CN112114064A - A kind of detection method of volatile organic compounds in furniture - Google Patents

Abstract

The invention discloses a method for detecting volatile organic compounds in furniture. Specifically, the furniture to be detected is placed in a climate chamber, sampling is carried out after 20±0.5h, and the sampling time is 1±0.5h, and then the cleaned and pumped The vacuumed Summa tank is connected to the climate chamber, and the volatile organic gases are sampled at a constant flow. After sampling, the pressure in the Summa tank is diluted with high-purity nitrogen to make the pressure in the Summa tank reach 101kPa, and then the volatile organic gas in the Summa tank is The gas was transferred to the cold trap concentrator for concentration, and the internal standard standard gas was added at the same time. After the gas was concentrated, it was detected by GC-MS. The invention adopts the climate chamber to simulate the daily environment, and collects the released volatile organic compounds into the vacuum suma tank, which greatly reduces the loss of volatile organic compounds in the furniture during the sampling process, and maintains the integrity of the furniture to the greatest extent possible. Simultaneously screen and detect a variety of volatile organic compounds, with low detection limit, high accuracy, strong operability and fast speed.

Description

A kind of detection method of volatile organic compounds in furniture

technical field

The invention belongs to the technical field of indoor environment inspection, in particular to a method for detecting volatile organic compounds in furniture.

Background technique

With the continuous development of the home improvement market, various problems in home improvement also follow. Especially indoor environmental pollution, because of its harmfulness to human body, has attracted more and more people's attention. The source of indoor environmental pollution, VOC, has gradually surfaced. VOCs are organic (carbon-based) gases, also known as hydrocarbons, emitted by many different products. Evaporation of VOCs is caused by sufficient pressure. Common sources of indoor VOCs are building materials, carpets, printers, furniture, paint thinners, glues, cosmetics and certain sprays, and plastics. According to the Environmental Protection Agency, if there is not enough ventilation to circulate the air and VOCs are present indoors, indoor air pollution can be as much as 10 times worse than outdoor air.

The main components of VOC are: hydrocarbons, halogenated hydrocarbons, oxygen hydrocarbons and nitrogen hydrocarbons, which include: benzene series, organic chlorides, Freon series, organic ketones, amines, alcohols, ethers, esters, acids and petroleum hydrocarbon compounds Wait. VOC is the English abbreviation of Volatile Organic Compounds. Generally speaking, the chemical substances (except heavy metals) that are harmful to human body in wall paint refer to VOC. These volatile organic compounds include formaldehyde, ammonia, ethylene glycol, esters and other substances. When the VOC in the room reaches a certain concentration, it will cause symptoms such as headache, nausea, vomiting, fatigue, and even convulsions, coma, damage to the liver, kidneys, brain and nervous system, resulting in serious consequences such as memory loss.

With the rapid economic development, my country's furniture industry has developed rapidly, accelerating the innovation of furniture product processing technology and the application of new materials. However, at the same time, some raw and auxiliary materials and production and processing techniques in furniture products may bring certain harmful substances to furniture products during the production process, including volatile organic compounds that consumers are increasingly concerned about. At present, there is no special testing equipment for such harmful substances in furniture products on the market, so it is very important to develop a detection method for volatile organic compounds in furniture.

On the other hand, furniture products are bulk durable consumer goods. If traditional testing methods are used for destructive testing of furniture products, it will inevitably cause unnecessary waste, increase the burden on enterprises and increase operating costs. At the same time, the results cannot truly reflect the release of furniture under daily use conditions. Type and content of volatile organic compounds. Thermal desorption-GC/MS method can only collect a small part of volatile organic compounds, the information obtained is limited, and the procurement cost of the sampling tube is high, the service life is short, and it is easily affected by temperature and humidity. The post-retention time is short, easy to lose, and has great limitations. Aldehyde and ketone sampling tube with liquid chromatography can only collect aldehyde and ketone compounds, and the scope of application is quite limited.

SUMMARY OF THE INVENTION

Aiming at the problems in the prior art that the existing detection methods have limited information acquisition, high cost and easy damage to furniture, the invention discloses a detection method for volatile organic compounds in furniture, which greatly reduces the sampling process. It can reduce the loss of volatile organic compounds in furniture, and maintain the integrity of the furniture to the greatest extent possible, and can detect a variety of volatile gases at the same time with high accuracy.

