Introduction

Rapid, non-destructive identification of unknown powders and suspected counterfeit pharmaceutical samples is important in forensic, pharmaceutical, and field-screening applications. Raman spectroscopy is well suited for this purpose because it can provide molecular fingerprint information with minimal sample preparation.
This application note describes the use of the JASCO PR-1w Palmtop Raman Spectrometer for the identification of controlled-substance mixtures and counterfeit pharmaceutical samples. The examples include a mixture containing cocaine, caffeine, and lidocaine; a counterfeit clonazepam sample containing lactose; and a fentanyl-containing mixture. The data was measured at the Instituto de Ciencias Forenses de Puerto Rico.

                                 Fig. 1 PR-1w Palmtop Raman Spectrometer

Experimental

Suspected controlled-substance and counterfeit pharmaceutical samples were analyzed using the JASCO PR-1w Palmtop Raman system. Raman spectra were collected directly from the samples and compared against reference spectral libraries using database-search algorithms.

Sample
Three representative samples were evaluated:
1.  Mixture of cocaine, caffeine, and lidocaine
2. Counterfeit clonazepam sample containing lactose
3. Fentanyl-containing mixture

Spectral identification was performed using library-search tools, mixture analysis, and targeted search methods where required.

Measured Protocol
The general measurement workflow was as follows:

1. Place the powder or sample material in the appropriate sample holder or vial holder.
2. Position the sample using the PR-1w accessory holder or Z-stage unit.
3. Acquire the Raman spectrum using the PR-1w Palmtop Raman spectrometer.
4. Process the spectrum using spectral-search software.
5. Compare the measured spectrum with controlled and prescription drug Raman spectral libraries.
6. For mixtures, apply suitable search algorithms such as first-derivative Euclidean distance and mixture-search analysis.
7. For samples with strong matrix interference, perform targeted analysis or spectral subtraction when required.
8. Confirm the presence of target compounds based on spectral match quality and interpretation of major Raman bands.

System
Instrument: JASCO PR-1w Palmtop Raman Spectrometer
Recommended configuration:

Parameters
The following analysis parameters were used or are recommended for this type of application:

Specific acquisition settings such as laser power, exposure time, accumulation number, and spectral range were not listed in the provided report and should be added when finalizing the validated method.

Keywords

Palmtop Raman, forensic analysis, controlled substances, counterfeit pharmaceuticals, cocaine, caffeine, lidocaine, clonazepam, lactose, fentanyl, targeted Raman search, KnowItAll database, mixture analysis

Results

Sample 1: Mixture of Cocaine, Caffeine, and Lidocaine
The Raman spectrum of Sample 1 was successfully analyzed as a multi-component mixture.
Using a search algorithm based on first-derivative Euclidean distance, the sample was identified as a mixture containing cocaine, caffeine, and lidocaine.
This result demonstrates that the PR-1w Palmtop Raman system can identify multiple components in a complex powder sample when paired with an appropriate spectral-search algorithm and reference database.

Fig. 2 Identification of Sample 1 mix of Cocaine, Caffeine, and Lidocaine

Sample 2: Counterfeit Clonazepam
Sample 2 was analyzed as a counterfeit clonazepam sample. Initial spectral interpretation indicated the presence of lactose, which can act as a major excipient and may mask weakerspectral features from the active pharmaceutical ingredient.

After lactose subtraction, clonazepam became detectable in the sample. This result shows the importance of spectral subtraction and mixture interpretation when analyzing counterfeit pharmaceutical samples. Even when the target compound is not the dominant component, Raman spectroscopy can support identification if the proper data-processing workflow is applied.

Fig. 3 Identification of Sample 2 Counterfeited Clonazepam

Sample 3: Fentanyl-Containing Mixture
Sample 3 was analyzed using a targeted search approach to determine whether fentanyl was present. Fentanyl was identified; however, the analysis was more challenging because the fentanyl concentration appeared to be low and fluorescence from other sample components interfered with the Raman signal.
This example highlights both the strength and limitation of Raman spectroscopy. The PR-1w system was able to support fentanyl identification, but low concentration and fluorescence interference can reduce spectral clarity. In such cases, targeted search methods, optimized acquisition conditions, and confirmatory laboratory testing may be required.

Fig. 4 Identification of Sample 3 mix of Fentanyl

Conclusion

The JASCO PR-1w Palmtop Raman Spectrometer successfully identified controlled and counterfeit-substance samples, including:
• A mixture of cocaine, caffeine, and lidocaine
• A counterfeit clonazepam sample containing lactose and clonazepam
• A fentanyl-containing mixture using targeted Raman analysis

These results demonstrate that palmtop Raman spectroscopy can be a useful rapid-screening tool for forensic and counterfeit pharmaceutical applications. The combination of portable Raman measurement, spectral libraries, mixture-search algorithms, and targeted analysis provides a practical workflow for identifying unknown or complex samples with minimal sample preparation.

References

Acknowledgement

This application was produced through the collaboration of the JASCO Incorporated application team and the Instituto de Ciencias Forenses de Puerto Rico.