromatic hydrocarbon concentration is: Y1 = 1.2107 X1 + 0.000099, R 2 = 0.99; where Y1 is the ratio of the peak intensity of the naphthalene-pyridine adduct to the peak intensity of the 8-deuterated naphthalene-pyridine adduct; X1 is the ratio of the concentration of naphthalene to the internal standard concentration.

[0101] In one example, when the polycyclic aromatic hydrocarbon is fluorene, the internal standard is 10-deuterated fluorene, and the derivative reagent is pyridine, the standard curve reflecting peak intensity and polycyclic aromatic hydrocarbon concentration is: Y2 = 1.6681 X2 + 0.00016, R 2 = 0.99; where Y2 is the ratio of the peak intensity of the fluorene-pyridine adduct to the peak intensity of the 10-deuterated fluorene-pyridine adduct; X2 is the ratio of the concentration of fluorene to the internal standard concentration.

[0102] In one example, when the polycyclic aromatic hydrocarbon is acenaphthene, the internal standard is 10-deuterated acenaphthene, and the derivative reagent is pyridine, the standard curve reflecting peak intensity and polycyclic aromatic hydrocarbon concentration is: Y3 = 1.0227 X3 - 0.0013, R 2 = 0.99; where Y3 is the ratio of the peak intensity of the acenaphthene-pyridine adduct to the peak intensity of the 10-deuterated acenaphthene-pyridine adduct; X3 is the ratio of the concentration of acenaphthene to the internal standard concentration.

[0103] In this application, acenaphthene refers to an organic compound with the structure of ​

[0104] Understandably, when the polycyclic aromatic hydrocarbon sample solution to be measured contains multiple polycyclic aromatic hydrocarbons, the detection can be carried out sequentially for different types of polycyclic aromatic hydrocarbons.

[0105] In a second aspect of the present application, there is provided a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements at least one step of the method for detecting polycyclic aromatic hydrocarbons described in any example of the first aspect of the present application.

[0106] Further specific embodiments are used to illustrate the present application in detail. It should also be understood that the following embodiments are only used to further illustrate the present application and cannot be construed as limiting the protection scope of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application fall within the protection scope of the present application. The specific process parameters and the like in the following embodiments are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, and do not necessarily have to be limited to the specific values in the following embodiments.

[0107] Example 1

[0108] When the internal standard is 8-deuterated naphthalene and the derivatization reagent is pyridine, the method for detecting the concentration of naphthalene in the flue gas sample solution to be measured includes:

[0109] (1) Set up an electrochemically assisted derivatization nanoelectrospray ionization device: Pull a borosilicate glass capillary (B100-58-10) into a glass needle using a P-2000 laser puller (Sutter Instrument Company, USA). The pulling parameters are set as follows: heating temperature 420 °C, filament diameter 5 mm, pulling speed 28, delay time 125, pulse width 80. Insert a platinum wire (diameter 200 µm) into the glass needle until the tip as an electrode, and connect the other end to a high-voltage power supply, and adjust the voltage to 1.4 kV. Place the needle end of the glass needle in front of a commercial mass spectrometer LTQ Orbitrap Velos or QTRAP@4500 (as Figure 1 shown).

[0110] (2) Use the LTQ Orbitrap Velos mass spectrometer to observe and confirm the formation of the derivatized product. Among them, the mass-to-charge ratio m / z of the naphthalene-pyridine adduct is 206.0955 ( Figure 2 ).

[0111] (3) Preparation of intermediate solutions of naphthalene standards: Mix naphthalene with acetonitrile solvent to prepare intermediate solutions of naphthalene standards with different concentrations. Among them, the molar concentrations of naphthalene in the intermediate solutions of naphthalene standards are 0.2 µmol / L, 1 µmol / L, 2 µmol / L, 5 µmol / L, 10 µmol / L, 15 µmol / L, and 20 µmol / L respectively.

[0112] (4) Preparation of internal standard-derivatization reagent mixed solution: Mix 8-deuterated naphthalene and pyridine to prepare an internal standard-derivatization reagent mixed solution. Among them, in the internal standard-derivatization reagent mixed solution, the molar concentration of 8-deuterated naphthalene is 20 µmol / L, and the molar concentration of pyridine is 50 µmol / L.

