A method for determining dimethyl [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonate in cotton fabric

Abstract

The invention discloses a method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric, and belongs to the technical field of analytical chemistry. The method comprises the following steps: weighing a cotton fabric sample to be tested, cutting it into pieces, adding methanol thereto, and obtaining an extract after ultrasonic treatment, and filtering the extract to obtain a solution to be tested; diluting a target standard stock solution step by step with methanol to obtain a standard working solution of a series of concentrations, and performing liquid chromatography-tandem mass spectrometry on the standard working solution of the series of concentrations, and drawing a standard working curve with the concentration as the horizontal coordinate X and the peak area as the vertical coordinate Y; performing liquid chromatography-tandem mass spectrometry on the obtained solution to be tested under the same determination conditions, and comparing the obtained peak area with the standard curve to calculate the content of the target in the cotton fabric sample. The analytical test method has a low detection limit, good precision, and a high sample spike recovery rate, and meets the test requirements of the target compound.

Description

Technical Field

[0001] The invention belongs to the technical field of analytical chemistry, and in particular relates to a method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric. Background Art

[0002] Since organophosphorus flame retardants are added to products in a non-chemical bond manner, they can easily spread into the surrounding environment. Studies have shown that organophosphorus flame retardants have been detected in water, air, sediment, dust, and organisms. Since organophosphorus flame retardants are commonly detected in the environment and organisms, and many compounds have carcinogenicity, neurotoxicity, and reproductive toxicity, posing a potential threat to the ecological environment and human health, they have become a research hotspot internationally.

[0003] [3-[(Hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester (3-(Dimethylphosphono)-N-methylolpropionamide), the molecular formula is C6H 14 NO5P, CAS No.20120-33-6, molecular weight is 211.15. [3-[(Hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester (flame retardant FRC-2) is often added to cotton fabrics as a flame retardant. At present, the research on [3-[(Hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester mainly focuses on the synthesis and application fields, and there are few reports on the detection of its content in cotton fabrics. Therefore, it is urgent to develop an accurate, efficient, convenient and fast detection method to detect this substance, so as to lay a foundation for the safety research of flame retardant [3-[(Hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester.

[0004] Current research mainly focuses on the detection of phenyl phosphate or simple short-chain hydrocarbon phosphate flame retardants, and no detection method for the flame retardant FRC-2 ([3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester) has been reported. Summary of the invention

[0005] To solve the related problems, the primary purpose of the present invention is to provide a method for determining dimethyl [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonate in cotton fabrics. The method is simple, rapid, accurate and sensitive, and can provide technical support for the safety assessment of cotton fabrics in terms of detection and analysis.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0007] A method for determining dimethyl [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonate in cotton fabric comprises the following steps:

[0008] (1) Sample pretreatment

[0009] Weigh the cotton fabric sample to be tested, cut it into pieces, add methanol to it, and obtain an extract after ultrasonic treatment. After filtering the extract, it is the solution to be tested;

[0010] (2) Establishment of standard curve

[0011] a. Prepare standard working solution: dilute the standard stock solution of [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester stepwise with methanol to obtain a series of standard working solutions;

[0012] b. Liquid chromatography-tandem mass spectrometry: Liquid chromatography-tandem mass spectrometry was performed on the standard working solutions of a series of concentrations. The measurement conditions were as follows:

[0013] Liquid chromatography conditions: chromatographic column: Agilent Eclipse XDB-C18, 2.1*100mm, 3.5μm; column temperature: 30-40°C; injection volume: 1-2μL; flow rate: 0.2-0.5mL / min; mobile phase: mobile phase A is 0.01%-0.5% by volume formic acid aqueous solution or acetic acid aqueous solution, mobile phase B is acetonitrile; elution mode: isocratic elution, mobile phase A is 10-50%, mobile phase B is 40-90%;

[0014] Mass spectrometry conditions: under the condition of electrospray ion source positive ion mode (ESI+), select multiple reaction monitoring (MRM) mode, capillary voltage: 4000V, electrospray voltage: 45psi, sheath gas temperature: 300-350℃; sheath gas flow rate: 8-15L / min; drying gas temperature: 300-330℃; drying gas flow rate 4L / min-8L / min, declustering voltage: 100-150V; collision energy: 6-25eV; parent ion (m / z): 165, daughter ion (m / z): 136.9, 109, 79;

[0015] c. Draw the standard curve: Draw the standard working curve with the concentration as the horizontal coordinate X and the peak area as the vertical coordinate Y; the linear equation of the obtained standard curve is: Y = 93.9037X + 27.389, and the correlation coefficient is r 2 =0.9999, LOD=0.0744μg / L, LOQ=0.2480μg / L;

[0016] (3) Determination of [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in the test solution

[0017] The solution to be tested obtained in step (1) is subjected to liquid chromatography-tandem mass spectrometry under the determination conditions in step (2), and the obtained peak area is substituted into the standard curve to calculate the content of [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in the cotton fabric sample.