The present invention is achieved through the following technical solutions:

A method for detecting volatile organic compounds in furniture. The furniture to be tested is placed in a climate chamber, the volatile organic compounds released are collected in a vacuum suma tank, and the volatile organic compounds in the suma tank are concentrated and then transferred to GC-MS instrument to detect.

Further, described detection method comprises the following steps:

(1) Put the furniture to be tested in the climate chamber, sample after 20±0.5h, and the sampling time is 1±0.5h;

(2) Connect the cleaned and evacuated Summa tank to the climate chamber, and conduct constant-current sampling for volatile organic gases. After sampling, pressurize and dilute with high-purity nitrogen to make the pressure in the Summa tank reach 101kPa;

(3) Transfer the volatile gas in the Summa tank to the cold trap concentrator for concentration, and add the standard gas used for the internal standard at the same time. After the gas is concentrated, it is detected by GC-MS.

Further, the furniture is pretreated before being put into the climate chamber. The pretreatment method is to assemble the furniture according to the style most conducive to the release of harmful substances. The pretreatment time is 120±2h, and the temperature is 23±2℃. The relative humidity is 45±10%, the distance between samples is less than 300mm, the formaldehyde concentration between samples is less than or equal to 0.10 mg/m ³ , and the TVOC concentration is less than or equal to 0.60 mg/m ³ .

Further, the load-bearing rate of the climate chamber described in step (1) is 0.075~0.3, the temperature is 23±2°C, the relative humidity is 45±10%, the aldehyde concentration in the feed air is ≤0.10mg/m ³ , TVOC Concentration ≤ 0.60 mg/m ³ ; the suma tank described in step (2) should be humidified and cleaned before use, and the cleaning temperature is 80° C. After cleaning, it is evacuated to a vacuum.

Further, the internal standard standard gas is more than one of bromo-chloromethane, 1,2-difluorobenzene and chlorobenzene-d5.

Further, in step (3), the amount of volatile gas in the Summa tank transferred to the cold trap concentrator is 50-1000 mL, preferably 400 mL; the concentration of the gas used for the internal standard standard is 100 nmol/mol.

The detection method according to claim 2, wherein the size of the suma tank is 6L, the sampling flow rate is 90mL/min, and the sampling time is 1 hour.

Further, the collection conditions of the cold trap concentrator are: the first-stage cold trap trapping temperature is -150°C, the trapping flow rate is 100mL/min, the desorption temperature is 10°C, the valve temperature is 100°C, and the baking temperature is 150°C. , the baking time is 15min; the trapping temperature of the secondary cold trap is -15°C, the trapping flow rate is 10mL/min, the capture time is 5min, the desorption temperature is 180°C, the desorption time is 3.5min, the baking temperature is 190°C, and the baking time is 190°C. The time is 15min; the focusing temperature of the third-level focusing is -160℃, the analysis time is 2.5min, the baking temperature is 200℃, and the baking time is 5min;

The gas chromatography-mass spectrometry conditions are as follows: a quartz capillary column with a polarity index of less than 10, the temperature is programmed to increase at 40°C for 1 min, the temperature is increased to 100°C at 3°C/min, and then the temperature is increased to 250°C at 10°C/min, and the temperature is maintained at 10°C/min. 10min, carrier gas is helium, flow rate is 1.2mL/min; chromatography-mass spectrometry interface temperature is 260℃; ion source is electron ionization source, temperature is 260℃; ionization energy is 70eV; mass analyzer is quadrupole mass analyzer ; The quality scanning range is 25~450amu; the scanning mode is full scanning mode.

Further, the detection method is used for qualitative and quantitative analysis of volatile organic compounds in furniture.

Before the volatile organic gas in the furniture is tested for concentration, the pressure in the Summa tank is measured with a vacuum pressure gauge. If the pressure in the tank is less than 83kPa, pressurize it to 101kPa with high-purity nitrogen, and calculate the dilution ratio according to formula (1):

In the formula: f——dilution factor, dimensionless;

X _a — tank pressure before dilution, kPa;

Y _a ——Diluted tank pressure, kPa.

