CN103728405B - The research method of timber preservative Transport in a kind of Wood children articles for use - Google Patents

Abstract

The invention discloses a method for researching the migration law of wood preservatives in wooden children's products. (2) Determination of the migration amount of each preservative in the sample: add the migration solution to the sample, add the internal standard working solution, and use the gas chromatography-tandem mass spectrometry detection method to determine; (3) based on the migration of the sample Determination of the total content and migration of each preservative, and analysis of the results obtained under different experimental simulation conditions, to obtain the maximum migration rate and migration law of wood preservatives in wooden children's products. The research method of the present invention has more theoretical basis for the experimental design of the migration law of 10 kinds of wood preservatives, is more conducive to the production of positive standard samples, and ensures that the research results of the migration law are more accurate and reliable.

Description

A research method for the migration of wood preservatives in wooden children's products

technical field

The invention relates to a research method for the migration law of preservatives in wood, in particular to a research method for the migration laws of wood preservatives in wooden children's products.

Background technique

Common wooden children's products on the market include wooden toys, cribs and so on. Due to reports of toxic toy coating incidents, many manufacturers currently claim that their products are "logs" and "non-toxic paint", giving consumers an impression of environmental protection and non-toxicity. However, the possible presence of wood preservatives in them Hazards are often overlooked. In order to avoid cracking and mold due to moisture, logs and finished products are generally treated with anti-corrosion treatment. Taking wooden toys as an example, infants under the age of 3 often bite or lick with their mouths when playing with them, or soak the toys in water, so that the wood preservatives will migrate to the baby with saliva, sweat, or water. In the body of young children, it will cause harm to it. Substances such as polychlorinated phenols and pyrethroids may cause teratogenicity, carcinogenicity and gene mutation. In the harmonized standards EN71-9, 10, and 11 published by the European Union, the 10 kinds of wood preservatives involved in this article have limited requirements, and the minimum limit is 1mg/kg.

For the research on the migration law of wood preservatives, there is very little work carried out at home and abroad at present. The information that can be found only involves water-borne preservatives such as CCA and pentachlorophenol, and the main samples are soil and groundwater. Researchers at home and abroad have reported on the migration behavior of plasticizers, bisphenols, aromatic amines, and ultraviolet absorbers in food packaging materials such as plastics. Some research results cannot be directly applied.

Compared with the migration rules, there are relatively more reports on the detection methods of polychlorinated phenols and pyrethroids, mainly for food and environmental samples. Due to the complex composition of wood samples, only chromatography or chromatography-single-stage mass spectrometry may not provide sufficient selectivity and sensitivity, while tandem mass spectrometry has the characteristics of high selectivity and high sensitivity, and can detect trace amounts in complex Confirmatory analysis of substances is more suitable as a detection technique for studying the migration of substances.

Contents of the invention

The technical problem to be solved by the present invention is to provide an easy-to-operate, accurate and reliable research method for the migration law of wood preservatives in wooden children's products.

A method for researching the migration law of wood preservatives in wooden children's products, comprising the steps of:

(1) By self-made positive standard samples containing 10 wood preservatives, the actual total content of each preservative in the sample was determined by gas chromatography-tandem mass spectrometry;

(2) Determination of the migration amount of each preservative in the positive sample: Use a low-speed cutting machine to cut the surface layer of the wood sample with a thickness of 3mm, grind it into sawdust less than 2mm by a grinder, accurately weigh 2g of the sample into a 50mL stoppered test tube, and add the migration solvent 40mL, the migration solvent is simulated saliva, simulated sweat or water, oscillated in a water bath at 37°C and 100r/min for 1-10h, and passed through a 200μm stainless steel filter to obtain a migration solution; add 1mL internal standard to the migration solution For the working solution, adjust the pH value to 6, add 1mL acetic anhydride for derivatization, operate for about 1min, place on a shaker and shake for 10min; pass the derivatized solution through Oasis HLB activated in advance with 5mL methanol and equilibrated with 5mL deionized water The solid-phase extraction column was rinsed with 5mL deionized water, drained with a vacuum pump, and finally eluted with 10mL ethyl acetate. The eluate was collected and dried by adding an appropriate amount of anhydrous sodium sulfate. After vortexing for 30s, the gas chromatography-tandem Determination by mass spectrometry detection method;

(3) According to the characteristics of the use of wooden children's products, by setting different experimental simulation conditions, based on the determination of the total content and migration amount of each preservative in the sample, the results obtained are summarized and analyzed, and the wooden The maximum migration rate and migration law of each wood preservative in children's products.