[0018] Furthermore, the ratio of the cotton fabric sample to methanol in step (1) is 1 g: 10-50 mL.

[0019] Furthermore, the ratio of the cotton fabric sample to methanol in step (1) is 1 g:10 mL.

[0020] Furthermore, the ultrasonic conditions in step (1) are as follows: temperature 25-60°C and time 30-90 min.

[0021] Furthermore, the ultrasonic conditions in step (1) are: temperature 25° C., time 60 min.

[0022] Furthermore, the shredding in step (1) refers to shredding into pieces of 2±1 mm×2±1 mm×2±1 mm.

[0023] Furthermore, the filtration described in step (1) refers to filtering through a 0.22 μm filter membrane.

[0024] Furthermore, the concentrations of the series of standard working solutions described in step (2) are 0.5 μg / L, 1.0 μg / L, 2.0 μg / L, 5.0 μg / L, and 10.0 μg / L, respectively.

[0025] Furthermore, the liquid chromatography conditions described in step (2) are as follows: the chromatographic column is Agilent Eclipse XDB-C18, 2.1*100mm, 3.5μm; column temperature: 40°C; injection volume: 1μL; flow rate: 0.2mL / min; mobile phase: mobile phase A is a 0.1% by volume formic acid aqueous solution, and mobile phase B is acetonitrile; elution mode: isocratic elution, mobile phase A is 15%, and mobile phase B is 85%.

[0026] Furthermore, the mass spectrometry conditions described in step (2) are as follows: under the electrospray ion source positive ion mode, the multiple reaction monitoring mode is selected, the capillary voltage is 4000V, the electrospray voltage is 45psi, the sheath gas temperature is 350°C; the sheath gas flow rate is 11L / min; the drying gas temperature is 330°C; the drying gas flow rate is 5L / min, the declustering voltage is 112V; the parent ion (m / z): 165, the daughter ions (m / z): 136.9, 109, 79.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] (1) The present invention establishes a method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric by liquid chromatography-tandem mass spectrometry.

[0029] (2) By optimizing the instrument analysis parameters, the target compound [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester] can obtain a symmetrical chromatographic peak within 2 minutes. The use of volatile acid solution as the mobile phase improves the positive ionization efficiency and greatly improves the response value of the compound.

[0030] (3) The analytical test method has a low detection limit, good precision, and high sample spike recovery, meeting the test requirements of the target compound. The target compound showed a good linear relationship in the range of 0.5 to 10.0 μg / L (r 2 >0.9999); the detection limit and quantitative limit are both low; in the precision test, the relative standard deviation is <2.2%; in the accuracy test, the sample spike recovery rate is 95.1%~102.9%. This method has high accuracy and can meet the test requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The total ion current (TIC) and multiple reaction monitoring (MRM) chromatograms are shown under the condition that the mobile phase A is 15% formic acid (concentration is 0.1%);

[0032] Figure 2 TIC chromatogram and MRM chromatogram of the spiked blank sample;

[0033] Figure 3 It is the standard working curve diagram;

[0034] Figure 4 The TIC chromatograms corresponding to aqueous formic acid solutions with different concentrations;

[0035] Figure 5 It is the average recovery curve of different extraction temperatures;

[0036] Figure 6 The average recovery curve of different extraction times. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with examples and drawings, but the embodiments of the present invention are not limited thereto.

[0038] Example 1

[0039] 1. Preparation of standard solution

[0040] Standard stock solution: Use a 100,000 grade analytical balance to accurately weigh 10 mg of [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester standard, dissolve it in methanol and make up to volume in a 10 mL volumetric flask to obtain a 1000 mg / L stock solution of the standard substance, and store it in a refrigerator at 4°C away from light.

