A method for analyzing cyclic phosphazene flame retardants in environmental solid matrix based on LC-MS / MS technology

Abstract

The application discloses a method for analyzing cyclotriphosphazene flame retardants in environmental solid matrix based on LC-MS / MS technology, which comprises the following steps: after collecting and processing and screening the sample to be measured, using a mixed solvent (acetonitrile: dichloromethane: methyl tert-butyl ether = 2:2:1; v:v:v) for extraction, after vortex mixing, ultrasonic extraction and high-speed centrifugation, transferring the supernatant to another centrifuge tube, repeating the extraction twice, and combining the supernatant. Blow to near dry under mild nitrogen, add 1mL acetonitrile, and filter through a 0.22mu m membrane for instrument analysis. The method provided by the application has high sensitivity and reliable data, and has important significance for the subsequent research of cyclotriphosphazene flame retardants in environmental sample matrix.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical detection technology, in particular to a method for analyzing cyclotriphosphazene flame retardants in environmental solid matrix based on LC-MS / MS technology. BACKGROUND

[0002] Flame retardants are widely used in aerospace, chemical building materials, transportation and indoor decoration and other aspects of daily life as a substance that can inhibit the spread of fire, reduce the flammability of materials and improve the fire resistance of materials. Cyclotriphosphazene (CTP) is a new type of organic phosphorus flame retardant with stable six-membered ring conjugated structure, high thermal stability and light stability. Cyclotriphosphazene flame retardants are widely used and have environmental persistence and biological accumulation, which poses a great risk to the ecological environment and human health and needs close attention.

[0003] So far, there have been few studies on cyclotriphosphazene flame retardants, and no systematic method for analyzing and detecting cyclotriphosphazene flame retardants in environmental solid matrix samples has been developed. Therefore, the present application can provide a reference for the detection method of cyclotriphosphazene flame retardants in environmental media. SUMMARY

[0004] The purpose of the present application is to provide a method for analyzing cyclotriphosphazene flame retardants in environmental solid matrix based on LC-MS / MS technology to solve the problems raised in the background.

[0005] The present application provides the following technical solution: a method for analyzing cyclotriphosphazene flame retardants in environmental solid matrix based on LC-MS / MS technology, which detects six cyclotriphosphazene flame retardants, PFPCTP, EPFCTP, HFCTP, HCCTP, HMCTP and HPCTP, in the sample after pretreatment of the target pollutants in the solid matrix sample by extraction and concentration, to fill the gap in the detection method of cyclotriphosphazene flame retardants in environmental solid matrix samples at home and abroad, and to provide a reference for the detection of cyclotriphosphazene flame retardants in environmental matrix samples, including the following steps:

[0006] Step (1) Pretreatment of the sample to be tested: The collected sample to be tested is sieved through a stainless steel screen (150 μm) and stored in an amber glass jar at a temperature of -20°C until analysis; 50 mg of the sample is weighed into a glass centrifuge tube, 2 mL of mixed solvent (acetonitrile: dichloromethane: methyl tert-butyl ether = 2:2:1; v:v:v) is added, vortexed for 10 min, ultrasonically extracted for 20 min, and centrifuged at 3600 r / min for 10 min, then the supernatant is transferred to another centrifuge tube; repeat the extraction twice and combine the supernatants; under gentle nitrogen, the solution is blown to near dryness, 1 mL of acetonitrile is added and filtered through a 0.22 μm filter for instrument analysis;

[0007] Step (2) LC-MS / MS detection: sample analysis was performed using an Exion LC AC ultra-performance liquid chromatography-triple quadrupole mass spectrometry (LC-MS / MS; AB Sciex, Framingham, MA) in positive or negative electrospray ionization (ESI) mode, using multiple reaction monitoring (MRM) mode to collect data; sample separation was performed using an XBridge BEH C8 column (100 mm x 2.1 mm, 2.5 μm, Waters) at a flow rate of 0.25 mL / min, with a sample volume of 5 μL, a column temperature of 40 °C, and mobile phases of (A) 5 mM ammonium acetate in water and (B) methanol.

[0008] According to the above technical solution, a 150 μm stainless steel screen is used when the sample to be tested is sieved in step (1).

[0009] According to the above technical solution, the mixed extraction solvent in step (1) is acetonitrile: dichloromethane: methyl tert-butyl ether = 2:2:1; v:v:v.