Calculation of the relative impact factor (RRF) of the target substance in the furniture: use the atmospheric pre-concentrator to extract 50mL, 100mL, 200mL, 400mL, 600mL, 800mL of standard gas, and add 50mL of internal standard gas to prepare the target. The concentration of 1.25nmol/mol, 2.5nmol/mol, 5.0nmol/mol, 10.0nmol/mol, 15.0nmol/mol, 20.0nmol/mol standard series, the internal standard concentration is 12.5nmol/mol, atmospheric concentrator The sampling volume is 400mL. According to the instrument reference conditions in step 5, measure from low concentration to high concentration in turn. Calculate the relative impact factor of the target according to formula (2), and calculate the total standard concentration point of the target according to formula (3). Average relative impact factor (RRF);

In the formula: RRF——the relative response factor of the target, dimensionless;

A _x ——the quantitative ion peak area of the target compound;

A _{is ——the} quantitative ion peak area of the internal standard compound;

ψ _is ——the mole fraction of the internal standard compound, nmol/mol;

ψ _x ——The mole fraction of the target compound, nmol/mol.

In the formula: RRF——the average relative response factor of the target, dimensionless;

RRF _i - the relative response factor of the i-th target in the standard series, dimensionless;

n——Standard series points.

The qualitative analysis of volatile organic compounds in furniture is carried out in a full-scan manner. The relative retention time of the target substances in the sample, the abundance ratio between the auxiliary qualifier ions and the quantitative ions, and the comparison of the target substances in the standard are used to determine the quality. The relative retention time of the target compound in the sample should be within ±3.0% of the relative retention time of the compound in the calibration series. The relative deviation between the peak area ratios of auxiliary qualifier ions and quantification ions of the target compounds in the sample (Q sample) and that of the standard series of target compounds was controlled within ±30%.

Calculate the relative retention time of the target according to formula (4):

In the formula: RRT——relative retention time of target compound, dimensionless;

RT _c — retention time of target compound, min;

RT _{is ——retention} time of internal standard, min.

Calculate the mean relative retention time (RRT) according to formula (5): The average relative retention time of the same target compound in the standard series.

In the formula: RRT——the average relative retention time of the target, dimensionless;

RRT _i - the relative retention time of the i-th target in the standard series, dimensionless;

n——Standard series points.

Calculate the peak area ratio of auxiliary qualifier ion and quantitative ion according to formula (6)

In the formula: Q——the peak area ratio of auxiliary qualifier ion and quantitative ion;

_{At ——quantitative} ion peak area;

A _q ——Auxiliary qualifier ion peak area.

The quantitative analysis of volatile organic compounds in furniture uses the average relative response factor for quantitative calculation, and the quantitative ions of the target substances and the corresponding relationship between each target substance and the internal standard substance refer to Appendix C. The content of the target substance (μg/m3) in the sample was calculated according to formula (7).

In the formula: ρ——the concentration of the target substance in the sample, μg/m ³ ;

A _x - the quantitative ion peak area of the target in the sample;

A _is - the quantitative ion peak area of the internal standard in the sample;

ψ _is ——the mole fraction of the internal standard in the sample, nmol/mol;

RRF - the average relative response factor of the target, dimensionless;

f ——dilution factor, dimensionless;

M——the molar mass of the target substance, g/mol;

22.4 — Molar volume of gas in standard state (273.15 K, 101.325 kPa), L/mol.

beneficial effect

(1) The present invention uses a climate chamber to simulate the daily environment, and collects the released volatile organic compounds into the vacuum suma tank, which greatly reduces the loss of volatile organic compounds in the furniture during the sampling process, and maximizes the preservation of the furniture. completeness;

(2) The present invention can simultaneously screen and detect various volatile organic compounds, with low detection limit, high accuracy, strong operability and fast speed, and can realize qualitative and quantitative detection of various volatile organic compounds in furniture.

