Liquid chromatography detection method for chlorphenesin in toy material
Technical Field
The invention belongs to the field of analytical chemistry, and particularly relates to a liquid chromatography detection method for chlorphenesin in toy materials.
Background
Liquid or viscous toys such as modeling clay, finger painting pigment, etc. are toys specially designed for children, and are used for modeling or painting by dipping with hands or fingers. The children have poor self-control force ratio and weak health consciousness, and when the children use and play the toys, the children carelessly touch the oral cavity through fingers, toxic and harmful substances in the toys can enter the bodies of the toys, so that the physical and psychological health of the children is seriously damaged.
The chlorphenesin is white to off-white crystal powder, is a broad-spectrum bacteriostatic agent and preservative, and has good bacteriostatic and bactericidal effects on microorganisms such as escherichia coli, staphylococcus aureus, pseudomonas aeruginosa, mould and the like. Currently, chlorphenesin is approved as a preservative in cosmetics, but studies have shown that chlorphenesin may cause infants to breathe quickly, and therefore infants are advised not to use products containing chlorphenesin, as described in europe under "part 7 of toy safety: finger print color-requirement and determination methods" and in domestic GB 6675.14-2014 "part 14 of toy safety: the requirements and test methods for the pigment for finger painting permit the use of chlorphenesin as a limited preservative, and the maximum permitted use concentration is specified to be 0.15%.
At present, no detection method for chlorphenesin serving as a preservative in liquid or viscous toys is available at home and abroad, and no detection literature report of related chlorphenesin is available.
Disclosure of Invention
Aiming at the problem that a detection method of the preservative chlorphenesin in liquid or viscous toys does not exist at home and abroad, the invention provides a liquid chromatography detection method of chlorphenesin in toy materials, and the method has the advantages of high accuracy and good reproducibility.
The technical scheme adopted by the invention is as follows:
a liquid chromatography detection method for chlorphenesin in toy materials comprises the following steps:
(1) preparing standard solution and fitting standard curve equation
Weighing 0.05g (accurate to 0.0001g) of chlorphenesin, adding methanol-water (50:50, v/v), ultrasonically dissolving, transferring to a 50mL volumetric flask, fixing the volume to a scale with the methanol-water solution, shaking up, and preparing into a standard stock solution with the mass concentration of 1000 mg/L;
transferring a standard stock solution of 1000mg/L into a volumetric flask of 5.0mL to 100mL, fixing the volume to a scale with a methanol-water (50:50, v/v) solution, shaking up to prepare an intermediate working standard solution with the mass concentration of 50 mg/L;
transferring 0.20 mL, 1.00 mL, 2.00 mL and 10.0mL of chlorphenesin intermediate working standard solution and 1.00 mL, 2.50 mL and 5.00mL of standard stock solution into a 10mL volumetric flask, diluting the volumetric flask to a scale with methanol-water (50:50, v/v), and shaking up to obtain series concentration standard solutions with mass concentrations of 1.00, 5.00, 10.0, 50.0, 100, 250 and 500 respectively;
linear regression was performed with the peak area as ordinate (Y) and the mass concentration in the standard solution as abscissa (X) to obtain a regression equation of chlorphenesin of Y4.11 (e +003) X-1.46(e + 004).
(2) Sample processing
Weighing 1.0g (accurate to 0.0001g) of sample in a 10mL colorimetric tube with a plug, adding an extracting solution (methanol-water (50:50, v/v)) to a scale, sealing with a sealing film, carrying out vortex shaking for 1.0min, carrying out ultrasonic extraction for 20-35min, filtering with a 0.22 mu m filter membrane, and taking the filtrate as a sample solution to be detected for later use;
(3) chromatographic detection
Performing gradient elution by using methanol-water as a mobile phase, using a C-18 column as a chromatographic column (100mm multiplied by 2.1mm, 1.7 mu m), using a photodiode array (PDA) detector to detect the wavelength of 280nm (the detection wavelength of chlorphenesin), the flow rate of 0.2mL/min, the column temperature of 30 ℃, the sample injection amount of 1 mu L, and substituting the detected peak area into the regression equation in the step (1) to obtain the mass concentration of chlorphenesin in the sample.
Further, in the step (3), the gradient elution process with methanol-water as a mobile phase comprises the following steps: the volume ratio of the methanol to the water is 1:9 during 0-1 min, the volume ratio of the methanol to the water is 3:7 during 1-5 min, and the volume ratio of the methanol to the water is 1:1 during 5-10 min.