[0010] According to the above technical solution, the vortexing time in step (1) is 10 ± 2 min, the ultrasonic time is 20 ± 2 min, and the centrifugation speed is 3600 ± 200 rpm for 10 ± 2 min.

[0011] According to the above technical solution, the detection conditions of the high-performance liquid chromatography-triple quadrupole mass spectrometry instrument in step (2) are as follows: Waters XBridge BEH C8 is selected as the liquid chromatography analysis column, the length of the liquid chromatography column is 100 mm, the inner diameter is 2.1 mm, and the filler particle diameter is 2.5 μm; positive or negative ionization electrospray (ESI) mode is used, the positive ion mode detection conditions are as follows: ion source spray voltage: 5500 V, ion source temperature: 550 °C, spray gas: 45 psi, auxiliary heating gas: 45 psi, curtain gas: 35 psi, and collision gas: 7 psi; the negative ion mode detection conditions are as follows: ion source spray voltage: -4500 V, ion source temperature: 550 °C, auxiliary heating gas: 45 psi, curtain gas: 35 psi, and collision gas: 7 psi.

[0012] According to the above technical solution, PFPCTP, EPFCTP, HFCTP, and HCCTP are analyzed in negative ion mode, and HMCTP and HPCTP are analyzed in positive ion mode in step (2).

[0013] According to the technical scheme, the mobile phase in step (2) is (A) 5mM ammonium acetate aqueous solution and (B) methanol, and the gradient is: 0-1min, 10% B; 1-2min, 10-100% B; 2-8min, 100% B; 8-9min, 100-10% B; 9-14min, 10% B.

[0014] Compared with the prior art, the present application has the advantages that the present application can quantitatively analyze six cyclotriphosphazene flame retardants, the detection method is high in precision and stable, can provide certain reference for detecting cyclotriphosphazene flame retardants in environmental matrices, and is convenient for subsequent research and development. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the present application together with the embodiments thereof, and explain the present application, but do not constitute a limitation on the present application. In the drawings:

[0016] Figure 1 FIG. 1 is a total ion chromatogram of the present application based on LC-MS / MS detection of indoor dust samples in negative ion mode for four cyclotriphosphazene flame retardants;

[0017] Figure 2 FIG. 2 is a total ion chromatogram of the present application based on LC-MS / MS detection of indoor dust samples in positive ion mode for two cyclotriphosphazene flame retardants;

[0018] Figure 3 FIG. 3 is a total ion chromatogram of the present application based on LC-MS / MS detection of soil samples beside urban roads in negative ion mode for four cyclotriphosphazene flame retardants;

[0019] Figure 4 FIG. 4 is a total ion chromatogram of the present application based on LC-MS / MS detection of soil samples beside urban roads in positive ion mode for two cyclotriphosphazene flame retardants. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0021] Please refer to Figures 1-4 The present application provides a technical solution: a method for analyzing cyclotriphosphazene flame retardants in environmental solid matrices based on LC-MS / MS technology, comprising, per 50mg of the sample to be detected, the method comprises the following steps:

[0022] Step (1) Pretreatment of the sample to be tested: The collected sample to be tested was sieved through a stainless steel screen (150 pm) and stored in a amber glass jar at a temperature of -20°C until analysis; 50 mg of the sample was weighed, 2 mL of a mixed solvent (acetonitrile: dichloromethane: methyl tert-butyl ether = 2:2:1; v:v:v) was added, vortexed for 10 min, ultrasonically extracted for 20 min, and centrifuged at 3600 r / min for 10 min, after which the supernatant was transferred to another centrifuge tube; the extraction was repeated twice, and the supernatants were combined; the solution was blown to near dryness under gentle nitrogen, 1 mL of acetonitrile was added, and filtered through a 0.22 pm filter membrane for instrument analysis;

[0023] Step (2) LC-MS / MS detection: an Exion LC AC ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (LC-MS / MS; AB Sciex, Framingham, MA) was used to analyze the sample in positive or negative mode of electrospray ionization (ESI), and the data were collected in multiple reaction monitoring (MRM) mode; an XBridge BEH C8 chromatographic column (100 mm x 2.1 mm, 2.5 pm, Waters) was used for sample separation, the sample amount was 5 pL, the flow rate was 0.25 mL / min, the column temperature was 40°C, and the mobile phase was (A) 5 mM ammonium acetate aqueous solution and (B) methanol;