Description of drawings

Figure 1 is the gas chromatography-mass spectrometry selected ion chromatogram of volatile benzene series in furniture (wherein, 1. RT 6.88, benzene; 2. RT 9.83, toluene; 3. RT 12.70, vinylcyclohexene; 4. RT 13.66, ethylbenzene; 5. RT 13.97, p-xylene; 6. RT 13.97, m-xylene; 7. RT 14.10, phenylacetylene; 8. RT 14.87, styrene; 9. RT 15.11, ortho Xylene; 10. RT 16.69, cumene; 11. RT 18.15, n-propylbenzene; 12. RT 18.54, 3-ethyltoluene; 13. RT 18.93, 1,3,5-trimethylbenzene; 14 . RT 19.41, α-phenylpropene; 15. RT 19.43, 2-ethyltoluene; 16. RT 20.03, vinyltoluene; 17. RT 21.21, 1,2,4-trimethylbenzene; 18. RT 21.51, 1,2,3-trimethylbenzene; 19. RT 21.74, 1-isopropyl-4-methylbenzene; 20. RT 22.28, indene; 21. RT 22.31, 1-isopropyl-2-methyl Benzene; 22. RT 23.01, n-butylbenzene; 23. RT 25.05, 1,2,4,5-tetratoluene; 24. RT 26.11, 1,3-diisopropylbenzene; 25. RT 26.61, 1 ,4-diisopropylbenzene; 26. RT 26.67, naphthalene; 27. RT 29.85, 4-phenylcyclohexene; 28. RT 31.97, octylbenzene, RT is retention time);

Fig. 2 is the gas chromatography-mass spectrometry selected ion chromatogram of volatile alcohols in furniture (1. RT 4.85, 2-propanol; 2. RT 5.05, tert-butyl alcohol (2-methyl-2-propanol); 3. RT 5.32, 1-propanol; 4. RT 6.26. 2-methyl-1-propanol; 5. RT 6.92, 1-butanol; 6. RT 14.05, 1-hexanol; 7. RT 14.57, Cyclohexanol; 8. RT 19.19, phenol; 9. RT 21.45, benzyl alcohol; 10. RT 21.96, 2-ethyl-1-hexanol; 11. RT 23.6, 1-octanol; 12. RT 32.55, butyl alcohol hydroxytoluene, RT is retention time);

Figure 3 is a gas chromatography-mass spectrometry selected ion chromatogram of volatile halogenated hydrocarbons in furniture (1. RT 4.29, carbon tetrachloride; 2. RT 5.06, dichloromethane; 3. RT 5.50, chloroform; 4 . RT 6.05, 1,1-dichloroethane; 5. RT 6.61, 1,1,1-trichloroethane; 6. RT 7.78, trichloroethylene; 7. RT 8.66, dichloropropene; 8. RT 9.29, tetrachloroethylene; 9. RT 11.61, chlorobenzene; 10. RT 12.85, α-chlorotoluene; 11. RT 20.56, 1,3-dichlorobenzene; 12. RT 20.58, 1,4-dichlorobenzene Benzene; 13. RT 20.76, 1,2-dichlorobenzene; 14. RT 23.13, 1,2-dibromo-3-chloropropane; 15. RT 25.27, α, α-dichlorotoluene, RT is retention time) ;

Figure 4 is a gas chromatography-mass spectrometry selected ion chromatogram of volatile terpenes in furniture (1. RT 17.81, α-pinene; 2. RT 18.47, camphene; 3. RT 19.79, β-pinene; 4. RT 20.43, mercene; 5. RT 21.52, carene; 6. RT 22.28, limonene; 7. RT 27.00, terpineol; 8. T 31.50, longifene; 9. RT 31.59, cedrene; 10 . RT31.60, cedarene; 11. RT 31.64, syringene; 12. RT 31.83, cypressene, RT is retention time);

Figure 5 is the selected ion chromatogram of volatile alkanes in furniture (1. RT 5.80, 3-methylpentane; 2. RT 6.04, n-hexane; 3. RT 7.18, cyclohexane; 4. RT RT 8.18, n-heptane; 5. RT 8.82, methylcyclohexane; 6. RT 11.69, n-octane; 7. RT 21.32, n-decane; 8. RT 25.03, n-undecane; 9. RT 27.57 , n-dodecane; 10. RT 31.13, n-tetradecane; 11. RT 33.80, n-hexadecane, RT is retention time);

