OSHA Method 60 for Volatile Amines Using Reversed-Phase Chromatography with Acclaim C30

Importance of the Topic

Volatile amines such as ethylenediamine, diethylenetriamine and triethylenetetramine pose significant occupational health risks due to their volatility and irritant properties. Accurate workplace monitoring is essential to ensure compliance with safety regulations and to protect workers from inhalation exposure.

Objectives and Overview

The primary objective is to evaluate a reversed-phase liquid chromatography method using Thermo Scientific™ Acclaim™ C30 columns for OSHA Method 60 analysis. This approach aims to improve separation efficiency, peak shape and detection limits compared to the conventional normal-phase technique.

Methodology

A standard air-sampling tube captures volatile amines, which are derivatized on-tube with 1-naphthyl isothiocyanate (NITC) to form UV-active thiourea derivatives. The sample is then eluted isocratically under reversed-phase conditions using methanol and 10 mM formic acid (85:15, v/v). Key chromatographic parameters include a flow rate of 0.425 mL/min, column temperature of 30 °C, injection volume of 1.0 µL and UV detection at 280 nm.

Used Instrumentation

• Column: Thermo Scientific™ Acclaim™ C30, 3 µm, 3×150 mm
• LC System: Thermo Scientific™ Dionex™ UltiMate™ 3000
• Mobile Phase: Methanol : 10 mM formic acid (85 : 15 v/v)
• Detector: Diode Array Detector (UV 280 nm)

Main Results and Discussion

• Complete baseline separation of the three NITC derivatives achieved within 6 minutes.
• Sharper peak shapes and reduced tailing compared to normal-phase LC, enhancing quantitation accuracy.
• Lower limits of detection facilitate trace-level monitoring of workplace air samples.

Benefits and Practical Applications

• Faster analysis time increases sample throughput in occupational hygiene laboratories.
• Improved chromatographic performance supports more reliable compliance testing.
• Method simplicity and robustness make it suitable for routine QA/QC and research environments.

Future Trends and Applications

Continued advancements in stationary phase technology and detector sensitivity may further lower detection limits and enhance multi-analyte capability. Integration with automated sampling and data processing platforms could streamline occupational monitoring workflows and expand applicability to other volatile hazards.

Conclusion

Reversed-phase chromatography on Acclaim C30 columns offers a superior alternative to traditional normal-phase LC for OSHA Method 60 analysis. The method delivers faster separations, better peak characteristics and enhanced sensitivity, improving the reliability of volatile amine monitoring in occupational settings.

Reference

• Thermo Fisher Scientific. OSHA Method 60 for Volatile Amines Using Reversed-Phase Chromatography with Acclaim C30 Columns. Application Note PB20617_E, October 2012.