SN/T 4683-2016 in English

Technical Background of the Standard

This standard was developed to address the risk of formamide residues in ethylene-vinyl acetate (EVA) products. Formamide, a potential carcinogen, may remain in foamed EVA products. Its implementation in 2016 filled a gap in testing standards in this area in my country.

Comparison of Method Principles

Key Operation Points

Sample Preparation

Chop the sample into pieces smaller than 2mm×2mm and accurately weigh 0.2g±0.0001g. When using a Soxhlet extraction apparatus, maintain a reflux rate of 5-6 times/hour.

Instrument Parameters

A DB-WAX column (30m×0.25mm×0.25μm) is recommended. A temperature program is used: 50°C (1min) → 110°C (20°C/min) → 230°C (50°C/min, 5min). Mass spectrometry qualifier ions are m/z: 17/29/45, and quantifier ion is m/z: 45.

Implementation Recommendations

Quality Control

A blank test should be performed for each batch of samples, and the standard solution should be injected at an equal volume as the sample. Note that the formamide standard stock solution must be stored at 4°C away from light and is valid for 6 months.

Result Verification

When the test value is close to the lower limit of determination (10 mg/kg), it should be verified by the characteristic ion abundance ratio (17:29:45=7:27:100), and the deviation must be within the range specified in Table 1.