GB/T 39765-2021 in English
VALIDDetermination of benzene,methylbenzene,ethylbenzene,dimethybenzene in stationery—Gas chromatographic method
- Issued on:2021-03-09
- Implemented on:2021-10-01
- File Format:PDF
- Delivery:Via email within 1~3 business days
$165.00
《GB/T 39765-2021文具中苯、甲苯、乙苯及二甲苯的测定方法 气相色谱法》由TC514（全国文具运动器材标准化技术委员会）归口，TC514SC1（全国文具运动器材标准化技术委员会文具分会）执行，主管部门为中国轻工业联合会。
Introduction
Technical background of the standard
With the increasing safety requirements for stationery, GB/T39765-2021 replaces the original detection method and uses gas chromatograph to accurately determine benzene series. The standard covers six major types of stationery products, including alteration and writing products, with a detection limit as low as 6-10mg/kg.
Comparison of core detection methods
| Technical parameters | This standard | Traditional method |
|---|---|---|
| Detector type | Flame ionization (FID) | UV spectrophotometry |
| Column type | 60m capillary column | Packing column |
| Separation efficiency | Complete separation of xylene isomers | Isomers cannot be distinguished |
Key operating points
Sample pretreatment case
For correction tape detection, the correction coating part needs to be taken, and then ultrasonic extraction for 15 minutes is performed and centrifuged. Actual tests show that 0.45μm polytetrafluoroethylene filter membrane can effectively avoid chromatographic column contamination.
Standard curve establishment
It is recommended to use a 6-point calibration curve (5-100μg/mL) with a correlation coefficient ≥0.995. Standard solutions of m/p-xylene should be prepared separately to ensure accurate quantification.
Implementation suggestions
- Select suitable solvents for different stationery types: ethyl acetate is recommended for oily products, and methanol is preferred for water-based products
- Regularly verify the separation of chromatographic columns, and the separation of o-/m-xylene should be ≥1.5
- Establish a blank control experiment to avoid interference from solvent background
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