The method for researching the migration law of wood preservatives in wooden children's products according to the present invention, wherein the method measures the total content and migration amount of 10 kinds of preservative substances in the sample at the same time, and conducts research on the migration law through experimental simulation conditions. The preservatives are 2,4 dichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, lindane, pentachlorophenol, cypermethrin , cyfluthrin, permethrin and deltamethrin.

The method for researching the migration law of wood preservatives in wooden children's products according to the present invention, wherein step (3) specifically includes the following steps: for polychlorinated phenols, prepare 5 mg/kg and 10 mg/kg positive standard samples, and for chrysanthemum Prepare 50mg/kg and 100mg/kg positive samples of ester substances, migrate in different migration solvents for 1-10h respectively, set the water bath temperature at 37°C, take samples to measure the migration amount of each substance under simulated experimental conditions, and summarize the results as Figure, intuitively analyze the migration behavior; by measuring the actual total content of the 10 substances in all positive samples, calculate the ratio of the migration value to the corresponding total value, that is, the mobility of each substance within 10h, where each The maximum value of the migration rate of the substance within 10 hours is the maximum migration rate. By comparing the maximum migration rate of each substance in different migration solvents in positive samples with different contents, and comparing with the previous results, 10 kinds of wood preservatives are finally obtained. Agent migration rules.

The method for researching the migration law of wood preservatives in wooden children's products of the present invention also includes the preparation of positive samples, including the following steps: using a grinder to crush a blank wood sample into wood chips less than 2 mm, and weighing an appropriate amount of wood chips in a tool Plug the round bottom flask, add the fully mixed standard solution in an Erlenmeyer flask, and add methanol to dilute to ensure that the diluted solution can be poured into the round bottom flask to immerse all the sawdust; place the round bottom flask on a shaker for 2 hours After standing overnight, ensure that the preservative fully penetrates into the wood, and then rotate steam at 35°C and 170hPa. During the rotary steaming process, the pressure gradually transitions from 300hPa to 170hPa, slowly evaporate the solvent to nearly dry, and spread the nearly dry wood chip samples On a large surface dish, until the solvent is completely evaporated, a positive sample is obtained.

The method for researching the migration of wood preservatives in wooden children's products according to the present invention, wherein the internal standard working solution is prepared by the following method: Weigh 50mg of 2,3,4-trichlorophenol in a 100mL brown volumetric flask , dilute to volume with ethanol/glacial acetic acid solution with a volume ratio of 9:1, prepare a 500 mg/L internal standard stock solution, and then dilute it to a concentration of 5 mg/L internal standard working solution.

The research method of the migration law of wood preservatives in wooden children's products according to the present invention, wherein the preparation method of the simulated saliva is prepared by the following method: respectively weigh 4.5g of sodium chloride, 0.3g of potassium chloride, sulfuric acid Sodium 0.3g, ammonium chloride 0.4g, 90% lactic acid 3.0g, urea 0.2g, mix and dilute to 1000mL with deionized water, pH≈3;

The simulated sweat is prepared by the following method: Weigh 4.2g of sodium bicarbonate, 0.5g of sodium chloride, and 0.2g of potassium carbonate, mix them and dilute to 1000mL with deionized water, pH≈8.8.

The method for researching the migration law of wood preservatives in wooden children's products according to the present invention, wherein step (1) specifically includes the following steps: crush the sample to sawdust less than 2 mm, accurately weigh 2 g, and ultrasonically extract 2 times with methanol, each 20 mL at a time, extract for 15 min, filter and combine the filtrate into a centrifuge tube, add 1 mL of internal standard working solution, centrifuge at 4 °C and 13000 r/min for 5 min, filter through a 0.45 μm PTFE filter membrane, transfer to a chicken heart bottle, and store at 35 °C , Concentrate to 2mL by rotary evaporation at 170hpa, add 40mL0.1mol/L potassium carbonate solution to the concentrated solution, shake well, add 1mL acetic anhydride for derivatization, deflate while shaking, operate for about 1min, then place on a shaker for 10min , pass the derivatized solution through the Oasis HLB solid-phase extraction column activated by 5mL methanol and equilibrated with 5mL deionized water in advance, rinse with 5mL deionized water, use a vacuum pump to dry the water, and finally elute with 10mL ethyl acetate , collect the eluent, add appropriate amount of anhydrous sodium sulfate to dry, vortex for 30s, and then use gas chromatography-tandem mass spectrometry detection method for detection.

