Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D3558-15 – Standard Test Method Technical Guide
🧪 Overview of Test Methods for Cobalt Detection
ASTM D3558-15 (Reapproved 2023) provides standard test methods for the determination of dissolved and total recoverable cobalt in water and wastewater using atomic absorption spectrophotometry. These methods are designed to accommodate various concentration levels and water matrices, ensuring accurate and reliable results for environmental monitoring and compliance purposes.
⚙️ Test Procedures and Concentration Ranges
The standard outlines three distinct test methods, each suited for specific concentration ranges and sample types. The table below summarizes the key parameters:
| 🧪 Test Method | 📏 Concentration Range | 🌊 Typical Applications |
|---|---|---|
| Test Method A (Direct) | 0.1 mg/L to 10 mg/L | Reagent water, potable water, river water, wastewater |
| Test Method B (Chelation-Extraction) | 10 µg/L to 1000 µg/L | Reagent water, potable water, river water, sea water, brine |
| Test Method C (Graphite Furnace) | 5 µg/L to 100 µg/L | Reagent water, artificial seawater, river water, tap water, synthetic brine |
It is the analyst’s responsibility to validate these methods for other matrices not listed in the standard.
📊 Key Measured Properties and Precision
Most waters contain only trace concentrations of cobalt from natural sources, making sensitive detection methods essential. The standard emphasizes the use of atomic absorption spectrophotometry, with precision and bias evaluated in accordance with Practice D2777. The methods are applicable for both dissolved and total recoverable cobalt, where total recoverable cobalt is defined as the cobalt forms recovered in the acid-digestion procedure specified in these test methods.
💡 Tip: For samples with high salinity or complex matrices, Test Method B (Chelation-Extraction) is recommended due to its enhanced sensitivity and selectivity.
⚠️ Warning: Refer to sections 11.8.1, 21.12, and 23.10 for specific hazard statements. Always use appropriate safety equipment when handling reagents and samples.
❓ Frequently Asked Questions
🔍 What is the scope of ASTM D3558-15?
This standard covers the determination of dissolved and total recoverable cobalt in water and wastewater by atomic absorption spectrophotometry, with three test methods covering concentrations from 5 µg/L to 10 mg/L.
💡 Which test method is most sensitive for trace cobalt analysis?
Test Method C (Graphite Furnace) offers the highest sensitivity for concentrations from 5 µg/L to 100 µg/L, while Test Method B (Chelation-Extraction) is suitable for 10 µg/L to 1000 µg/L.
⚡ What safety precautions are mentioned in the standard?
Specific hazard statements are listed in sections 11.8.1, 21.12, and 23.10. Users must establish appropriate safety, health, and environmental practices before use.
📌 How is “total recoverable cobalt” defined?
Total recoverable cobalt is a descriptive term for the cobalt forms that are recovered during the acid-digestion procedure specified in these test methods.