[0024] In step (1), a 150 pm stainless steel screen was used to sieve the sample to be tested;

[0025] In step (1), the mixed extraction solvent was acetonitrile: dichloromethane: methyl tert-butyl ether = 2:2:1; v:v:v;

[0026] In step (1), the vortexing time was 10±2 min, the ultrasonic time was 20±2 min, and the centrifugation speed was 3600±200 rpm for 10±2 min;

[0027] In step (2), the detection conditions of the high performance liquid chromatography-triple quadrupole mass spectrometry instrument were as follows: Waters XBridge BEH C8 was selected as the liquid chromatography analysis column, the length of the liquid chromatography column was 100 mm, the inner diameter was 2.1 mm, and the filler particle diameter was 2.5 pm; positive or negative ionization electrospray (ESI) mode was used, the positive ion mode detection conditions were as follows: ion source spray voltage: 5500 V, ion source temperature: 550°C, spray gas: 45 psi, auxiliary heating gas: 45 psi, gas curtain gas: 35 psi, and collision gas: 7 psi; the negative ion mode detection conditions were as follows: ion source spray voltage: -4500 V, ion source temperature: 550°C, auxiliary heating gas: 45 psi, gas curtain gas: 35 psi, and collision gas: 7 psi.

[0028] PFPCTP, EPFCTP, HFCTP and HCCTP in step (2) were analyzed in negative ion mode, and HMCTP and HPCTP were analyzed in positive ion mode;

[0029] The mobile phase in step (2) was (A) 5 mM ammonium acetate aqueous solution and (B) methanol, and the gradient was: 0-1 min, 10% B; 1-2 min, 10-100% B; 2-8 min, 100% B; 8-9 min, 100-10% B; 9-14 min, 10% B.

[0030] Example 1: This example provides a method for analyzing cyclic phosphazene flame retardants in environmental solid matrix based on LC-MS / MS technology; the sample to be analyzed in this example is an indoor dust sample, and the method comprises the following steps:

[0031] House dust was collected from the floor and furniture surface of urban houses, and after being collected by a vacuum cleaner, it was transferred from a paper sampling bag to a clean aluminum foil; after being sieved through a stainless steel screen (150 μm), it was stored in an amber glass jar at a temperature of -20°C until analysis.

[0032] (1) Pretreatment method:

[0033] 50 mg of indoor dust sample was weighed into a glass centrifuge tube; then 2 mL of mixed extraction solvent (acetonitrile: dichloromethane: methyl tert-butyl ether = 2:2:1; v:v:v) was added, vortexed for 10 min, ultrasonicated for 20 min, and centrifuged at 3600 r / min for 10 min; the supernatant was transferred to another centrifuge tube, and the extraction was repeated twice, and the supernatants were combined. The supernatant was blown to near dryness under gentle nitrogen, 1 mL of acetonitrile was added and filtered through a 0.22 μm filter for instrument analysis;

[0034] (2) LC-MS / MS detection:

[0035] The specific detection conditions are that Waters XBridge BEH C8 is selected as a liquid chromatography analysis column, the length of the liquid chromatography column is 100 mm, the inner diameter is 2.1 mm, and the filler particle diameter is 2.5 μm; positive or negative ionization electrospray (ESI) mode is adopted, the positive ion mode detection conditions are that the ion source spray voltage is 5500 V, the ion source temperature is 550 DEG C, the spray gas is 45 psi, the auxiliary heating gas is 45 psi, the curtain gas is 35 psi, and the collision gas is 7 psi; the negative ion mode detection conditions are that the ion source spray voltage is -4500 V, the ion source temperature is 550 DEG C, the auxiliary heating gas is 45 psi, the curtain gas is 35 psi, and the collision gas is 7 psi; wherein, HMCTP and HPCTP are analyzed in the positive ion mode, and PFPCTP, EPFCTP, HFCTP and HCCTP are analyzed in the negative ion mode;

[0036] In the examples, a gradient elution program is adopted for elution, and the gradient elution program is specifically as follows:

[0037] Time 0-1 min: a mixed solution composed of methanol and 5 mM ammonium acetate aqueous solution with a volume ratio of 10:90 is used as the mobile phase, and the flow rate is 0.25 mL / min;