[0041] Standard working solution: Dilute the standard stock solution stepwise with methanol to obtain a series of mixed standard working solutions of 0.5 μg / L, 1.0 μg / L, 2.0 μg / L, 5.0 μg / L, and 10.0 μg / L.

[0042] 2. Instrument method conditions

[0043] Liquid chromatography conditions:

[0044] Agilent Eclipse XDB-C18, 2.1*100mm, 3.5μm; column temperature: 40℃; injection volume: 1μL; flow rate: 0.2mL / min; mobile phase A is 0.1% (volume fraction) formic acid aqueous solution; mobile phase B is acetonitrile; elution mode: isocratic elution, mobile phase A is 15%, mobile phase B is 85%.

[0045] Mass spectrometry conditions:

[0046] Under the conditions of electrospray ion source positive ion mode (ESI+), multiple reaction monitoring (MRM) mode was selected, capillary voltage: 4000V, electrospray voltage: 45psi, sheath gas temperature: 350℃; sheath gas flow rate: 11L / min; drying gas temperature: 330℃; drying gas flow rate: 5L / min, declustering voltage: 112V; parent ion (m / z): 165, daughter ions (m / z): 136.9, 109, 79.

[0047] Figure 1 These are the TIC and MRM chromatograms when the mobile phase A is 15% formic acid (volume fraction is 0.1%).

[0048] 3. Linear equation and detection limit analysis

[0049] Under the above conditions, the linear range and minimum detection limit test of the target compound [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester were determined. The standard stock solution was diluted with methanol step by step to a series of mixed standard working solutions of 0.5μg / L, 1.0μg / L, 2.0μg / L, 5.0μg / L, and 10.0μg / L. The standard working curve was drawn with mass concentration X (μg / L) as the horizontal axis and peak area Y as the vertical axis. The linear regression equation and other parameters of the analyte are shown in Tables 1 and Figure 2From the data in the table and the figure, it can be seen that within the linear range of 0.5μg / L to 10.0μg / L, the flame retardant FRC-2 shows a good linear relationship, and its detection limit and quantification limit are both low.

[0050] Table 1. Regression equation and other parameters of flame retardant FRC-2

[0051]

[0052] 3. Precision and accuracy analysis

[0053] Table 2. Precision and accuracy test results

[0054]

[0055] As shown in Table 2 and Figure 3 As shown in the figure, three different spike concentration levels (0.5μg / L, 2.0μg / L, 10.0μg / L) were measured six times, and the relative standard deviation was <2.2%, indicating that the test method has good repeatability and high precision. At the three spike levels, the spike recovery of the target substance was in the range of 95.1% to 102.9%, indicating that the method has high accuracy and can meet the test requirements.

[0056] 4. Sample pretreatment:

[0057] Weigh 1 g of cotton fabric sample (accurate to 0.1 mg), cut it into pieces of 2 mm × 2 mm × 2 mm, put it in a sample bottle, add 10 mL of methanol, tighten the bottle cap and put the sample into an ultrasonic cleaner at 25 ° C for 60 min. Take 1 mL of the extract and filter it through a 0.22 μm filter membrane before directly measuring it.

[0058] 5. Measurement results:

[0059] The content of [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in the cotton fabric sample was calculated by comparing with the standard curve, and the result was 0.2015 mg / kg.

[0060] Comparative Example 1: Response values ​​of the target substance under different concentrations of formic acid aqueous solution (different mobile phases)

[0061] The other experimental conditions were controlled to be consistent with those in Example 1, except that in the liquid chromatography conditions, the concentration of the formic acid aqueous solution was 0.01% or 0.05%.

[0062] The TIC chromatograms corresponding to different concentrations of formic acid aqueous solutions are shown in Figure 2 ,The results show that within a certain concentration range, the response value of the target compound is higher at the formic acid concentration of the present invention.

[0063] Comparative Example 2: Recovery rate of target compound at different extraction temperatures

[0064] The other experimental conditions were controlled to be consistent with those in Example 1, except that the extraction temperature in the sample pretreatment was 45° C. or 60° C.

[0065] like Figure 3 As shown, the results show that when the extraction temperature is 25°C, the average recovery rate of [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester is the highest, higher than 95%; when the temperature is raised to 60°C, the recovery rate drops sharply, and the average recovery rate is close to 80%.

[0066] Comparative Example 3: Recovery rate of target compound at different extraction times

[0067] The other experimental conditions were controlled to be the same as those in Example 1, except that the extraction time in sample pretreatment was 80 min or 100 min.

