Sample Preparation of Cannabis Products by Syringe Filtration using the Shimadzu Cannabis Analyzer

Importance of the topic

Cannabis flower contains diverse cannabinoids and matrix components that can clog chromatographic systems, making efficient filtration critical for reliable potency testing.

• Prevents instrument fouling and downtime
• Ensures accurate potency determination for regulatory compliance
• Supports high-throughput testing in QA QC environments

Objectives and study overview

This study aimed to evaluate various syringe filter types for sample preparation of cannabis flower extracts prior to HPLC analysis using the Shimadzu Cannabis Analyzer method.

• Assess recovery and precision of six filter materials
• Compare extraction efficiency in spiked and unspiked sample sets
• Select an optimal filter balancing analytical performance and cost

Methodology

Four representative cannabis flower samples were extracted following the CAP HS protocol. Unfiltered aliquots were spiked with an 11-part cannabinoid mix at 10 ppm. Each sample was filtered in replicates of ten through 0.45 µm, 13 mm syringe filters of six types. Samples, calibration standards (0.5 to 100 ppm) and QC levels (20 and 80 ppm) were analyzed using a 10-minute HPLC method with UV detection.

Instrumentation used

• Shimadzu Cannabis Analyzer for Potency HS method
• Nexera XR HPLC system with NexLeaf C18 2.7 µm column and guard column
• UV detector at 220 nm
• Syringe filters: polypropylene, nylon, PTFE, PVDF hydrophilic, PVDF hydrophobic and PES

Main results and discussion

• Calibration curves achieved r2 of 0.999 or higher with RSD under 20%
• Spiked sample replicates showed %RSD below 1%; unspiked samples exhibited higher variability
• Polypropylene, nylon and PTFE filters provided stable recoveries around 97 to 100 percent with RSD of 1.5 to 2.5 percent
• PVDF hydrophilic showed greater variability; PES and PVDF hydrophobic were less consistent

Representative chromatograms confirmed baseline separation of 11 cannabinoids within 10 minutes.

Benefits and practical applications

• Reliable filtration prevents column blockages and reduces maintenance
• Consistent recoveries improve confidence in potency results
• Selecting nylon filters offers cost savings with performance close to polypropylene
• Method seamlessly integrates into routine QC workflows

Future trends and possibilities

• Advanced membrane materials for enhanced recovery and stability
• Automated inline filtration for higher throughput
• Coupling with mass spectrometry for broader compound profiling
• Microflow and high pressure approaches for even faster analysis

Conclusion

The evaluation identified polypropylene, nylon and PTFE SyrFi filters as optimal choices for cannabis potency testing on the Shimadzu system. While polypropylene yielded the best recoveries, nylon presents a cost-effective alternative. Adoption of these filters supports robust, accurate and efficient HPLC-based analysis in cannabis laboratories.

References

• Edwardsen J., Pezeshk N., Young C. Sample Preparation of Cannabis Products by Syringe Filtration using the Shimadzu Cannabis Analyzer. Shimadzu Scientific Instruments, Columbia, MD, USA.