[0113] (5) Preparation of a series of naphthalene standard solutions: Mix the above-mentioned intermediate solutions of naphthalene standards with different concentrations and the internal standard-derivatization reagent mixed solution in a volume ratio of 1:1 to prepare a series of naphthalene standard solutions with different concentrations. The series of naphthalene standard solutions with different concentrations constitutes a series of naphthalene standard solutions.

[0114] (6) Prepare a test flue gas sample solution, and the volume of the internal standard-derivatization reagent mixed solution added to the test flue gas sample solution is the same as the volume of the internal standard-derivatization reagent mixed solution added to the series of naphthalene standard solutions.

[0115] (7) Use a microsyringe to add 2 µL of the series of naphthalene standard solutions and the test flue gas sample solution to a glass injection needle respectively, insert a platinum wire electrode, and combine it with QTRAP@4500 (AB SCIEX, USA) for quantitative detection. The voltage is set to 1.4 kV, the horizontal distance between the tip of the glass injection needle and the MS inlet is 5 mm, and the vertical distance between them is 3 mm. The MS parameters are set as follows: positive ion; multiple reaction monitoring (MRM) mode; curtain gas, 10 psi; collision cell outlet potential: 10 V, heating temperature: 150 °C. Under multiple reaction monitoring, the information of the precursor ion and product ion pairs generated by naphthalene and 8-deuterated naphthalene with the derivatization reagent pyridine is shown in Table 1 below:

[0116] Table 1

[0117]

[0118] (8) According to the time period from the start to the end of the signal in the ion current chromatogram (as shown in Figure 3 ), obtain the average peak intensities of naphthalene-pyridine adducts and 8-deuterated naphthalene-pyridine adducts in different test samples respectively, and calculate the signal ratio of the adducts generated by naphthalene and its isotope (8-deuterated naphthalene).

[0119] (9) Using the naphthalene concentration (CNap ), and the ratio of the concentration of 8-deuterated naphthalene (C Nap-D8 ) as the abscissa (X), and the peak intensity of the naphthalene-pyridine adduct (I Nap ) and the peak intensity of the 8-deuterated naphthalene-pyridine adduct (I Nap-D8 ) as the ordinate (Y) to plot a graph; perform a linear fit on the data points in the graph to obtain a linear equation (as shown in Figure 4 ), and at this time the standard curve is: Y = 1.2107X + 0.000099, R 2 = 0.99, and the linear range is 0.05 - 10 μmol / L (response signal of the detector).

[0120] (10) Substitute the ratio of the peak intensity of the naphthalene-pyridine adduct and the peak intensity of the 8-deuterated naphthalene-pyridine adduct measured in the flue gas sample to be measured into the linear equation, calculate the X value, and since the internal standard concentration in the flue gas sample to be measured is known, the naphthalene concentration in the flue gas sample solution can be calculated.

[0121] Example 2

[0122] When the internal standard is 10-deuterated fluorene and the derivatization reagent is pyridine, the detection method for the fluorene concentration in the flue gas sample solution to be measured includes:

[0123] (1) Set up an electrochemically assisted derivatization nanoelectrospray ionization device: Pull a borosilicate glass capillary (B100 - 58 - 10) into a glass needle using a P - 2000 laser puller (Sutter Instrument Company, USA). The pulling parameters are set as follows: heating temperature 420 °C, filament diameter 5 mm, pulling speed 28, delay time 125, pulse width 80. Insert a platinum wire (diameter 200 µm) into the glass needle until the tip as an electrode, and connect the other end to a high-voltage power supply, and adjust the voltage to 1.4 kV. Place the tip of the glass needle in front of a commercial mass spectrometer LTQ Orbitrap Velos or QTRAP@4500 (as shown in Figure 1 ).

[0124] (2) Use the LTQ Orbitrap Velos mass spectrometer to observe and confirm the formation of the derivatization product. Among them, the mass-to-charge ratio m / z of the fluorene-pyridine adduct is 244.1132 ( Figure 5 ).

