Cadmium (Cd), a highly toxic heavy metal with high mobility, non-biodegradability, and bioaccumulation, poses a significant threat to agricultural production and public health in China as it can enter the human body through the food chain from contaminated soil.
Traditional methods for detecting cadmium in soil and sediment, such as GB/T 17140 and GB/T 17141, are gradually becoming outdated in terms of sensitivity, accuracy, and automation, and are scheduled for repeal. While the current standard HJ 803-2016 can accurately detect cadmium, it still relies on complex acid digestion for sample pretreatment, which is time-consuming, labor-intensive, reagent-heavy, and prone to introducing errors or sample loss.
New standard of HJ 1426-2025
The HJ 1426-2025 “Soil and Sediment – Determination of Cadmium – Solid Direct Sampling/Graphite Furnace Atomic Absorption Spectrophotometry” standard provides a revolutionary solution. By applying solid direct sampling technology, it overcomes the major drawbacks of traditional methods. This reliable method, verified by 8 laboratories, is scheduled for official implementation on July 1, 2026.
Verified Excellence: Our Instrument at the Core
As a subsidiary of BIIC, BFRL is one of the eight verification laboratories. We actively participated in and completed the rigorous method validation process for this new standard.
Our next-generation WFX-220 Series Atomic Absorption Spectrophotometer is at the forefront of this technological leap. As early as 2022, it obtained a Chinese invention patent for a “Positioning Feed Device for Solid Samples” (ZL 2021 1 0013652.9), making it fully compatible with the solid direct sampling analysis required by the new standard.
Overcoming Challenges with Superior Technology
Applying solid direct sampling for graphite furnace atomic absorption analysis of cadmium presents challenges like complex background interference, precise control of ashing/atomization conditions, and a wide analytical range. The WFX-220 Series tackles these with:
- Exclusive Digital Temperature Control & Self-Correction: Supports multi-stage heating with free program editing. It ensures temperature control accuracy better than 1% and temperature reproducibility better than 0.5%.
- Outstanding Analytical Performance: For direct analysis of cadmium standard solutions (0-7 μg/L), a linearity of >0.999 and an RSD of <1.5% for a 7 μg/L standard were achieved, fully meeting practical requirements.
- Innovative Three-Gas Path System: Features independent control of internal, external, and mini gas flows. This innovation extends graphite tube life, enhances signal stability, and significantly expands the analytical range, enabling direct analysis of high-concentration cadmium in sediments up to 180 μg/L and beyond.
The Solid Direct Sampling Advantage
This technology allows for the direct introduction of simply prepared soil samples into the graphite furnace. With only minimal chemical pretreatment and the addition of a matrix modifier, accurate analysis is achieved. Compared to traditional methods, it is:
- Greener and More Environmentally Friendly
- Faster and More Convenient
- More Efficient and Accurate
By eliminating the digestion process, it avoids associated errors, reduces risks of sample loss and contamination, and dramatically improves analytical efficiency.
Post time: Mar-27-2026