The method for researching the migration law of wood preservatives in wooden children's products according to the present invention, wherein the chromatography-mass spectrometry condition of the gas chromatography-tandem mass spectrometry detection method is: Agilent HP-5MS chromatographic column, the specification is 30m×0.25mm i.d. , 0.25μm; inlet temperature 280℃; carrier gas flow rate 1.0mL/min; Rise to 280°C at 10°C/min and hold for 8min; solvent delay for 5min; transfer line temperature 250°C; ion source temperature 180°C; EI ionization mode, ionization energy 70eV, MRM mode measurement.

The difference between the research method of the wood preservative migration law in the wooden children's products of the present invention and the prior art is:

The method is based on the solid-phase extraction-gas chromatography-tandem mass spectrometry (SPE-GC-MS/MS) detection technology of 10 wood preservatives in wooden children's products, and proposes a new method for the determination of the migration of wood preservatives , can simultaneously measure the content and migration of 10 polychlorinated phenols and pyrethroid preservatives in the sample. In addition, (1) wood samples adopt a specific sampling method to make the design of migration experiments more theoretically based, and at the same time more conducive to the production of positive standard samples. Through the design reverse deduction experiment, under the condition that the wood preservative migrates from the wood surface to the interior with the simulated saliva for a long time, the content of the wood preservative in the 3mm of the wood surface is much greater than that in the interior, so it is deduced that when the migration behavior actually occurs, it is mainly the wood surface The wood preservative within 3mm migrates out, so the surface layer 3mm can be taken when sampling. (2) The setting of the pH value of the derivatization reaction of the migration solution. Since the properties of polychlorinated phenols and pyrethroids are quite different, the determination of polychlorinated phenols by gas chromatography needs to be carried out in potassium carbonate solution medium first. derivatization with acetic anhydride. After the migration test is completed, the derivatization medium is simulated saliva, simulated sweat or water. This research method is carefully optimized and the recovery rate is used to determine the best derivatization pH value for the 10 wood preservatives. The value was found in the study changes have a significant impact on the results of the entire study.

According to the use characteristics of wooden children's products, by setting different experimental simulation conditions, based on the determination of the total content and migration amount of each preservative in the sample, the results obtained are summarized and analyzed, and the wooden children's products are obtained. The maximum mobility and migration rules of wood preservatives in China.

For 10 kinds of wood preservatives, prepare positive standard samples with different contents, migrate in the migration solution for 1-10 hours respectively, set the temperature of the water bath at 37°C, take samples and measure the migration amount of each substance under the simulated experimental conditions, and draw the results together , can intuitively analyze the migration behavior, and discuss the factors that affect the migration law. By measuring the actual total content of the 10 substances in all the above-mentioned positive samples, and comparing all the migration values with the corresponding total values, the mobility of each substance within 10 hours is obtained. Among them, the maximum value of the mobility of each substance within 10 hours is the maximum mobility. By comparing the maximum mobility of each substance in different migration solutions in positive samples with different contents, and confirming with the previous results, 10 kinds of Migration rules of wood preservatives.

The method for researching the migration law of wood preservatives in wooden children's products of the present invention has good selectivity and sensitivity for the determination of the total amount and migration amount of target substances in wood samples with complex substrates, and is easy to operate and has obvious effects. The experimental design of the migration law of 10 wood preservatives has a more theoretical basis, which is more conducive to the production of positive standard samples, and at the same time ensures that the research results of the migration law are more accurate and reliable.

Below in conjunction with accompanying drawing, the research method of wood preservative migration rule in wooden children's products of the present invention will be further described.

Description of drawings

Fig. 1 is the MRM chromatogram of 10 kinds of wood preservative standard solutions in the research method of wood preservative migration rule in wooden children's products of the present invention; The preservative kind that numbering represents is identical with table 1;

Fig. 2 is the schematic diagram of the experimental results of 10 kinds of wood preservatives migrating from simulated saliva to the interior of wood in the research method of the migration law of wood preservatives in wooden children's products of the present invention; wherein, A: 0 ~ 3mm; B: 3 ~ 6mm; C: remaining wood sample;

Fig. 3 is the schematic diagram of the relative recoveries of 10 kinds of substances in simulated saliva under different pH values in the research method of wood preservative migration law in wooden children's products of the present invention;

Fig. 4 is the schematic diagram of the relative recoveries of 10 kinds of substances in simulated sweat under different pH values in the research method of wood preservative migration law in wooden children's products of the present invention;

Fig. 5 is a schematic diagram of the migration results of 10 wood preservatives at 37°C in the method for researching the migration rules of wood preservatives in wooden children's products according to the present invention.

