GB/T 40176-2021 in English

Standard technical background

With the popularization of functional oligosaccharides in the food industry, the demand for accurate detection of xylobiose as an important prebiotic ingredient has become increasingly prominent. The release of GB/T40176-2021 fills the gap in the detection standard of xylobiose in plant-derived products in my country. The use of hydrophilic retention chromatography combined with PMP derivatization technology significantly improves the detection sensitivity and specificity.

Method principle analysis

The core of this method is to use a high performance liquid chromatograph with a hydrophilic retention chromatography column to generate a stable ultraviolet absorption product by the derivatization reaction of the reducing end of xylobiose with PMP (1-phenyl 3-methyl 5-pyrazolone). Compared with traditional sugar detection methods, this technology has three major advantages:

Key operating points

Optimization of chromatographic conditions

The chromatographic parameters recommended by the standard have been verified by multiple laboratories:

• Column temperature of 40℃ can balance separation efficiency and column life
• Acetonitrile-0.1% phosphoric acid gradient elution effectively improves peak shape
• Detection wavelength of 250nm takes into account both sensitivity and baseline stability

Implementation suggestions

1. Preparation of standard: The standard stock solution of xylobiose needs to be stored at 4℃ in the dark. It is recommended to prepare the working curve freshly every week
2. Derivatization control: The water bath reaction time is strictly controlled at 100±2min, and the temperature fluctuation is ≤1℃
3. Quality control requirements: Each batch of samples should include blank spike recovery (80-110%) and continuous calibration verification (RSD＜5%)

Note: When testing low-content samples such as solid beverages, the sampling volume can be appropriately increased to 2g to improve detection reliability.