[0125] (3) Preparation of the intermediate solution of the fluorene standard: Mix fluorene and acetonitrile solvent to prepare intermediate solutions of fluorene standards with different concentrations; among them, in the intermediate solutions of fluorene standards, the molar concentrations of fluorene are: 0.2 µmol / L, 1 µmol / L, 2 µmol / L, 5 µmol / L, 10 µmol / L, 15 µmol / L, 20 µmol / L.

[0126] (4)Preparation of internal standard-derivatization reagent mixed solution: Mix 10-deuterated fluorene and pyridine to prepare the internal standard-derivatization reagent mixed solution; among them, in the internal standard-derivatization reagent mixed solution, the molar concentration of 10-deuterated fluorene is 20 μmol / L, and the molar concentration of pyridine is 50 μmol / L.

[0127] (5)Preparation of fluorene standard series solutions: Mix the above-mentioned intermediate solutions of fluorene standards with different concentrations and the internal standard-derivatization reagent mixed solution in a volume ratio of 1:1 to prepare fluorene standard solutions with different concentrations. The fluorene standard solutions with different concentrations form a fluorene standard series solution.

[0128] (6)Prepare the test flue gas sample solution, and the volume of the internal standard-derivatization reagent mixed solution added to the test flue gas sample solution is the same as the volume of the internal standard-derivatization reagent mixed solution added to the fluorene standard series solution.

[0129] (7)Use a microsyringe to add 2 μL of the fluorene standard series solution and the test flue gas sample solution to the glass spray needle respectively, insert the platinum wire electrode, and combine with QTRAP@4500 (AB SCIEX, USA) for quantitative detection. The voltage is set to 1.4 kV, the horizontal distance between the tip of the glass spray needle and the MS inlet is 5 mm, and the vertical distance between them is 3 mm. The MS parameters are set as follows: positive ion; multiple reaction monitoring (MRM) mode; curtain gas, 10 psi; collision cell outlet potential: 10 V, heating temperature: 150 °C. Under multiple reaction monitoring, the information of the precursor ion and product ion pairs generated by fluorene and 10-deuterated fluorene with the derivatization reagent pyridine is shown in Table 2 below:

[0130] Table 2

[0131]

[0132] (8)According to the time period from the start to the end of the signal in the ion flow chromatogram, obtain the average peak intensities of the fluorene-pyridine adduct and the 10-deuterated fluorene-pyridine adduct in different test samples respectively, and calculate the signal ratio of the adducts generated by fluorene and its isotope (10-deuterated fluorene).

[0133] (9)Take the ratio of the concentration of fluorene (C flu )and the concentration of 10-deuterated fluorene (C flu-D10 )in the fluorene standard series solution as the abscissa (X), and the peak intensity of the fluorene-pyridine adduct (I flu )and the ratio of the peak intensities of the 10-deuterated fluorene-pyridine adduct (I flu-D10)(Y) is used as the ordinate for plotting; perform linear fitting on the data points in the figure to obtain a linear equation (as Figure 6 shown), and at this time the standard curve is: Y = 1.6681 X + 0.00016 (R 2 = 0.99), and the linear range is 0.1 - 10 μmol / L (response signal of the detector).

[0134] (10) Substitute the ratio of the peak intensity of the fluorene - pyridine adduct and the peak intensity of the 10 - deuterated fluorene - pyridine adduct measured in the flue gas sample to be tested into the linear equation to calculate the X value. Since the internal standard concentration in the flue gas sample to be tested is known, the fluorene concentration in the flue gas sample solution can be obtained by calculation.

[0135] Example 3

[0136] When the internal standard is 10 - deuterated acenaphthene and the derivatization reagent is pyridine, the method for detecting the fluorene concentration in the flue gas sample solution includes:

[0137] (1) Set up an electrochemically assisted derivatization nano - spray ionization device: Pull a borosilicate glass capillary (B100 - 58 - 10) into a glass spray needle through a P - 2000 laser puller (Sutter Instrument Company, USA). The pulling parameters are set as follows: heating temperature 420 °C, filament diameter 5 mm, pulling speed 28, delay time 125, pulse width 80. Insert a platinum wire (diameter 200 µm) into the glass spray needle until the tip as the electrode, and connect the other end to a high - voltage power supply, and adjust the voltage to 1.4 kV. Place the needle end of the glass spray needle in front of a commercial mass spectrometer LTQ Orbitrap Velos or QTRAP@4500 (as Figure 1 shown).