[0038] Time 1-2 min: the mixed solution composed of methanol and 5 mM ammonium acetate aqueous solution with a volume ratio of 10:90 is increased to 100:0 of methanol solution and 5 mM ammonium acetate aqueous solution as the mobile phase, and the flow rate is 0.25 mL / min;

[0039] Time 2-8 min: the mixed solution composed of methanol and 5 mM ammonium acetate aqueous solution with a volume ratio of 100:0 is used as the mobile phase, and the flow rate is 0.25 mL / min;

[0040] Time 8-9 min: the mixed solution composed of methanol and 5 mM ammonium acetate aqueous solution with a volume ratio of 100:0 is decreased to 10:90 as the mobile phase, and the flow rate is 0.25 mL / min;

[0041] Time 9-14 min: the mixed solution composed of methanol and 5 mM ammonium acetate aqueous solution with a volume ratio of 10:90 is used as the mobile phase, and the flow rate is 0.25 mL / min;

[0042] The analysis results obtained by detection are as follows, Figure 1 which is the total ion chromatogram of four kinds of cyclotriphosphazene flame retardants in the indoor dust sample in the negative ion mode based on the LC-MS / MS detection of the present application; Figure 2 which is the total ion chromatogram of two kinds of cyclotriphosphazene flame retardants in the indoor dust sample in the positive ion mode based on the LC-MS / MS detection of the present application;

[0043] Example 2

[0044] The embodiment provides a method for analyzing cyclotriphosphazene flame retardants in environmental solid matrix based on LC-MS / MS technology; the sample to be analyzed in the embodiment is a soil sample of urban roads in Guangzhou City, and the method comprises the following steps:

[0045] Soil samples are collected from different urban roads, and after collection, the samples are transferred to clean aluminum foil paper, dried at room temperature, ground, screened through a stainless steel screen (150 μm), finally sealed in a polypropylene self-sealing bag, and stored in a refrigerator at a temperature of -20 DEG C until analysis;

[0046] (1) Pretreatment method:

[0047] 50 mg of the soil sample is weighed in a glass centrifuge tube, 2 mL of mixed extraction solvent (acetonitrile: dichloromethane: methyl tert-butyl ether = 2:2:1; v:v:v) is added, vortexed for 10 min, ultrasonicated for 20 min, centrifuged at 3600 r / min for 10 min, the supernatant is transferred to another centrifuge tube, the extraction is repeated twice, and the supernatants are combined. The supernatant is blown to near dryness under mild nitrogen, 1 mL of acetonitrile is added and filtered through a 0.22 μm filter for instrument analysis;

[0048] (2) LC-MS / MS detection:

[0049] The specific detection conditions are as follows: Waters XBridge BEH C8 is selected as the liquid chromatography column, the length of the liquid chromatography column is 100 mm, the inner diameter is 2.1 mm, and the filler particle diameter is 2.5 μm; positive or negative ionization electrospray (ESI) mode is used, the positive ion mode detection conditions are as follows: ion source spray voltage: 5500 V, ion source temperature: 550 DEG C, spray gas: 45 psi, auxiliary heating gas: 45 psi, curtain gas: 35 psi, and collision gas: 7 psi; the negative ion mode detection conditions are as follows: ion source spray voltage: -4500 V, ion source temperature: 550 DEG C, auxiliary heating gas: 45 psi, curtain gas: 35 psi, and collision gas: 7 psi. Among them, HMCTP and HPCTP are analyzed in the positive ion mode, PFPCTP, EPFCTP, HFCTP and HCCTP are analyzed in the negative ion mode;

[0050] In the embodiment, a gradient elution program is used for elution, and the gradient elution program is specifically as follows:

[0051] Time 0-1 min: a mixed solution of methanol and 5 mM ammonium acetate aqueous solution with a volume ratio of 10:90 is used as the mobile phase, and the flow rate is 0.25 mL / min;

[0052] Time 1-2min: using the mixed solution composed of methanol and 5mM ammonium acetate aqueous solution with the volume ratio of 10:90 as the mobile phase, the volume ratio of methanol and 5mM ammonium acetate aqueous solution is increased to 100:0, the flow rate is 0.25mL / min;

[0053] Time 2-8min: using the mixed solution composed of methanol and 5mM ammonium acetate aqueous solution with the volume ratio of 100:0 as the mobile phase, the flow rate is 0.25mL / min;

