GB/T 38904-2020 in English

Key points of sample pretreatment

The standard specifically stipulates the removal process of organic solvents: the burning condition of 1050℃ for 60 minutes can ensure the complete decomposition of organic carriers. The practice of a certain enterprise shows that the use of gradient heating method (200℃/h) can effectively prevent sample splashing and increase the recovery rate to 98.5%.

Quality control system

Establish a three-level calibration mechanism:

1. The working curve is verified every 3 months
2. The instrument must be recalibrated after maintenance
3. If the allowable difference of the standard material exceeds the limit, recalibrate immediately

Laboratory Configuration Plan

It is recommended that enterprises choose supporting equipment according to product characteristics:

• Conventional pigments: equipped with high frequency melting machine + wavelength dispersive X-ray fluorescence spectrometer
• Boron/lithium pigments: additionally equipped with ICP-OES and gold crucible set
• R&D laboratories: it is recommended to add laser particle size analyzer to assist sample pretreatment

Standard Application Case

After a ceramic ink manufacturer adopted this standard method:

• The detection time of cobalt element was shortened from 4h to 30min
• The data deviation between different laboratories was reduced from 1.2% to 0.3%
• Successfully passed the EU EN71-3 heavy metal migration test