Figure 6 is a gas chromatography-mass spectrometry selected ion chromatogram of volatile esters in furniture (1. RT 5.06, methyl acetate; 2. RT 5.59, vinyl acetate; 3. RT 6.00, ethyl acetate; 4. RT 6.88 , isopropyl acetate; 5. RT 7.60, ethyl acrylate; 6. RT 8.09, propyl acetate; 7. RT 8.36, butyl formate; 8. RT 10.02, isobutyl acetate; 9. RT 11.50, acetic acid Butyl ester; 10. RT 13.67, ethyl 2-methoxy-1-methyl; 11. RT 15.08, butyl acrylate; 12. RT 25.96, 2-ethylhexyl acetate; 13. RT 27.82, 2-ethylhexyl acrylate, RT is retention time);

Figure 7 is a gas chromatography-mass spectrometry selected ion chromatogram of other volatile organic compounds in furniture (RT 9.42, N,N-dimethylformamide, RT is retention time).

Detailed ways

Standard gas: use a gas dilution device to dilute the standard gas with high-purity nitrogen to 10nmol/mol;

Internal standard gas: monobromo-chloromethane, 1,2-difluorobenzene, chlorobenzene-d5 with a concentration of 100 nmol/mol.

In the embodiment of the present invention, nitrogen is high-purity nitrogen with a purity of not less than 99.999%, and helium is high-purity helium with a purity of not less than 99.999%.

The gas chromatography-mass spectrometer (GC/MS) used in the embodiment of the present invention is equipped with a mass selective detector; the atmospheric pre-concentrator has the functions of automatic quantitative sampling and automatic addition of standard gas and internal standard; the maximum dilution of the gas diluter The multiple can reach 1000 times, the concentrator automatic sampler; the tank cleaning device can evacuate the sampling tank to vacuum (<10Pa), and has the functions of heating, humidification, and pressure cleaning. Summa tank: a stainless steel sampling tank with an inert inner wall, with a volume of 6L and a pressure resistance value of >241kPa. The flow controller is used in conjunction with the Summa tank; the calibrated flowmeter can accurately control the flow, and the pore size of the filter is ≤10μm.

The internal standard standard gas used in Example 1 of the present invention is monobromo-chloromethane, 1,2-difluorobenzene, and chlorobenzene-d5 with a concentration of 100 nmol/mol.

The analytical conditions of the atmospheric pre-concentrator in the following examples are:

First-stage cold trap: trapping temperature: -150 ℃; trapping flow rate: 100 mL/min; desorption temperature: 10 ℃; valve temperature: 100 ℃; baking temperature: 150 ℃; baking time: 15 min;

Secondary cold trap: trapping temperature: -15 °C; trapping flow rate: 10 mL/min; trapping time: 5 min; desorption temperature: 180 °C; desorption time: 3.5 min; baking temperature: 190 °C; baking Time: 15 min;

Three-level focusing: focusing temperature: -160 °C; analysis time: 2.5 min; baking temperature: 200 °C; baking time: 5min;

Transfer line temperature: 120°C.

GC-MS conditions: a) Quartz capillary column: the polarity index is less than 10, the column length is 50m-60m, the inner diameter is 0.25 mm, and the film thickness is 0.25 µm;

b) Heating program: 40 °C, hold for 1 min, then heat up to 100 °C at a rate of 3 °C/min, then heat up to 250 °C at a rate of 10 °C/min, hold for 10 min;

c) Carrier gas: high-purity helium, purity ≥99.999%, flow rate 1.2 mL/min;

d) Chromatography-mass spectrometry interface temperature: 260 ℃;

e) Ion source: electron ionization source EI, ion source temperature 230 ℃;

f) Ionization energy: 70 eV;

g) Mass analyzer: quadrupole mass analyzer;

h) Mass scanning range: (25~450) amu;

i) Scan Mode: Select full scan mode.

