Agilent AAQ65 Application Note: Use of Drierite Trap to Extend Lifetime of Vapor Generation Absorption Cell

About this manual

Vapor generation techniques for atomic absorption analysis often suffer from short quartz absorption cell lifespans due to devitrification and cracking. This issue is primarily caused by the carryover of alkaline substances, such as potassium iodide (KI), into the cell during arsine transport.

To address this, a drierite trap was installed between the gas/liquid separator and the absorption cell. The document details experimental results showing that while the trap introduces a delay in conditioning time, it significantly extends the operational life of the quartz cells without compromising analytical accuracy at higher concentrations.

What's inside

• Introduction
• Instrumentation and Typical Parameters
• Principle of Operation
• Results and Discussions
• Conclusion

Frequently asked questions

What causes the quartz absorption cell to devitrify?

Devitrification is caused by too much alkaline substance, such as KI, being carried over with the arsine gas and nitrogen into the absorption cell.

How does one know when to change the drierite trap?

The operator should change the drierite when two-thirds of it has been humidified by the alkaline substance, indicated by a color change from blue to pink.

Does using a drierite trap affect the number of routine analyses?

No, proper conditioning of the system with the trap does not significantly affect the number of routine analyses conducted in a given time.