detailed description

Example 1

A method for researching the migration law of wood preservatives in wooden children's products, characterized in that it comprises the following steps:

1. Preparatory work

1. Instruments and reagents

7890A gas chromatograph (Agilent, USA); Quattro Micro triple quadrupole mass spectrometer (Waters, USA); solid phase extraction device (Supelco, USA); NVC-2000 rotary evaporator (Eyela, Japan); SM2000 cutting and grinding Instrument (Retsch, Germany); TechCut4 low-speed cutting machine with micro-tooth saw blade (Allied, USA); NTS-4000 constant temperature water bath oscillator (Eyela, Japan); Oasis HLB solid-phase extraction column (6mL, 200mg, Waters, USA) ).

Standard: 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4-trichlorophenol, 2,3,4,6-tetrachlorophenol, lindane, cypermethrin, cyfluthrin , deltamethrin were purchased from Accustomard Company, purity ≥ 98%; pentachlorophenol and 2,4 dichlorophenol were purchased from Dr.Ehrenstorfer Company, purity ≥ 99%; permethrin was purchased from Fluka Company, purity ≥ 98% ; Wherein, permethrin, cypermethrin, and cyfluthrin are mixtures of isomers. The experimental water is deionized water prepared by the Milli-Q system; helium and argon (>99.999%); the ethanol, acetic acid, and acetic anhydride used in the experiment are analytically pure, and other reagents are chromatographically pure.

2. Solution preparation

Substances to be tested: Weigh 100mg of each of the 10 preservative standard products into a 100mL brown volumetric flask, dilute to volume with 9:1 (v/v) ethanol/glacial acetic acid solution, and prepare a single-label stock solution with a concentration of 1000mg/L , use the single standard stock solution to prepare a fully mixed stock solution with a concentration of 100mg/L. According to the needs in the experiment, a series of working solutions can be diluted to the required concentration with 9:1 (v/v) ethanol/glacial acetic acid.

Internal standard substance: Weigh 50mg of 2,3,4-trichlorophenol into a 100mL brown volumetric flask, dilute to volume with 9:1 (v/v) ethanol/glacial acetic acid solution, and prepare a 500mg/L internal standard stock solution. It was then diluted to a concentration of 5 mg/L internal standard working solution.

Simulated saliva: sodium chloride 4.5g, potassium chloride 0.3g, sodium sulfate 0.3g, ammonium chloride 0.4g, 90% lactic acid 3.0g, urea 0.2g, deionized water to 1000mL, pH ≈ 3. Simulated sweat: sodium bicarbonate 4.2g, sodium chloride 0.5g, potassium carbonate 0.2g, deionized water to 1000mL, pH ≈ 8.8.

3. Preparation of positive samples

Crush the blank wood sample into wood chips less than 2mm with a grinder, weigh an appropriate amount of wood chips into a round-bottomed flask with a stopper, add an appropriate amount of fully mixed standard solution to an Erlenmeyer flask, and add an appropriate amount of methanol to dilute to ensure that the diluted solution Pour into a round bottom flask to submerge all sawdust. Place the round-bottomed flask on a shaker for 2 hours and let it stand overnight to ensure that the preservative fully penetrates into the wood. Then rotary evaporate at 35°C and 170hPa (gradually transition from 300hPa to 170hPa to avoid solution bumping), and slowly evaporate the solvent to nearly dryness. Spread the nearly dry wood chip sample on a large surface dish until the solvent is completely evaporated, that is, a positive sample is obtained.

2. Determination method

(1) Determination of the total amount of each preservative in the sample:

Crush the sample to less than 2mm sawdust, accurately weigh 2g, and ultrasonically extract 2 times with methanol, 20mL each time, for 15min. Filter and combine the filtrate into a centrifuge tube, add 1mL internal standard working solution, centrifuge at 4°C and 13000r/min for 5min, filter through a 0.45μm PTFE filter membrane, transfer to a chicken heart bottle, and concentrate by rotary evaporation at 35°C and 170hpa to 2 mL. Add 40mL of 0.1mol/L potassium carbonate solution to the concentrated solution, shake well, add 1mL of acetic anhydride for derivatization, deflate while shaking, operate for about 1min, then place on a shaking table and shake for 10min. Pass the derivatized solution through an Oasis HLB solid-phase extraction column activated by 5 mL of methanol and equilibrated with 5 mL of deionized water in advance, rinse with 5 mL of deionized water, use a vacuum pump to dry the water, and finally elute with 10 mL of ethyl acetate. The eluate was collected and dried by adding an appropriate amount of anhydrous sodium sulfate, vortexed for 30s, and tested on the machine.