[0054] Time 8-9min: using the mixed solution composed of methanol and 5mM ammonium acetate aqueous solution with the volume ratio of 100:0 as the mobile phase, the volume ratio of methanol and 5mM ammonium acetate aqueous solution is decreased to 10:90, the flow rate is 0.25mL / min;

[0055] Time 9-14min: using the mixed solution composed of methanol and 5mM ammonium acetate aqueous solution with the volume ratio of 10:90 as the mobile phase, the flow rate is 0.25mL / min;

[0056] The analysis results obtained by detection are as follows, Figure 3 It is the total ion chromatogram of the four cyclotriphosphazene flame retardants in the negative ion mode based on the LC-MS / MS detection of the soil samples beside the urban roads in the application; Figure 4 It is the total ion chromatogram of the two cyclotriphosphazene flame retardants in the positive ion mode based on the LC-MS / MS detection of the soil samples beside the urban roads in the application;

[0057] Table 1 is the chemical name, abbreviation and ion pair parameters of the six cyclotriphosphazene flame retardants;

[0058] Table 1

[0059]

[0060] Although the specific embodiments of the application have been described above, they are not intended to limit the protection scope of the application, and various modifications, replacements or deformations made by those skilled in the art on the basis of the technical solutions of the application without creative labor are still within the protection scope of the application.

[0061] It should be noted that, in this document, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0062] It should be pointed out finally that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for analyzing cyclic phosphazene flame retardants in environmental solid matrices based on LC-MS / MS technology, characterized by: The following steps are included per 50 mg of the sample to be tested: Step (1) Pretreatment of the sample to be tested: The collected sample to be tested is sieved through a stainless steel screen and stored in an amber glass jar at a temperature of -20°C until analysis; 50 mg of the sample is weighed, 2 ml of a mixed extraction solvent is added, vortexed for 10 min, ultrasonically extracted for 20 min, and centrifuged at 3600 r / min for 10 min, after which the supernatant is transferred to another centrifuge tube; the extraction is repeated twice, and the supernatants are combined; the solution is blown to near dryness under gentle nitrogen, 1 mL of acetonitrile is added, and the solution is filtered through a 0.22 μm filter membrane for instrument analysis; Step (2) LC-MS / MS detection: An ExionLC AC ultra-high performance liquid chromatography-triple quadrupole mass spectrometry instrument is used to analyze the sample in positive or negative mode under electrospray ionization, to detect PFPCTP, EPFCTP, HFCTP, HCCTP, HMCTP and HPCTP in the sample, PFPCTP, EPFCTP, HFCTP and HCCTP are analyzed in negative ion mode, and HMCTP and HPCTP are analyzed in positive ion mode, data is collected using multiple reaction monitoring mode; an XBridge BEH C8 chromatographic column is used for sample separation, the sample amount is 5 μL, the flow rate is 0.25 mL / min, the column temperature is 40°C, the mobile phase is A phase and B phase, the A phase is 5 mM ammonium acetate aqueous solution, the B phase is methanol, and the gradient is: 0-1 min, 10% B; 1-2 min, 10-100% B; 2-8 min, 100% B; 8-9 min, 100-10% B; 9-14 min, 10% B; In the step (1), the mixed extraction solvent is acetonitrile: dichloromethane: methyl tert-butyl ether = 2: 2: 1, v:v:v.

2. The method for analyzing cyclic phosphazene flame retardants in environmental solid matrix based on LC-MS / MS technology according to claim 1, characterized in that: In the step (1), a 150 μm stainless steel screen is used when the sample to be tested is sieved.

3. The method for analyzing cyclic phosphonitrilic flame retardants in environmental solid matrix based on LC-MS / MS technology according to claim 1, characterized in that: In the step (2), the detection conditions of the ExionLC AC ultra-high performance liquid chromatography-triple quadrupole mass spectrometry instrument are as follows: the length of the liquid chromatography column is 100 mm, the inner diameter is 2.1 mm, and the filler particle diameter is 2.5 μm; the positive ion mode detection conditions are: ion source spray voltage: 5500 V, ion source temperature: 550°C, spray gas: 45 psi, auxiliary heating gas: 45 psi, curtain gas: 35 psi, and collision gas: 7 psi; The negative ion mode detection conditions are: ion source spray voltage: -4500 V, ion source temperature: 550°C, auxiliary heating gas: 45 psi, curtain gas: 35 psi, and collision gas: 7 psi.

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