Example 1

1. Preprocessing

The furniture should be placed in the style most conducive to the release of harmful substances, and the whole piece should be pretreated. The surface should be exposed to the pretreatment environment as much as possible. The pretreatment time is 120h, and the environmental conditions of pretreatment are: temperature 23±2 ℃, the relative humidity is 45±10%, the distance between samples is not less than 300mm, the formaldehyde concentration between samples is less than 0.10mg/m3, and the TVOC concentration is less than or equal to 0.60mg/m3.

2. VOC collection

Select a climate chamber with a load-bearing rate of 0.15 and an air exchange rate of 1; collect the air in the chamber within 1 hour before the furniture samples are placed in the climate chamber, measure and record formaldehyde, benzene, toluene, and xylene ≤0.005mg/m3, TVOC≤0.05 mg/m3;

Put the pretreated furniture into the climate chamber to carry out the experiment. The furniture samples are sampled after being placed in the climate chamber for 20 hours, and the sampling time is 1±0.5h; the conditions of the climate chamber are: temperature 23±2℃, relative humidity 45±10 %, the air replacement rate is 0.5±0.05 times/h: the air flow rate is 90mL/min, the concentration of formaldehyde, benzene, toluene, xylene, and TVOC in the injected air: formaldehyde≤0.006mg/m ³ , single VOC≤0.0056mg/ m ³ , TVOC≤0.05mg/m ³ .

3. Suma Tank Sampling

The Summa tank is cleaned with a tank cleaning device before use. During the cleaning process, the Summa tank is humidified to reduce the active adsorption of the tank body. The cleaning temperature is 80 °C. After cleaning, the Summa tank is evacuated to a vacuum. (<10Pa), stand-by;

Connect the cleaned and evacuated Summa tank to the climate chamber. After installing the flow controller and filter, open the Summa tank valve and start constant current sampling. After the sampling time corresponding to the constant current flow rate of 90mL/min is reached , close the valve, and seal it with a seal;

Use a vacuum pressure gauge to measure the pressure inside the Summa tank. If the tank pressure is less than 83kPa, pressurize it with high-purity nitrogen to 101kPa. The dilution ratio of the collected furniture volatile gas is the difference between the diluted tank pressure and the tank pressure before dilution. ratio;

Calculate the dilution factor according to formula (1):

In the formula: f——dilution factor, dimensionless;

X _a — tank pressure before dilution, kPa;

Y _a — tank pressure after dilution, kPa;

[The volatile gas collected in the Summa tank can be detected immediately, or it can be stored at room temperature for detection and analysis within 20 days.

4. Determination of blank samples

Connect the cleaned and evacuated Suma tank to the gas dilution device, open the high-purity nitrogen valve, and close the Suma tank valve and the nitrogen tank valve when the pressure of the Suma tank reaches 101kPa. Take 400 mL of blank sample, concentrate by atmospheric pre-concentrator, and analyze by GC-MS.

5. Plot the standard curve

Use the gas concentration cold trap concentrator to extract 50mL, 100mL, 200mL, 400mL, 600mL, and 800mL of standard gas for use, and add 50mL of standard gas for internal standard use at the same time. The standard series of mol, 5.0nmol/mol, 10.0nmol/mol, 15.0nmol/mol, 20.0nmol/mol, the internal standard concentration is 12.5nmol/mol, from low concentration to high concentration in order to measure in GC-MS ;

Calculate the relative impact factor of the target according to formula (2), and calculate the average relative impact factor (RRF) of all standard concentration points of the target according to formula (3);

In the formula: RRF——the relative response factor of the target, dimensionless;

A _x ——the quantitative ion peak area of the target compound;

A _{is ——the} quantitative ion peak area of the internal standard compound;

ψ _is ——the mole fraction of the internal standard compound, nmol/mol;

ψ _x — mole fraction of target compound, nmol/mol;

In the formula: RRF——the average relative response factor of the target, dimensionless;

RRF _i - the relative response factor of the i-th target in the standard series, dimensionless;

n——Standard series points.

6. Sample Analysis

Connect the sample gas in the diluted Summa tank to the gas concentrating cold trap concentrator, take 400mL of the diluted gas in the Summa tank, add 50mL of the internal standard standard gas with a concentration of 100nmol/mol, and concentrate the atmospheric pre-concentrator. , and detected by GC-MS after concentration.