(2) Determination of the migration amount of each preservative in the sample:

Use a low-speed cutting machine to cut the surface layer of the wood sample with a thickness of 3mm, crush it into wood chips less than 2mm by a grinder, accurately weigh 2g of the sample into a 50mL stoppered test tube, add 40mL of migration solvent, and shake in a water bath at 37°C and 100r/min (1～ After 10h), pass through a 200μm stainless steel filter to obtain a migration solution. Add 1 mL of internal standard working solution to the migration solution, adjust the pH value to 6, add 1 mL of acetic anhydride for derivatization, operate for about 1 min, and place on a shaker for 10 min. Pass the derivatized solution through an Oasis HLB solid-phase extraction column activated by 5 mL of methanol and equilibrated with 5 mL of deionized water in advance, rinse with 5 mL of deionized water, use a vacuum pump to dry the water, and finally elute with 10 mL of ethyl acetate. The eluate was collected and dried by adding an appropriate amount of anhydrous sodium sulfate, vortexed for 30s, and tested on the machine.

Among them, the chromatography-mass spectrometry conditions are specifically:

Agilent HP-5MS chromatographic column (30m×0.25mm i.d., 0.25μm); inlet temperature 280°C; carrier gas flow rate 1.0mL/min; splitless injection, injection volume 2μL; temperature program: initial temperature 60°C , rise to 200°C at 20°C/min, then rise to 280°C at 10°C/min (hold 8min); solvent delay 5min; transfer line temperature 250°C; ion source temperature 180°C; EI ionization mode, ionization energy 70eV, MRM Pattern determination.

(3) According to the characteristics of the use of wooden children's products, by setting different experimental simulation conditions, based on the determination of the total content and migration amount of each preservative in the sample, the results obtained are summarized and analyzed, and the wooden The maximum migration rate and migration law of wood preservatives in children's products.

3. Results and Analysis

1. Detection method of the total amount of wood preservatives

Based on the SPE-GC-MS/MS technology, the present invention establishes a method for simultaneous determination of the 10 wood preservatives in wooden children's products. The results show that the method has good selectivity and sensitivity for the detection of targets in wood samples with complex matrices. Under the chromatographic mass spectrometry conditions described in the present invention, the typical chromatographic separation diagrams of 10 substances are shown in Fig. 1 .

The blank sample in the present invention is a kind of beech wood with a clean matrix and no substance to be tested. Using the blank sample as the matrix, the detection limit, quantification limit and linear range of each substance were obtained through the standard addition experiment. The chromatographic and mass spectrometric parameters of each substance are listed in Table 1.

Table 1 CAS, chromatographic retention time, linear range, and mass spectrometry parameters of the substances to be tested

*Precursor ion>quantitative ion (collision energy, eV).

2. Determination of the sampling method of wood samples

Select 3 cube-shaped beech blank samples with a side length of 3cm, place them in a 500mL beaker, add 50mL of 100mg/L fully mixed standard solution, add an appropriate amount of simulated saliva and mix well, and immerse the wood samples completely (you can use a suitable small weight object or support), sealed. The 3 samples were soaked for 1h, 5h and 24h respectively, then taken out, and left to dry overnight in the fume hood. For the sample soaked for 1h, use a low-speed cutting saw to cut the 6 surfaces of the sample sequentially from the outside to the inside to obtain 3 groups of wood chips, of which the 0-3mm layer is the A sample; the 3-6mm layer is the B sample; and the remaining wood inside is the C sample. The same is true for samples soaked for 5h and 24h; according to the established total amount determination method, the content of 10 wood preservatives were measured for the obtained 9 samples to be tested, and the results are shown in Figure 2.

It can be seen from Figure 2 that with the increase of soaking time, the content of wood preservatives in the samples showed an overall increasing trend. Wood preservatives migrated from the wood surface to the interior with saliva, and the content in sample A was much higher than that of samples B and C. Even under the condition of soaking for 24 hours, the substances did not completely penetrate evenly inside the wood. The content of pyrethroids in sample A is more than 5 times that of B+C, while that of polychlorinated phenols is more than 32 times. In the actual migration experiment, the research is that the wood preservative migrates from the inside of the wood to the outside with the migration solution. It can be judged by the reverse deduction method that the actually migrated substances are mainly in the 3mm surface layer, and 3mm to the inner center of the wood. It is difficult for the agent substance to migrate out with the migration solution. Therefore, the sampling method of this migration experiment is determined to take the 3mm layer on the surface of the sample; in order to facilitate the production of positive standard samples with known content and to explore the migration law, the wood sample is taken from the surface 3mm layer and crushed by a grinder.

