Direct Identification of Packaged Substances using the Agilent Resolve Handheld Raman Analyzer

Importance of the Topic

Raman spectroscopy enables rapid, non-destructive chemical identification through packaging materials without sample preparation. Handheld Raman devices equipped with through-barrier capabilities extend this functionality by probing concealed substances in plastic, paper, or opaque containers. Such field-deployable solutions are vital for law enforcement, border security, and industrial quality control to detect illicit drugs, hazardous materials, or verify product authenticity on-site.

Study Objectives and Overview

This work evaluates the performance of the Agilent Resolve handheld Raman analyzer operating in conventional surface mode versus spatially offset Raman spectroscopy (SORS) through-barrier mode. Using granulated sugar (sucrose) as a proxy for a controlled substance, the study compares identification depth, library match accuracy, and analysis time through multiple layers of low-density polyethylene (LDPE) zip-lock bags, plastic wrap, and paper sachets.

Methodology and Instrumentation

Samples were prepared by placing sugar into a primary LDPE bag (60 μm thickness) and overlaying up to 69 additional LDPE bags of similar thickness (total up to 2.7 mm). Additional tests included cellophane wrap and paper sachets. A digital micrometer measured cumulative barrier thickness. The Agilent Resolve handheld Raman analyzer features an 830 nm NIR laser, choice of surface or SORS modes, built-in and user-customizable spectral libraries, and rugged design (IP67, shock-resistant). Mode selection in the accompanying software triggers either orthogonal excitation (surface) or dual-angle excitation (SORS).

Main Results and Discussion

In conventional surface mode, sucrose was accurately identified through up to 11 LDPE layers (~460 μm) with match percentages above 95%. Beyond this point, library matches shifted to polyethylene or wax components, indicating barrier interference. In SORS through-barrier mode, correct identification extended to 67 LDPE layers (~2.7 mm) within 2 minutes, with a transient match decline near 460 μm. The SORS technique proved effective despite increased haze and scattering at layer interfaces. Sugar in cellophane and in paper sachets yielded 100% and 98% sucrose matches respectively, demonstrating applicability to common drug-packaging materials. Prior studies also show SORS detection of ethanol through 21 mm of PET.

Benefits and Practical Applications

• Rapid, on-site screening of concealed materials in under 2 minutes.
• Non-destructive analysis eliminates need for sample preparation.
• Portable, user-friendly device suitable for law enforcement, customs, QA/QC, and industrial inspection.
• Flexible identification modes adapt to transparent, colored, or opaque barriers.

Future Trends and Applications

Advances may include expanded spectral libraries covering novel contraband and industrial formulations, integration with machine-learning algorithms for automated threat detection, and miniaturized multimodal sensors combining Raman with infrared or fluorescence. Enhanced laser excitation strategies could further increase penetration through composite or coated barriers. Applications will grow in pharmaceuticals, food safety, environmental monitoring, and secure supply chain verification.

Conclusion

The Agilent Resolve handheld Raman analyzer demonstrates robust identification of sugar as a model compound through multilayer LDPE packaging. SORS through-barrier mode extends detection depth by a factor of six compared to conventional surface mode, offering a powerful tool for rapid, non-invasive screening of concealed substances. This capability supports critical field applications in security, law enforcement, and industrial quality assurance.

References

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