Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D3270-13 – Standard Test Method Technical Guide
🔬 Scope and Applicability
These test methods describe the semiautomated procedure for determining total fluoride in various samples. They are applicable to fluoride-containing solutions where standards of identical composition have been carried through the same preparation procedures and have shown quantitative recovery. The method should not be used until applicability is demonstrated.
The procedure can detect 0.1 µg/mL of F, with a normal analysis range of 0.1 to 1.6 µg/mL of F. Higher concentrations can be analyzed by dilution with reagent water. For best accuracy, the fluoride concentration should fall in the middle or upper part of the calibration curve.
| 🟦 Parameter | 📏 Value |
|---|---|
| Detection Limit | 0.1 µg/mL F |
| Normal Range | 0.1 to 1.6 µg/mL F |
| Measurement Wavelength | 624 nm |
| Units | SI units standard |
For optimal accuracy, ensure sample concentrations fall within the mid to upper range of the calibration curve. Dilute samples exceeding 1.6 µg/mL F with reagent water.
⚙️ Test Method Principles
The semiautomated method incorporates microdistillation of the sample to isolate hydrogen fluoride (HF). The distillate reacts with alizarin fluorine blue-lanthanum nitrate reagent, forming a blue complex measured colorimetrically at 624 nm. Alternatively, a specific ion probe may be used for quantification.
This method is suitable for various sample types, including atmosphere and plant tissues, as long as proper preparation procedures are followed and validated for quantitative recovery.
📊 Referenced Standards and Safety
The method references several ASTM standards for sampling and analysis, including D1193 for reagent water, D1356 for terminology, D3266, D3267, D3268, D3269, and D3614 for laboratory practices. Users should consult these for detailed guidance.
Safety precautions are outlined in sections 8.3, 10.2.4, and 10.2.5. It is the user’s responsibility to establish appropriate safety, health, and environmental practices.
Users must demonstrate applicability before performing analyses. Ensure all safety precautions are followed as per the standard, including those in sections 8.3, 10.2.4, and 10.2.5.
❓ Frequently Asked Questions
🔍 What is the detection limit of the method?
The detection limit is 0.1 µg/mL of F, with a normal analysis range of 0.1 to 1.6 µg/mL of F.
💡 How can higher fluoride concentrations be analyzed?
Higher concentrations can be analyzed by careful dilution of samples with reagent water. Alternatively, the pump manifold can be modified to reduce sensitivity, but analyzing a smaller aliquot is recommended.
⚡ What is the principle of the semiautomated method?
The method is based on microdistillation of hydrogen fluoride (HF) from the sample, followed by reaction with alizarin fluorine blue-lanthanum nitrate reagent to form a blue complex measured at 624 nm, or using a specific ion probe.
📌 Which ASTM standards are referenced?
Referenced standards include D1193, D1356, D3266, D3267, D3268, D3269, and D3614.