[0138] (2) Use the LTQ Orbitrap Velos mass spectrometer to observe and confirm the formation of the derivatization product. Among them, the mass - to - charge ratio m / z of the fluorene - pyridine adduct is 232.1131.

[0139] (3) Preparation of the intermediate solution of the acenaphthene standard: Mix acenaphthene and acetonitrile solvent to prepare intermediate solutions of acenaphthene standards with different concentrations; among them, in the intermediate solutions of acenaphthene standards, the molar concentrations of acenaphthene are: 0.2 μmol / L, 1 μmol / L, 2 μmol / L, 5 μmol / L, 10 μmol / L, 15 μmol / L, 20 μmol / L.

[0140] (4) Preparation of the internal standard - derivatization reagent mixed solution: Mix 10 - deuterated acenaphthene and pyridine to prepare the internal standard - derivatization reagent mixed solution; among them, in the internal standard - derivatization reagent mixed solution, the molar concentration of 10 - deuterated acenaphthene is 20 μmol / L, and the molar concentration of pyridine is 50 μmol / L.

[0141] (5) Preparation of acenaphthene standard solution series: Mix the above-mentioned intermediate solutions of acenaphthene standards with different concentrations and the internal standard-derivatization reagent mixed solution in a volume ratio of 1:1 to prepare multiple acenaphthene standard solutions with different concentrations. The multiple acenaphthene standard solutions with different concentrations form the acenaphthene standard solution series.

[0142] (6) Prepare the flue gas sample solution to be measured. The volume of the internal standard-derivatization reagent mixed solution added to the flue gas sample solution to be measured is the same as that added to the acenaphthene standard solution series.

[0143] (7) Use a microsyringe to add 2 μL of the acenaphthene standard solution series and the flue gas sample solution to be measured into a glass spray needle respectively, insert a platinum wire electrode, and combine it with QTRAP@4500 (AB SCIEX, USA) for quantitative detection. The voltage is set to 1.4 kV, the horizontal distance between the tip of the glass spray needle and the MS inlet is 5 mm, and the vertical distance between them is 3 mm. The MS parameters are set as follows: positive ion; multiple reaction monitoring (MRM) mode; curtain gas, 10 psi; collision cell outlet potential: 10 V, heating temperature: 150 °C. Under multiple reaction monitoring, the precursor ion and product ion pairs generated by acenaphthene and 10-deuterated acenaphthene with the derivatization reagent pyridine are shown in Table 3 below:

[0144] Table 3

[0145]

[0146] (8) According to the time period from the start to the end of the signal in the ion current chromatogram, obtain the average peak intensities of the acenaphthene-pyridine adduct and the 10-deuterated acenaphthene-pyridine adduct in different test samples respectively, and calculate the signal ratio of the adducts generated by acenaphthene and its isotope (10-deuterated acenaphthene).

[0147] (9) Take the ratio of the concentration of fluorene (C ace ) and the concentration of 10-deuterated acenaphthene (C ace-D10 ) in the acenaphthene standard solution series as the abscissa (X), and the ratio of the peak intensity of the acenaphthene-pyridine adduct (I ace ) and the peak intensity of the 10-deuterated acenaphthene-pyridine adduct (I ace-D10 ) as the ordinate (Y) to plot a graph; perform linear fitting on the data points in the graph to obtain a linear equation (as shown in Figure 8 ). At this time, the standard curve is: Y = 1.0227 X - 0.0013 (R 2 = 0.99), and the linear range is 0.1~10 μmol / L (response signal of the detector).

[0148] (10) Substitute the ratio of the peak intensity of the acenaphthene-pyridine adduct to the peak intensity of the 10-deuterated acenaphthene-pyridine adduct measured in the flue gas sample to be tested into the linear equation to calculate the value of X. Since the concentration of the internal standard in the flue gas sample to be tested is known, the concentration of acenaphthene in the flue gas sample solution to be tested can be obtained by calculation.

