Gas chromatography - Mass spectrometrometration determines the content of triclosene in solvent-based coatings

A gas chromatography-mass spectrometrometrometrometrometrometrometrometrometrometrometrometrometrometrometrometrometrometrometration of three isomer (1,3,5-trichlorobenzene, 1,2,4-triclosene, 1,2,3-trichlorobenzene) in solvent-based coatings was established. Studyed the extraction and separation effect of trichlorobenzene from four solvents in coatings: acetone, positive hexane, tetrahydrofuran and ethyl acetate
gas chromatography-mass spectrometry to determine the content of triclosan in solvent-based coatings
Wei Yufeng, Wang Wenqing, Qiu Feng, Fei Xudong, Zhang Jidong (Shanghai Entry-Exit Inspection and Quarantine Bureau, Shanghai 200135)
Industrial Triclobene (Trichlorobene), TCBs) are generally a mixture of 3 isomers (1,3,5-tachlorobenzene, 1,2,4-tachlorobenzene, 1,2,3-tachlorobenzene) and are important chemical intermediates, widely used in coatings, dyes, pharmaceuticals, pesticides, additives and other fields, while triclosene is a class of chemically stable, widely contaminated and highly toxic compounds. According to the main use of triclosene in the industrial chain, the possibility of triclosene in coating products is very
in
. At present, the publicly reported literature mainly focuses on the detection of pclorobenzene in water and soil, there are also reports of PCB testing in dyes, the public reports on the detection methods of coating products have been positive butanol, perfluoroodine, hexabromode, aromatic compounds, 16 harmful substances, PCN, organotin and benzene and other substances testing, and solvent-based paint products in the detection of triclosan content has not been publicly reported. In this study, by using gas chromatography-mass spectrometrometrometrography technology to optimize the experimental conditions, the detection method of triclosene in solvent-based coating products was developed and established, which is simple to operate and has the characteristics of good reproducible and high precision.1 Test Part
1. 1 Instrument and Reagent
Gas Chromatography-Mass Spectrometry Joint Instrument (6890N-5975), with EI source detector, Ailent Corporation of the United States.
ethyl acetate, tetrahydrofuran: HPLC grade, CNW, Germany; 1,3,5-trichlorobenzene (>99.0%): TCI, Japan; 1,2,4-trichlorobenzene (99%): J.K. SCIENTIFIC, United States; 1,2,3-trichlorobenzene (99%): ALDRICH Corporation of the United States.
1. 2 Experimental conditions
1. 2. 1 Chromatography Conditions
(1) Columns: HP - 5 ms, Capillary columns 30.0 m ×0. 25 mm (I. D. ×0. 25 sm;
(2) column program heating conditions: the initial column temperature of 100 degrees C, maintain 2 min, at a rate of 10 degrees C / min to 180 degrees C, and then at a rate of 50 degrees C / min to 280 degrees C to maintain 10 min;
(3) sample port temperature: 300 degrees C;
(4) carrier: helium, purity ≥99.999%; flow rate 0.5 mL/min;
(5) sample mode: selow mode, sification ratio 150:1;
(6) intake: 1 μL.
1. 2. 2 Mass spectrometrometer conditions
(1) electron bombardment ionization source (EI), electron energy: 70 eV;
(2) ion source temperature: 230 degrees C, four pole temperature: 150 degrees C;
(3) solvent delay time: 3. 00 min;
(4) Mass scan mode (full scan mode), scan range (m/z): 30 to 250;
(5) Mass scan mode (SIM scan mode), SIM monitoring ion (m/z): 74. 0, 109. 0, 145. 0, 180. 0;
(6) quantitative ions (m/z): 180. 0.