[0068] like Figure 4 As shown in the figure, the results showed that when the extraction time increased from 60 min to 80 min and 100 min, the recovery rate of the target compound decreased.

[0069] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the described embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. A method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric, characterized in that: The following steps are involved: (1) Sample pretreatment Weigh the cotton fabric sample to be tested, cut it into pieces, add methanol to it, and obtain the extract after ultrasonic treatment. After filtering the extract, it is the solution to be tested. The ultrasonic conditions are: temperature 25℃, time 60 min; (2) Establishment of standard curve a. Prepare standard working solution: dilute the [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester standard stock solution stepwise with methanol to obtain a series of concentration standard working solutions; b. Liquid chromatography-tandem mass spectrometry: Liquid chromatography-tandem mass spectrometry was performed on the standard working solutions of a series of concentrations. The measurement conditions were as follows: Liquid chromatography conditions: chromatographic column: Agilent Eclipse XDB-C18, 2.1*100mm, 3.5μm; column temperature: 30-40℃; injection volume: 1-2 μL; flow rate: 0.2-0.5mL / min; mobile phase: mobile phase A is 0.01%-0.5% formic acid aqueous solution or acetic acid aqueous solution, mobile phase B is acetonitrile; elution mode: isocratic elution, mobile phase A is 15%, mobile phase B is 85%; Mass spectrometry conditions: in the electrospray ion source positive ion mode, select the multiple reaction monitoring mode, capillary voltage: 4000V, electrospray voltage: 45 psi, sheath gas temperature: 300-350℃; sheath gas flow rate: 8-15 L / min; drying gas temperature: 300-330℃; drying gas flow rate 4 L / min-8 L / min, declustering voltage: 100-150 V; collision energy: 6-25 eV; parent ion: 165, daughter ions: 136.9, 109, 79; c. Draw the standard curve: Draw the standard working curve with concentration as the horizontal axis X and peak area as the vertical axis Y; the linear equation of the obtained standard curve is:, the correlation coefficient r 2 =0.9999, LOD=0.0744μg / L, LOQ=0.2480μg / L; (3) Determination of [3-[(Hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in the test solution The solution to be tested obtained in step (1) is subjected to liquid chromatography-tandem mass spectrometry under the determination conditions in step (2), and the obtained peak area is substituted into the standard curve to calculate the content of [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in the cotton fabric sample.

2. The method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric according to claim 1, characterized in that: The liquid chromatography conditions described in step (2) are as follows: chromatographic column: Agilent Eclipse XDB-C18, 2.1*100mm, 3.5μm; column temperature: 40°C; injection volume: 1μL; flow rate: 0.2mL / min; mobile phase: mobile phase A is 0.1% by volume formic acid aqueous solution, mobile phase B is acetonitrile; elution mode: isocratic elution, mobile phase A is 15%, mobile phase B is 85%.

3. The method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric according to claim 1 or 2, characterized in that: The mass spectrometry conditions described in step (2) are as follows: under the electrospray ion source positive ion mode, select the multiple reaction monitoring mode, capillary voltage: 4000V, electrospray voltage: 45 psi, sheath gas temperature: 350°C; sheath gas flow rate: 11 L / min; drying gas temperature: 330°C; drying gas flow rate: 5 L / min, declustering voltage: 112 V; parent ion: 165, daughter ions: 136.9, 109, 79.

4. The method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric according to claim 3, characterized in that: The ratio of the cotton fabric sample to methanol in step (1) is 1 g: 10-50 mL.

5. The method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-dimethyl phosphonate in cotton fabric according to claim 4, characterized in that: The ratio of the cotton fabric sample to methanol in step (1) is 1 g:10 mL.

6. The method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric according to claim 3, characterized in that: The cutting into pieces in step (1) refers to cutting into pieces of 2±1 mm×2±1 mm×2±1 mm.

7. The method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric according to claim 3, characterized in that: The filtration described in step (1) refers to filtration through a 0.22 μm filter membrane.

8. The method for determining [3-[(hydroxymethyl)amino]-3-carbonylpropyl]-phosphonic acid dimethyl ester in cotton fabric according to claim 3, characterized in that: The concentrations of the series of standard working solutions described in step (2) are 0.5 μg / L, 1.0 μg / L, 2.0 μg / L, 5.0 μg / L, and 10.0 μg / L, respectively.

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