Material ID through Dark Brown PV Bag

Importance of the Topic

Rapid, non‐invasive identification of materials through opaque or colored packaging is essential in pharmaceutical quality assurance, customs and border control, and industrial inspection. Raman spectroscopy that penetrates common polymer films enables secure verification of contents without compromising sample integrity.

Objectives and Study Overview

This application note evaluates the NanoRam® handheld Raman spectrometer (785 nm excitation) for identifying acetaminophen tablets through a dark brown polyvinyl (PV) bag. The goal is to demonstrate accurate library matching despite reduced signal intensity caused by the bag’s opacity and coloration.

Methodology and Instrumentation

Tests were conducted by positioning the standard shaft of the NanoRam directly against the outer surface of a 0.07 mm thick dark brown PV bag containing Tylenol tablets. Key operational parameters included:

• Laser power set to 50% to avoid thermal damage to the bag
• Minimum Hit Quality Index (HQI) threshold of 80
• Three individual hits per measurement
• Spectral range: 176–2500 cm⁻¹
• Comparison against the B&W Tek USP spectral library

Used Instrumentation

• NanoRam® handheld Raman spectrometer
• 785 nm laser excitation source
• Standard shaft accessory (point‐and‐shoot adaptor removed to increase beam spot size)

Key Results and Discussion

The measured Raman spectrum from the Tylenol tablet through the dark brown bag produced a lower intensity signal compared to measurements through transparent packaging. Despite this attenuation, the system achieved a match to acetaminophen with an HQI of 83.03. An overlay of the acquired spectrum against the library reference confirmed alignment of characteristic Raman bands, validating reliable identification under the tested conditions.

Benefits and Practical Applications

Non‐destructive content verification through colored packaging enhances safety and efficiency in:

• Pharmaceutical authenticity checks in manufacturing and distribution
• Regulatory inspections without opening sealed products
• Customs and security screening for controlled substances
• On‐site quality control in remote or field settings

Future Trends and Opportunities

Advancements may include improved signal‐processing algorithms to boost sensitivity through highly absorbing or fluorescent materials, expanded reference libraries for broader compound coverage, integration with AI for automated threat detection, and adaptation of the technique to thicker or multilayer packaging.

Conclusion

This study confirms that the NanoRam® handheld Raman spectrometer can accurately identify acetaminophen through a dark brown PV bag by optimizing laser power, measurement settings, and spectrometer configuration. The approach provides a fast, non‐destructive solution for secure material authentication in diverse analytical scenarios.

Reference

B&W Tek, LLC. Material ID through Dark Brown PV Bag Application Note (2014).