1. 3 Standard solution preparation
1. 3. 1 Triclosan Standard Reserve Solution
1,3,5-triclosan, 1,2,4-TCB and 1,2,3-triclosan Standard Substances 0. In bottles of 2 g (accurate to 0.1 mg) to 100 mL, ethyl acetate is used to make standard reserve fluids of 1,3,5-triclosene, 1,2,4-4-triclosene and 1,2,3-triclosene at concentrations of 2,000 mg/L. The standard reserve solution is stored in a refrigerator at 0 to 4 degrees C.
1. 3. 2 Standard working solution
Take the appropriate amount of tcblorobenzene standard reserve liquid (1. 3. 1), dilute with ethyl acetate solvent to a mass concentration of 1 mg/L, 5 mg/L, 10 mg/L, 20 mg/L, 50 mg/L, 100 mg/L standard working solution, when used.
1. 4 Standard curve drawing
In accordance with the measurement conditions listed in 1. 2, set the selection SIM ion scanning
mode (m/z=74.0, 109.0, 145. 0, 180. 0), the standard work
solution (1. 3. 2) in turn sample determination, in the resulting spectra extracted a fixed amount of ions
(m/ z s 180.0) to obtain the ion peak
area, and its horizontal
coordinates;
1. 5 Analysis Methods
1. 5. 1 Qualitative Analysis
1. 3. 1 A standard triclosbenzene reserve solution diluted with ethyl acetate to a certain concentration of standard triclosbenzene solution, using automatic Sampler, injection gas chromatography- mass spectrometry combinator, full scan mode analysis, get the total ion flow map of the target compound, according to the 3 target compounds, get the retention time, determine the retention time of the target compound in the total ion flow map;
set to select the ion scanning mode (m/z s 74. 0, 109. 0, 145. 0, 180. 0) to analyze the standard solution, extract quantitative ions (m/z=180.0) in the resulting spectral map to obtain the extracted ion chromatography of triclosene in the standard solution, see Figure 1.
1. 5. 2 Quantitative analysis of triclosan in paint samples
After mixing and mixing the paint samples evenly, it is said that 1 g (accurate to 0.1 mg), with 10 mL ethyl acetate diluted, after the solution is fully mixed and uniform, after the organic filter membrane filtration, autosorbent gas chromatography-mass spectrometry, with 1. 2 experimental conditions to select ion scanning mode for analysis.2 Results and Discussion
2. 1 Options for Extracting Solvents
examined the extraction and separation effects of four organic solvents: acetone, positive hexane, tethydrofuran and ethyl acetate. The experimental results show that: Acetone as a solvent, due to the high volatility of the solvent, resulting in poor test repeatability, tethydrofuran and erthylhexane as a solvent, the solvent background of more impurities, treatment of the compound interference; Therefore, the experiment selected ethyl acetate as the extraction solvent.
2. 2 pre-treatment method selection
this experiment with ethyl acetate solvent with different dilution multiplication dilution paint samples, analysis. The results show that the appropriate sample size and solvent dilution volume have an important influence on the sample test results. If the solvent dilution ratio is too low, the sample is viscous, easy to lead to sample difficulties, and easy to stick the sample needle, so that the experiment is terminated or damaged the sample needle, and the extraction solvent volume is too large, the dilution multiply is too large, it is easy to lead to the paint triclosene response is too small, not conducive to accurate quantitative analysis. This experiment optimizes the extraction method: after mixing and mixing the paint sample well, take 1 g (accurate to 0. 1 mg), add 10 mL ethyl acetate, seal the sample bottle and mix with ultrasound. After the solution is fully mixed, it is filtered by an organic filter film and sampled. The results show that the optimized extraction method greatly reduces the number of needles and can meet the detection limit requirements of the method. In addition, due to the variety of coating products, sample viscosity and other physical properties vary greatly, for different coatings, take different solution mixing methods. For turbid coatings with more particulate suspended matter, centrifugal operation of solvent-diluted solution is required, centrifugation of 5 min at the speed of 5,000 r/min, after sit-in, the upper liquid is filtered and sampled; Products, the solvent diluted solution needs to be violent oscillation, and ultrasonic mixing, static after filtration after sample, for clarified, small viscosity paint products, diluted by solvent, after moderate oscillation mixing, after static after filtration into the sample.