7. Qualitative Analysis

The measurement is carried out in a full scan mode, and the relative retention time of the target in the sample, the abundance ratio between the auxiliary qualifier ion and the quantitative ion, and the comparison of the target in the standard are used for characterization. The relative retention time of the target compound in the sample should be within ±3.0 % of the relative retention time of the compound in the calibration series. The relative deviation of the auxiliary qualifier ion and quantitative ion peak area ratio (Q sample) of the target compound in the sample and the auxiliary qualifier ion and quantification ion peak area ratio (Q standard) of the standard series of target compounds is controlled within ±30%;

Calculate the relative retention time of the target according to formula (4):

In the formula: RRT——relative retention time of target compound, dimensionless;

RT _c — retention time of target compound, min;

RT _is — retention time of internal standard, min;

Calculate the average relative retention time (RRT) according to formula (5): the average relative retention time of the same target compound in the standard series;

In the formula: RRT——the average relative retention time of the target, dimensionless;

RRT _i - the relative retention time of the i-th target in the standard series, dimensionless;

n——Number of standard series points;

Calculate the peak area ratio of auxiliary qualifier ion and quantitative ion according to formula (6)

In the formula: Q——the peak area ratio of auxiliary qualifier ion and quantitative ion;

_{At ——quantitative} ion peak area;

A _q ——Auxiliary qualifier ion peak area.

8. Quantitative Analysis

The average relative response factor is used for quantitative calculation, and the quantitative ions of the target and the corresponding relationship between each target and the internal standard refer to Appendix C. The content of the target substance (μg/m3) in the sample was calculated according to formula (7).

In the formula: ρ——the concentration of the target substance in the sample, μg/m ³ ;

A _x - the quantitative ion peak area of the target in the sample;

A _is - the quantitative ion peak area of the internal standard in the sample;

ψ _is ——the mole fraction of the internal standard in the sample, nmol/mol;

RRF - the average relative response factor of the target, dimensionless;

f ——dilution factor, dimensionless;

M——the molar mass of the target substance, g/mol;

22.4 — Molar volume of gas in standard state (273.15 K, 101.325 kPa), L/mol.

The detection method in Example 1 is suitable for qualitative and quantitative analysis of one or more volatile organic gases in furniture. The list of target volatile organic compounds in furniture is shown in Tables 1 to 8. The target volatile organic compounds in furniture (standard substances) ) chromatograms and retention times are shown in Figures 1-7.

method properties

The detection limit

The detection limits, quantification limits and linear ranges of volatile organic compounds in furniture are shown in Table 9-15.

Precision

The absolute difference between the two independent test results obtained by the same operator using the same equipment, according to the same test method, and independently of each other on the same test object in a short period of time in the same laboratory is not greater than the two determinations 10% of the arithmetic mean of the values, provided that it does not exceed 5% if it is greater than 10% of the arithmetic mean of the two measured values.

Repeatability

The relative deviation of the two determination results of the same operation was less than 10%.

Table 1 List of target benzene-based volatile organic compounds in furniture

Table 2 List of target alcohol volatile organic compounds in furniture

Table 3 List of target halogenated hydrocarbon volatile organic compounds in furniture

Table 4 List of target terpene volatile organic compounds in furniture

Table 5 List of target alkane volatile organic compounds in furniture

Table 6 List of target aldehyde and ketone volatile organic compounds in furniture

Table 7 List of target ester volatile organic compounds in furniture

Table 8 List of other volatile organic compounds in furniture

Table 9 Detection limit, quantification limit and linear range of volatile benzene series in furniture

Table 10 Detection limits, quantification limits and linear ranges of volatile alcohols in furniture

Table 11 Detection limit, quantification limit and linear range of volatile halogenated hydrocarbons in furniture

Table 12 Detection limits, quantification limits and linear ranges of volatile terpenes in furniture

Table 13 Detection limits, quantification limits and linear ranges of volatile alkanes in furniture

Table 14 Detection limits, quantification limits and linear ranges of volatile esters in furniture

Table 15 Detection limits, quantification limits and linear ranges of other volatile compounds in furniture

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Claims (10)

1. The method for detecting the volatile organic compounds in the furniture is characterized in that the furniture to be detected is placed in a climate chamber, the released volatile organic compounds are collected into a vacuum Suma tank, and the volatile organic compounds in the Suma tank are concentrated and then transferred to a gas chromatograph-mass spectrometer for detection.

