Detection and Estimation of Special Marker for Rice Syrup (SMR) in Honey

Importance of the Topic

Adulteration of honey with sugar syrups, including rice syrup, poses significant challenges to product authenticity, consumer safety, and regulatory standards. The detection of 2-acetylfuran-3-glucopyranoside (SMR) offers a specific marker for rice syrup contamination, making sensitive analytical approaches crucial for safeguarding honey quality in commercial and research settings.

Objectives and Study Overview

The primary aim of this work was to develop and validate a reliable LC-MS/MS protocol using the Agilent 1260 Infinity II LC system coupled with the Ultivo triple quadrupole mass spectrometer to quantify SMR in honey at trace levels. This application note demonstrates method optimization, performance metrics, and real sample analysis to meet routine testing requirements.

Methodology and Instrumentation

The sample preparation involves a simple liquid-liquid extraction of 1 g homogenized honey diluted with water, followed by centrifugation and 0.22 µm filtration. Chromatographic separation was performed on an InfinityLab Poroshell 120 EC-C18 column (2.1×150 mm, 4 µm) using a water/acetonitrile gradient (both containing 0.1% formic acid) at 500 µL/min and 40 °C. Mass spectrometric detection employed the Ultivo LC/TQ in positive AJS ionization mode monitoring MRM transitions 311.1→148.9 (quantifier) and 311.1→185.0 (qualifier), with key parameters including 50 psi nebulizer gas, 10 L/min drying gas at 300 °C, 11 L/min sheath gas at 300 °C, 4 kV capillary voltage, 1.5 kV nozzle voltage, 80 V fragmentor voltage, and 100 ms dwell time.

Main Results and Discussion

The method showed linearity from 0.005 to 0.25 mg/kg (R²=0.995) and achieved an LOQ of 0.005 mg/kg, 200-fold lower than the FSSAI threshold. Precision at low and high QC levels (six replicates each) yielded %RSD below 5% and recoveries between 70–120%. SMR eluted at approximately 2.9 min with clear distinction from blank matrix. Analysis of ten commercial honey samples detected SMR in three samples, two above the calibration range and one within.

Benefits and Practical Applications

This streamlined LC-MS/MS approach offers high sensitivity, rapid throughput, and cost-effectiveness, making it ideal for routine screening of honey adulteration. It aligns with EU, US, and Indian regulations and supports quality assurance in food manufacturing and regulatory laboratories.

Future Trends and Possibilities

Future developments may include coupling with isotopic-ratio mass spectrometry for enhanced confirmation, further miniaturization of triple quadrupole systems, automated sample handling for higher throughput, and advanced data analysis using machine learning for improved screening efficiency.

Conclusion

The Agilent 1260 Infinity II LC system coupled with the Ultivo LC/TQ provides a robust, sensitive, and reproducible method for detecting the rice syrup marker SMR in honey. Its performance meets stringent regulatory requirements and facilitates effective quality control to combat honey adulteration.

Used Instrumentation

• Agilent 1260 Infinity II Quaternary Pump (G7104C)
• Agilent 1260 Infinity II Vialsampler (G7129C)
• Agilent 1260 Infinity II Multicolumn Thermostat (G7116A)
• Agilent Ultivo Triple Quadrupole LC/MS with AJS Ion Source (G6465B)
• InfinityLab Poroshell 120 EC-C18 Column, 2.1×150 mm, 4 µm

References

1. Bing D. et al. Rapid Screening of Multiclass Syrup Adulterants in Honey by Ultrahigh-performance Liquid Chromatography/Quadrupole Time of Flight Mass Spectrometry. Journal of Agricultural and Food Chemistry 2015, 63, 6614–6623.
2. Wahab R. A. S., Syed Yaacob S. N., Ghoshal S. K. Detection Techniques for Adulterants in Honey: Challenges and Recent Trends. Journal of Food Composition and Analysis 2019, 80, 16–32.
3. Food Safety and Standards Authority of India. Method of Detection of 2-Acetylfuran-3-Glucopyranoside (2-AFGP)/3-O-α-D-Glucosyl Isomaltol, the Specific Marker for Rice Syrup by LC-MS/MS. File no. 11023/53/2018-QA.
4. SANTE/12682/2019. Analytical Quality Control and Method Validation Procedures for Pesticide Residues Analysis in Food and Feed. European Commission.