GB/T 40189-2021
Determination of metronidazole and norfloxacin in toothpaste—High performance liquid chromatography method (English Version)
- Standard No.
- GB/T 40189-2021
- Language
- Chinese, Available in English version
- Release Date
- 2021
- Published By
- General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
- Latest
- GB/T 40189-2021
- Scope
- This standard specifies the high-performance liquid chromatography (HPLC) determination method for the content of banned antibiotics metronidazole and norfloxacin in toothpaste. This standard is applicable to the determination of the content of banned antibiotics metronidazole and norfloxacin in toothpaste. The detection limit of this standard method is 1mg/kg.
- Introduction
Technical background of the standard
With the increasing safety requirements for oral care products, this standard released in 2021 fills the gap in the detection of antibiotic residues in toothpaste. The standard uses high performance liquid chromatography combined with ultraviolet detection technology to simultaneously determine two common banned antibiotics, metronidazole and norfloxacin.
Core principles of the method
Technical elements Parameter requirements Technical significance Chromatographic column C18 stainless steel column (250mm×4.6mm×5μm) Ensure effective separation of the two antibiotics Detection wavelength 290nm Optimal UV absorption peak Mobile phase 0.1% phosphoric acid aqueous solution: acetonitrile (83:17) Optimize retention time and peak shape
Key Operation Points
Sample pretreatment: 0.1% formic acid aqueous solution-acetonitrile (95:5) was used as the extraction solution. After vortex oscillation and ultrasonic extraction, the centrifugal parameters (4000r/min×10min) must be strictly controlled to ensure the recovery rate.
Standard curve establishment: It is required to prepare a series of standard solutions of 50mg/L, 20mg/L, 10mg/L, and 5mg/L, and the correlation coefficient R≥0.9990.
Method Validation Data
Performance Indicators Technical Requirements Actual Performance Detection Limit 1mg/kg Meet Regulatory Requirements Recovery 85%-110% 5-100mg/kg Addition Range Precision RSD＜5% Repeat Determination Difference Control
Implementation Suggestions
1. class=instrument>pH meter needs to be calibrated regularly to ensure that the pH value of the mobile phase is accurately controlled in the range of 2.5-3.0
2. It is recommended to use diode array detector for spectral comparison to reduce the risk of false positives
3. Each batch of testing should include blank control and spike recovery experiments
GB/T 40189-2021 Referenced Document
- GB/T 6682 Water for analytical laboratory use.Specification and test methods
GB/T 40189-2021 history
- 2021 GB/T 40189-2021 Determination of metronidazole and norfloxacin in toothpaste—High performance liquid chromatography method