[0149] The values of the naphthalene concentration, fluorene concentration, and acenaphthene concentration in the flue gas sample solution to be tested calculated by the linear equation in the above Examples 1 to 3 are shown in Table 4 respectively; at the same time, to verify the effectiveness of the test method of the present application, the values of the naphthalene concentration, fluorene concentration, and acenaphthene concentration in the flue gas sample solution to be tested obtained by the GC-MS method are also shown in Table 4.

[0150] Table 4

[0151]

[0152] As can be seen from Table 4, the contents of naphthalene, fluorene, and acenaphthene detected in the flue gas sample solution to be tested in the present application are consistent with those of GC-MS. This shows that the detection method of the present application can achieve accurate quantitative detection of polycyclic aromatic hydrocarbons in flue gas samples in a short time, and this method has high detection sensitivity and accurate detection results.

[0153] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0154] The above-described embodiments only represent several implementation manners of the present application, which are convenient for understanding the technical solutions of the present application specifically and in detail, but should not be construed as a limitation on the protection scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can be made, and these all belong to the protection scope of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments based on the technical solutions provided by the present application are all within the protection scope of the appended claims of the present application. Therefore, the protection scope of the patent of the present application should be subject to the content of the appended claims, and the specification can be used to explain the content of the claims.

Claims

1. A method for detecting polycyclic aromatic hydrocarbons, characterized in that: The following steps are involved: Prepare a series of PAH standard solutions and a PAH sample solution to be tested respectively; wherein the PAH standard solution series includes a plurality of PAH standard solutions of different concentrations; the PAH standard solution series and the PAH sample solution to be tested include the same amount of internal standard and the same amount of derivatization reagent; After ionizing the PAH standard series solution and the PAH sample solution to be tested respectively by electrochemical-assisted electrospray ionization, mass spectrometry detection is performed; A standard curve reflecting peak intensity and PAH concentration is constructed according to the detection results of the PAH standard series solutions, and the detection results of the PAH sample solution to be tested are substituted into the standard curve to obtain the concentration of PAHs in the PAH sample solution to be tested.

2. The method for detecting polycyclic aromatic hydrocarbons according to claim 1, characterized in that: The detection method has one or more of the following characteristics: (1) The polycyclic aromatic hydrocarbons include one or more of naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene and benzopyrene; (2) The internal standard is the polycyclic aromatic hydrocarbons 13 C or deuterium isotope labeling; (3) The derivatization reagent includes one or more compounds having structures represented by formula (I) to formula (III): , , ; Among them, R 11 , R 12 , R 13 Each is independently H or C1~C6 alkyl; R2, when it appears each time, is independently H, hydroxyl, C1~C6 alkyl or C1~C6 alkoxy; m is an integer from 1 to 5; R3, when it appears each time, is independently H, hydroxyl, C1~C6 alkyl or C1~C6 alkoxy; n is an integer from 1 to 7.

3. The method for detecting polycyclic aromatic hydrocarbons according to claim 1, characterized in that: The parameters for mass spectrometry detection have one or more of the following characteristics: (1) The ionization mode is positive ion mode; (2) The mass spectrometry scanning mode is multiple reaction monitoring (MRM) mode; (3) The air curtain pressure is 8psi~15psi; (4) The collision cell exit potential is 8V to 15V; (5) The heating temperature is 140℃~160℃.

4. The method for detecting polycyclic aromatic hydrocarbons according to claim 1, characterized in that: The step of constructing a standard curve reflecting peak intensity and polycyclic aromatic hydrocarbon concentration according to the detection results of the polycyclic aromatic hydrocarbon standard series solution comprises: Respectively obtaining the peak intensity of the polycyclic aromatic hydrocarbon-derivative reagent adduct and the peak intensity of the internal standard-derivative reagent adduct in the polycyclic aromatic hydrocarbon standard series solution; A standard curve reflecting peak intensity and PAH concentration is constructed with the ratio of the peak intensity of the PAH-derivative reagent adduct to the peak intensity of the internal standard-derivative reagent adduct as the ordinate and the ratio of the PAH concentration in the PAH standard series solution to the internal standard concentration as the abscissa.