The wood sample mentioned in step (2) adopts a specific sampling method, so that the design of the migration experiment has a more theoretical basis, and it is more conducive to the production of positive standard samples. Through the design reverse deduction experiment, under the condition that the wood preservative migrates from the surface of the wood to the interior with the migration solvent for a long time, the content of the wood preservative in the 3mm of the surface layer of the wood is much greater than that in the interior. The wood preservative in the surface 3mm migrates out, so the surface 3mm can be taken when sampling.

3. The influence of the pH value of the migration solution

In the total test of wood preservatives, polychlorinated phenols need to be derivatized by acetic anhydride reagent in 0.1mol/L potassium carbonate solution, and the medium of the migration test is a migration solvent such as simulated saliva, simulated sweat or water. It is more convenient to be able to carry out derivatization directly in the migration solution after the experiment. Add standard to 40mL simulated saliva, simulated sweat, and potassium carbonate solution respectively, adjust the pH value of simulated saliva and sweat to 2-9, and then add acetic anhydride for derivatization. Based on the recovery rate of potassium carbonate solution as 100%, the relative recoveries of 10 substances in the migration solution at different pH were obtained. It can be seen from Figure 3 and Figure 4 that the recovery rates of the ten substances are significantly affected by the pH value of the migration solution, and the recovery rates of polychlorinated phenols are very low under acidic conditions. High recovery rate; pyrethroids are relatively stable under acidic and neutral conditions, and the recovery rate begins to deteriorate at higher pH values. Comprehensive consideration, choosing to adjust the pH value of the migration solution to 6 after the migration experiment is over, can guarantee a satisfactory recovery rate for all substances.

After adding 1mL of the internal standard working solution to the migration solution described in step (2), setting the pH value to 6 has a decisive effect on the results of the entire experiment. Since the properties of polychlorinated phenols and pyrethroid wood preservatives are quite different, the determination of polychlorinated phenols by gas chromatography needs to be derivatized with acetic anhydride in potassium carbonate solution medium first. After the migration test is completed, the derivatization medium is simulated saliva, simulated sweat or water. This research method is carefully optimized and the recovery rate is used to determine the best derivatization pH value for the 10 wood preservatives. The value was found in the study The change of has a significant impact on the research results of the entire migration law.

4. Obtain the migration law and maximum mobility through experimental simulation

For polychlorinated phenols, prepare positive samples of 5 mg/kg and 10 mg/kg, for pyrethroids, prepare positive samples of 50 mg/kg and 100 mg/kg, respectively migrate in simulated saliva and sweat for 1 to 10 hours, and set the temperature of the water bath at 37°C (human body temperature under normal use conditions), samples were taken to measure the migration of each substance under simulated experimental conditions, and the results are summarized in Figure 5. It should be noted that the detection amount of deltamethrin has been lower than its limit of quantification, but the migration amount is still converted from the linear equation, which is for reference only.

Analyzing the data in Figure 5, it is concluded that the 10 substances mainly have the following migration rules:

(1) Within 10 hours of migration, the laws reflected by each substance are not the same. With the increase of migration time, the migration amount of polychlorinated phenols in the sample showed an overall increasing trend. For example, the migration amount of 2,4-dichlorophenol, 5mg/kg and 10mg/kg positive samples in saliva and sweat all increased with increase with time. However, the migration amount of pyrethroids in the sample is basically stable with time, such as cyfluthrin. This may be due to the fact that pyrethroids reached equilibrium in the wood body and the migration medium in a relatively short period of time.

(2) The migration amount of wood preservatives with the same content in sweat is obviously higher than that in saliva. Such as 2,3,4,6-tetrachlorophenol, the average migration amount of 5mg/kg positive sample in sweat is 9.1 times higher than that in saliva, and 10mg/kg positive sample is 8.6 times higher. However, for different substances, this difference is not completely consistent. For example, the migration amount of 5mg/kg positive sample of Lindane in sweat is almost equal to that in saliva, and the migration amount of 10mg/kg positive sample in sweat is slightly higher than that in saliva.

(3) For polychlorinated phenols, in the same migration medium, the migration amount of samples with high content of wood preservatives was significantly higher than that of samples with low content. Such as pentachlorophenol, the average migration amount of 10mg/kg positive samples in sweat is 2.9 times higher than that of 5mg/kg positive samples, and the difference in saliva is 2.5 times. The law of pyrethroids in sweat is the same as that of polychlorinated phenols, but in saliva, the migration amount is not very obviously affected by the content of substances in the sample.