2. The linear equation of the 3 method and the detection limit
according to the standard working solution of the different concentrations of the preparation, the calibration curve of three kinds of triclosene is drawn, and the corresponding linear equations, correlation coefficients and linear ranges are drawn. As shown in Table 2, the object to be measured has a good linear relationship with its selected ion peak area in the range of 1 to 100 mg/L mass concentration, with a wide linear range.
select a paint sample containing 0.001% (mass score, same below), called 1 g dilution to 10 mL, fully mixed and filtered by organic filter membrane sample analysis, repeated test 6 times, according to the signal-to-noise ratio S/N-3 calculation of the method's detection limit (mg/kg), according to the signal-to-noise ratio S/N-10 calculation of the method quantitative limit (mg/kg), see table 2.
2. 4 Recovery rate and precision experiment
selected 2 paint samples that do not contain triclosene, added a certain concentration of triclosene standard substances, according to the established method of application of GC-MS analysis, calculate the recovery rate.
2. 4. 1 Sample plus standard solution preparation
added 0.1%, 0.05%, 0.025% of the standard triclosbenzene substances to the paint sample, respectively, after full oscillation, ultrasonic mixing, sit still for testing.
2. 4. 2 Diluted sample
accurately named 1 g (accurate to 0.1 mg) labeled sample, diluted with ethyl acetate to 10 mL, and fully mixed, after static after filtering by the filter membrane into the chromatography-mass spectrometry, using the established analytical method for quantitative analysis.
4. 3 Results Analysis
the recovery rate of triclosene in paint samples is in Table 3.
: (1) - relative to the standard deviation, the same between the following.
table 3 shows that the average recovery rate of 1,3,5-triclosene was between 95.9% and 106.0% among the three levels of addition, and the average recovery rate of 1,2,4-triclosene was 96. Between 7% and 105.3%, the average recovery rate of 1,2,3-triclosene was between 97.3% and 107.6%, all maintained a good recovery rate, and the relative standard deviation was between 1.44% and 4.33%, proving that the method was used to detect the accuracy of triclosene in paint samples.
2. 5 Determination of actual samples
the presence of triclosene was detected in a brand of varnish sample using the above qualitative analysis method. Quantitative analysis: accurately weigh 1 g (accurate to 0. 1 mg) varnish sample, diluted with ethyl acetate to 10 mL, and fully mixed, after static after filtering by the filter film into the air chromatography- mass spectrometry instrument, select the ion scanning mode (m / z - 74. 0、109. 0、145. 0、180. 0) Analysis to extract quantitative ions in the resulting graph (m/z s 180. 0) The peak area of 3 target compounds is obtained, the working curve is established, and the content of 3 target compounds is obtained, as in Table 4.
from Table 4, it can be seen that the parallelity of the test is better with this method, and the relative standard deviation of the test results is <5%.
xylorobenzene selection ion chromatography (m/z s 74. 0, 109. 0, 145. 0, 180. 0) See figure
1,2,3 compounds identified in figures 1,2,3, 3, 1,3,5-triclosene, 1,2,4-triclosene, 1,2,3-triclosene, depending on the retention time of the target compound and the qualitative ions. Extract quantitative ions in Figure 2 (m/z-180. 0) The peak area of 3 target compounds is obtained, and the content of 3 compounds is calculated according to the working curve.3 Conclusion
According to the application of triclosene in the industrial chain, there is a high probability that triclosene substances will remain in coating products, and the presence of triclosene in paint products is harmful to human health and environmental safety. A gas chromatography-mass spectrometrometrometrometrometrometrometrometrometrometrometromety of 3 kinds of triclosene isomer in coating products is established, which has a wide linear range, low detection limit, and has strong anti-jamming ability and high sensitivity, which can be used as a means of detection of triclosene content in solvent-based coating products.