5. The method for detecting polycyclic aromatic hydrocarbons according to any one of claims 1 to 4, characterized in that: The standard curve has one or more of the following characteristics: (1) When the PAH is naphthalene, the internal standard is 8-d naphthalene, and the derivatization reagent is pyridine, the standard curve reflecting the peak intensity and PAH concentration is: Y1 = 1.2107 X1 + 0.000099, R 2 =0.99; wherein Y1 is the ratio of the peak intensity of the naphthalene-pyridine adduct to the peak intensity of the 8-deuterated naphthalene-pyridine adduct; X1 is the ratio of the concentration of naphthalene to the internal standard concentration; (2) When the PAH is fluorene, the internal standard is 10-d fluorene, and the derivatization reagent is pyridine, the standard curve reflecting the peak intensity and PAH concentration is: Y2 = 1.6681 X2 +0.00016, R 2 =0.99; wherein Y2 is the ratio of the peak intensity of the fluorene-pyridine adduct to the peak intensity of the 10-deuterated fluorene-pyridine adduct; X2 is the ratio of the concentration of fluorene to the internal standard concentration; (3) When the PAH is acenaphthene, the internal standard is 10-d acenaphthene, and the derivatization reagent is pyridine, the standard curve reflecting the peak intensity and PAH concentration is: Y3 = 1.0227 X3 - 0.0013, R 2 =0.99; wherein Y3 is the ratio of the peak intensity of acenaphthene-pyridine adduct to the peak intensity of 10-deuterated acenaphthene-pyridine adduct; and X3 is the ratio of the concentration of acenaphthene to the internal standard concentration.

6. The method for detecting polycyclic aromatic hydrocarbons according to any one of claims 1 to 4, characterized in that: The preparation of PAH standard solution series and PAH sample solution to be tested includes: The polycyclic aromatic hydrocarbons are mixed with the first solvent to prepare standard intermediate solutions of different concentrations; mixing the internal standard and the derivatization reagent with a second solvent to prepare an internal standard-derivation reagent mixed solution; Adding the internal standard-derivatization reagent mixed solution to the PAH sample to be tested to prepare the PAH sample solution to be tested; The internal standard-derivatization reagent mixture is added to the standard intermediate solutions of different concentrations to prepare a plurality of PAH standard solutions of different concentrations; wherein the amount of the internal standard-derivatization reagent mixture added to the PAH standard solutions of different concentrations and the PAH sample solution to be tested is the same.

7. The method for detecting polycyclic aromatic hydrocarbons according to claim 6, characterized in that: The first solvent and the second solvent each independently include one or more of acetonitrile, acetone and isopropanol.

8. The method for detecting polycyclic aromatic hydrocarbons according to any one of claims 1 to 4, characterized in that: In the PAH standard series solution, the molar ratio of the internal standard to the derivatization reagent is 1:(2-20); And / or, in the PAH sample solution to be tested, the molar ratio of the internal standard to the derivatization reagent is 1:(2-20).

9. The method for detecting polycyclic aromatic hydrocarbons according to any one of claims 1 to 4, characterized in that: The steps of ionizing the PAH standard series solution and the PAH sample solution to be tested respectively by electrochemical assisted electrospray method include: Respectively injecting the PAH standard series solution and the PAH sample solution to be tested into a glass spray needle; The glass spray needle is placed in front of the mass spectrometer inlet, and a voltage is applied to the electrode in the glass spray needle to ionize the polycyclic aromatic hydrocarbon standard series solution and the polycyclic aromatic hydrocarbon sample solution to be tested respectively through an electrochemical assisted electrospray method.

10. The method for detecting polycyclic aromatic hydrocarbons according to claim 9, characterized in that: The voltage applied to the electrodes is 0.8 kV to 3 kV; And / or, the electrode includes one or more of a platinum wire electrode, a gold wire electrode, a silver wire electrode and a carbon fiber electrode.

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