By measuring the actual total content of the 10 substances in all the above-mentioned positive standard samples, and comparing all the migration values with the corresponding total values, the mobility of each substance within 10h is obtained. The maximum values of the mobility of each substance within 10 h are listed in Table 2 and Table 3.

It can be seen from the data in the table that the maximum mobility of pyrethrins within 10 hours is almost all less than 1%, and deltamethrin in 100mg/kg positive samples has the lowest mobility in saliva, only 0.1%. However, the mobility of polychlorinated phenols is significantly higher, all above 3%. For example, the maximum mobility of 2,4,6-trichlorophenol in sweat in 10mg/kg samples can even reach 69%. Such a significant difference may be related to the solubility of the two types of substances in aqueous solution. Polychlorinated phenols are generally slightly soluble in water. For example, the solubility of pentachlorophenol in water is 14mg/L, and the solubility of 2,4,6-trichlorophenol Solubility in water is 0.8g/L, and pyrethroids are hardly soluble in water, such as permethrin has a solubility of less than 0.03mg/L in water, and deltamethrin is almost insoluble in water at room temperature.

This can also be verified with other experimental results obtained in this paper. In Figure 2, the wood preservative penetrates into the wood sample through saliva, and the content of pyrethroids in samples B and C obtained is significantly higher than that of polychlorinated phenols. Pyrethrin substances are easy to penetrate into the wood through saliva, and correspondingly, it is not easy to migrate into the human body through saliva during actual use, while polychlorinated phenols are easier to migrate into the human body through saliva. In Figure 5, due to the good solubility in water, polychlorinated phenols gradually migrate from the interior of the wood to the solution with the increase of migration time, so there is an increasing trend. However, pyrethroids are insoluble in water, and the amount of migration did not increase significantly with time, which may be due to the equilibrium between the wood body and the migration medium in a relatively short period of time.

Table 2 The initial content of polychlorinated phenols in the positive sample and the maximum mobility in the migration medium

Table 3 The initial content of pyrethroids in the positive sample and the maximum mobility in the migration medium

The above-mentioned embodiments are only descriptions of preferred implementations of the present invention, and are not intended to limit the scope of the present invention. Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

Claims (7)