2. The detection method according to claim 1, characterized in that the detection method comprises the following steps:

(1) placing furniture to be detected in a climate chamber, and sampling after 20 +/-0.5 h, wherein the sampling time is 1 +/-0.5 h;

(2) connecting the cleaned and vacuumized suma tank with a climate chamber, carrying out constant-flow sampling on volatile organic gas, and after sampling is finished, pressurizing and diluting the volatile organic gas by using high-purity nitrogen to enable the pressure in the suma tank to reach 101 kPa;

(3) transferring volatile gas in the Suma tank into a cold trap concentrator for concentration, adding internal standard gas for use, and detecting the gas by using a gas chromatograph-mass spectrometer after the gas is concentrated.

3. The detection method according to claim 2, wherein the furniture is pre-treated before being placed in the climate chamber, the pre-treatment method is to assemble the furniture according to a pattern which is most beneficial to the release of harmful substances, the pre-treatment time is 120 plus or minus 2h, the temperature is 23 plus or minus 2 ℃, the relative humidity is 45 plus or minus 10 percent, the distance between samples is less than 300mm, and the concentration of formaldehyde between samples is less than or equal to 0.10mg/m³The TVOC concentration is less than or equal to 0.60mg/m³。

4. The detection method according to claim 2, wherein the load-bearing rate of the climate chamber in the step (1) is 0.075-0.3, the temperature is 23 ± 2 ℃, the relative humidity is 45 ± 10%, and the aldehyde concentration in the feeding air is less than or equal to 0.10mg/m³The TVOC concentration is less than or equal to 0.60mg/m³(ii) a Humidifying and cleaning the Suma tank in the step (2) before use, wherein the cleaning temperature is 80 ℃,after the cleaning, the vacuum is pumped.

5. The detection method according to claim 2, wherein the internal standard gas is one or more of monochloromethane monobromo, 1, 2-difluorobenzene and chlorobenzene-d 5.

6. The detection method according to claim 2, wherein the amount of the volatile gas in the suma tank transferred to the cold trap concentrator in the step (3) is 50-1000 mL; the internal standard used gas concentration was 100 nmol/mol.

7. The detection method according to claim 6, wherein the amount of sample volatile gas in the suma tank transferred to the cold trap concentrator is 400 mL.

8. The detection method according to claim 2, wherein the size of the suma tank is 6L, the sampling flow rate is 90mL/min, and the sampling time is 1 hour.

9. The detection method according to claim 2, wherein the collection conditions of the cold trap concentrator are as follows: the trapping temperature of the primary cold trap is-150 ℃, the trapping flow rate is 100mL/min, the desorption temperature is 10 ℃, the valve temperature is 100 ℃, the baking temperature is 150 ℃, and the baking time is 15 min; the trapping temperature of the secondary cold trap is-15 ℃, the trapping flow rate is 10mL/min, the trapping time is 5min, the resolving temperature is 180 ℃, the resolving time is 3.5min, the baking temperature is 190 ℃, and the baking time is 15 min; the third-stage focusing temperature is-160 deg.C, the resolving time is 2.5min, the baking temperature is 200 deg.C, and the baking time is 5 min;

the gas chromatography-mass spectrometry conditions are as follows: heating a quartz capillary chromatographic column with a polarity index of less than 10 by a program at 40 ℃ for 1min, heating to 100 ℃ at 3 ℃/min, heating to 250 ℃ at 10 ℃/min, and keeping for 10min, wherein the carrier gas is helium and the flow rate is 1.2 mL/min; the chromatography-mass spectrometry interface temperature is 260 ℃; the ion source is an electron ionization source and the temperature is 260 ℃; ionization energy is 70 eV; the mass analyzer is a quadrupole mass analyzer; the mass scanning range is 25-450 amu; the scanning mode is a full scanning mode.

10. The detection method of claim 2, wherein the detection method is used for qualitative and quantitative analysis of volatile organic compounds in furniture.

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