The invention has the beneficial effects that:
the method adopts methanol as an extraction solvent, and after ultrasonic extraction, volume fixing and filtration, the method adopts methanol-water as a mobile phase, performs gradient elution at the flow rate of 0.2mL/min, adopts a C-18 column as a chromatographic column, adopts a photodiode array (PDA) detector, has the detection wavelength of 280nm of chlorphenesin, and has the detection limit of 0.5ng (calculated by 3 times of signal to noise ratio).
The method for determining the content of the preservative chlorphenesin in the liquid or viscous toy material by using the methanol ultrasonic extraction-diode array-high performance liquid chromatography is established for the first time at home, the problem that no method for specially detecting the chlorphenesin exists in the field at home and abroad is solved, the method is simple and convenient to operate, low in detection limit and high in precision, is suitable for determining the content of the preservative chlorphenesin in the field, and has important significance for improving the quality level of the liquid or viscous toy in China, protecting the rights of consumers of children and promoting the smooth export of the toy product. Besides, the method also has the advantages of simple operation, high accuracy and good reproducibility.
Drawings
FIG. 1 is chromatograms of a standard solution and a test sample, (a) is a chromatogram of a chlorphenesin standard solution having a mass concentration of 250mg/L, and (b) is a chromatogram of a test sample.
Detailed Description
The application of the principles of the present invention will be further described with reference to the accompanying drawings and specific embodiments.
Example 1
Instruments and reagents:
waters H-class ultra high performance liquid chromatography (Waters corporation, USA) equipped with a Diode Array Detector (DAD) and an autosampler; ultrasonic cleaner (Branson corporation), ten thousandth electronic analytical balance (Beijing Sidoolis Co., Ltd.), Milli-Q Intergral water purifier (Millipore, France) Chlorobenzene glycol ether (purity 99.5%), methanol (chromatographic grade, Fisher corporation); ultrapure water (18.2 M.OMEGA.. multidot.cm).
A liquid chromatography detection method for chlorphenesin in toy materials comprises the following steps:
(1) preparing standard solution and fitting standard curve equation
Weighing 0.05g (accurate to 0.0001g) of chlorphenesin, adding methanol-water (50:50, v/v), ultrasonically dissolving, transferring to a 50mL volumetric flask, fixing the volume to a scale with the methanol-water solution, shaking up, and preparing into a standard stock solution with the mass concentration of 1000 mg/L;
transferring a standard stock solution of 1000mg/L into a volumetric flask of 5.0mL to 100mL, fixing the volume to a scale with a methanol-water (50:50, v/v) solution, shaking up to prepare an intermediate working standard solution with the mass concentration of 50 mg/L;
transferring 0.20 mL, 1.00 mL, 2.00 mL and 10.0mL of chlorphenesin intermediate working standard solution and 1.00 mL, 2.50 mL and 5.00mL of standard stock solution into a 10mL volumetric flask, diluting the volumetric flask to a scale with methanol-water (50:50, v/v), and shaking up to obtain series concentration standard solutions with mass concentrations of 1.00, 5.00, 10.0, 50.0, 100, 250 and 500 respectively;
linear regression was performed with the peak area as ordinate (Y) and the mass concentration in the standard solution as abscissa (X) to obtain a regression equation of chlorphenesin of Y4.11 (e +003) X-1.46(e + 004).
(2) Sample processing
Weighing 1.0g (accurate to 0.0001g) of sample in a 10mL colorimetric tube with a plug, adding an extracting solution (methanol-water (50:50, v/v)) to a scale, sealing with a sealing film, carrying out vortex shaking for 1.0min, carrying out ultrasonic extraction for 20-35min, filtering with a 0.22 mu m filter membrane, and taking the filtrate as a sample solution to be detected for later use;
(3) chromatographic detection
Gradient elution is carried out according to the table 1 by taking methanol-water as a mobile phase, a C-18 column is taken as a chromatographic column (100mm multiplied by 2.1mm, 1.7 mu m), a photodiode array (PDA) detector is used for detecting the wavelength of 280nm (the detection wavelength of chlorphenesin), the flow rate is 0.2mL/min, the column temperature is 30 ℃, the sample injection amount is 1 mu L, and the measured peak area is substituted into the regression equation in the step (1) to obtain the mass concentration of chlorphenesin in the sample.
TABLE 1 mobile phase gradient elution Table
Time
|
Flow rate mL/min
|
Methanol
|
Ultrapure water
|
0
|
0.2
|
10
|
90
|
1
|
0.2
|
30
|
70
|
5
|
0.2
|
50
|
50
|
10
|
0.2
|
50
|
50
|
12
|
0.2
|
10
|
90 |
In the range of (1.000-500) mg/L, the peak area and the mass concentration have good linear relation, and the correlation coefficient is 0.9995. The standard recovery rate of different levels is 98.3-104%, and the relative standard deviation (precision) is 0.51-2.13%.