1. a research method on the migration law of wood preservatives in wooden children's articles, is characterized in that: comprise the steps: (1) by self-made positive standard samples containing 10 wood preservatives, use gas chromatography-tandem mass spectrometry to determine the actual total content of each preservative in the sample; (2) Determination of the migration amount of each preservative in the positive sample: use a low-speed cutting machine to cut the surface layer of the wood sample with a thickness of 3mm, grind it into wood chips less than 2mm by a grinder, accurately weigh 2g of the sample into a 50mL stoppered test tube, and add the migration solvent 40mL, the migration solvent is simulated saliva, simulated sweat or water, oscillated in a water bath at 37°C and 100r/min for 1-10h, and passed through a 200μm stainless steel filter to obtain a migration solution; add 1mL internal standard to the migration solution For the working solution, adjust the pH value to 6, add 1mL acetic anhydride for derivatization, operate for about 1min, place on a shaker and shake for 10min; pass the derivatized solution through Oasis HLB activated in advance with 5mL methanol and equilibrated with 5mL deionized water The solid-phase extraction column was rinsed with 5mL deionized water, drained with a vacuum pump, and finally eluted with 10mL ethyl acetate. The eluate was collected and dried by adding an appropriate amount of anhydrous sodium sulfate. After vortexing for 30s, the gas chromatography-tandem Determination by mass spectrometry detection method; (3) According to the use characteristics of wooden children's products, by setting different experimental simulation conditions, based on the determination of the total content and migration of each preservative in the sample, the results obtained are summarized and analyzed, and the wooden The maximum migration rate and migration law of each wood preservative in children's products; The method simultaneously measures the total content and migration amount of 10 preservative substances in the sample, and conducts research on the migration law through experimental simulation conditions. The preservatives are 2,4-dichlorophenol, 2,4,5-trichlorophenol Phenol, 2,4,6-Trichlorophenol, 2,3,4,6-Tetrachlorophenol, Lindane, Pentachlorophenol, Cypermethrin, Cyfluthrin, Permethrin, and Deltamethrin. 2. The research method of wood preservative migration law in wooden children's products according to claim 1, is characterized in that: step (3) specifically comprises the following steps: for polychlorinated phenols, prepare 5mg/kg and 10mg/kg kg positive standard sample, prepare 50mg/kg and 100mg/kg positive samples for pyrethroid substances, respectively migrate in different migration solvents for 1-10h, set the temperature of the water bath at 37°C, take samples and determine each substance under simulated experimental conditions The migration amount, the results are summarized and plotted, and the migration behavior is analyzed intuitively; by measuring the actual total content of the 10 substances in all positive samples, the ratio of the migration amount to the corresponding total value is calculated, that is, the ratio of each substance in 10h The maximum mobility of each substance within 10h is the maximum mobility. By comparing the maximum mobility of each substance in different migration solvents in positive samples with different contents, and comparing with the previous results, Finally, the migration laws of 10 kinds of wood preservatives were obtained. 3. the research method of wood preservative migration rule in wooden children's products according to claim 2, is characterized in that: also comprise the preparation of positive sample, comprise the steps: blank wood sample is pulverized into less than 2mm with grinder Sawdust, weigh an appropriate amount of sawdust in a round-bottomed flask with a stopper, add a fully mixed standard solution into an Erlenmeyer flask, and add methanol to dilute to ensure that the diluted solution can be poured into the round-bottomed flask to immerse all the sawdust; Place the bottom flask on a shaker for 2 hours and then let it stand overnight to ensure that the preservative fully penetrates into the wood, and then rotate it at 35°C and 170hPa. During the rotary evaporation process, the pressure gradually transitions from 300hPa to 170hPa, and the solvent is slowly evaporated to near dryness. , spread the nearly dry wood chip sample on a large surface dish until the solvent is completely evaporated, that is, a positive sample is obtained. 4. The method for researching the migration law of wood preservatives in wooden children's products according to claim 3, characterized in that: the internal standard working solution is prepared by the following method: weighing 50mg 2,3,4-tri Chlorophenol in a 100mL brown volumetric flask, dilute to volume with ethanol/glacial acetic acid solution with a volume ratio of 9:1, prepare a 500mg/L internal standard stock solution, and then dilute it to a concentration of 5mg/L for internal standard work solution. 5. the research method of wood preservative migration rule in the wooden children's article according to claim 4, is characterized in that: The preparation method of the simulated saliva is prepared by the following method: respectively weigh 4.5g of sodium chloride, 0.3g of potassium chloride, 0.3g of sodium sulfate, 0.4g of ammonium chloride, 3.0g of 90% lactic acid, 0.2g of urea, After mixing, dilute to 1000mL with deionized water, pH≈3; The simulated sweat is prepared by the following method: Weigh 4.2g of sodium bicarbonate, 0.5g of sodium chloride, and 0.2g of potassium carbonate, mix them and dilute to 1000mL with deionized water, pH≈8.8. 6. The research method of the migration law of wood preservatives in wooden children's products according to claim 1, characterized in that: step (1) specifically comprises the following steps: crush the sample to less than 2mm sawdust, accurately weigh 2g, and use Ultrasonic extraction of methanol twice, each time 20mL, extract 15min, filter and combine the filtrate into a centrifuge tube, add 1mL internal standard working solution, centrifuge at 4°C, 13000r/min for 5min, filter through a 0.45μm PTFE membrane and transfer Put it into a chicken heart bottle, concentrate it to 2mL by rotary steaming at 35°C and 170hpa, add 40mL 0.1mol/L potassium carbonate solution to the concentrated solution, shake well, add 1mL acetic anhydride for derivatization, deflate while shaking, and operate for about 1min After that, it was shaken on a shaker for 10 minutes, and the derivatized solution was passed through an Oasis HLB solid-phase extraction column activated by 5 mL of methanol and balanced by 5 mL of deionized water in advance, rinsed with 5 mL of deionized water, and dried by a vacuum pump. Elute with 10 mL of ethyl acetate, collect the eluate and add an appropriate amount of anhydrous sodium sulfate to dry, vortex for 30 s, and then use gas chromatography-tandem mass spectrometry for detection. 7. The research method of the migration law of wood preservatives in wooden children's products according to claim 1, characterized in that: the chromatography-mass spectrometry condition of the gas chromatography-tandem mass spectrometry detection method is: Agilent HP-5MS chromatographic column, The specification is 30m×0.25mm i.d., 0.25μm; the temperature of the injection port is 280°C; the flow rate of the carrier gas is 1.0mL/min; splitless injection, the injection volume is 2μL; Raise to 200°C, then rise to 280°C at 10°C/min and hold for 8min; solvent delay 5min; transfer line temperature 250°C; ion source temperature 180°C; EI ionization mode, ionization energy 70eV, MRM mode measurement.