Agilent Molecular Spectroscopy Compendium

Significance of the topic

The analysis of foods and food ingredients for quality, authenticity, and safety is critical in an increasingly globalized supply chain. Molecular spectroscopy methods—particularly FTIR, UV-Vis, and fluorescence spectroscopy—offer rapid, non-destructive tools capable of detecting adulteration, verifying ingredients, and quantifying contaminants across the farm-to-fork continuum. These approaches reduce analysis time, minimize sample preparation, and enable on-site decision making for QA/QC in agriculture and food production.

Objectives and overview

This compendium presents a comprehensive survey of Agilent’s molecular spectroscopy solutions and applications for food analysis. Key goals include:

• Identifying target and non-target molecules in complex food matrices.
• Demonstrating portable, handheld, and benchtop FTIR systems for rapid screening and quantitative analysis.
• Reviewing UV-Vis and fluorescence spectrometers for nutrient and colorimetric measurements.
• Highlighting instrumental applications: from edible bird nest authentication to pesticide detection, acrylamide quantification, and hydroponics nutrient monitoring.

Methodology and instrumentation

Agilent spectrometers utilize state-of-the-art optomechanics, sampling accessories, and chemometric software to achieve sensitive, reliable results:

• Handheld FTIR: 4100 ExoScan (diffuse reflectance), 4200 FlexScan (single-reflection ATR).
• Portable FTIR: 4500 Series (battery-powered), 5500 Compact FTIR (field and mobile lab).
• Benchtop FTIR: Cary 630 FTIR (diamond ATR, DialPath transmission), Cary 610 FTIR Microscope.
• UV-Vis and Fluorescence: Cary 60 UV-Vis (high optical stability), Cary Eclipse Fluorescence (Xenon flash lamp).
• Chemometric models: Partial least squares regression (PLSR) for quantification; custom on-board library searches for qualitative identification.

Main results and discussion

Critical findings across multiple food-analysis studies include:

• Edible bird nest authenticity: handheld FTIR identified carbonate, salt, sugars, and MSG adulterants with clear spectral markers and on-board pass/fail methods.
• Tomato quality traits: PLSR models based on FTIR spectra predicted Brix, pH, titratable acidity, glucose, fructose, and citric acid with R ≥ 0.75, SEP < 0.5 g/100 g.
• Dairy powders, flours, sugars, tea, and milk: Cary 630 ATR-FTIR differentiated similar powders, authenticated botanical powders, and measured milk adulteration (e.g., whey, urea, peroxide) to < 1 g/L SEP.
• Pesticide screening: portable FTIR libraries rapidly identified prohibited organochlorines (chlordane, aldrin, lindane, campheclor) in < 1 min.
• Acrylamide in potato chips: PLSR on handheld FTIR matched LC-MS/MS with SEP ~75 µg/kg across 169–2453 µg/kg range.
• Hydroponics phosphorus: UV-Vis methods (vanadomolybdate at 470 nm, stannous chloride at 690 nm) quantified PO4-P at low mg/L levels with 0.1 mg/L accuracy.
• Leaf optical properties: Cary 500 spectrophotometer validated PROSPECT model for reflectance/transmittance of cereal leaves; model inversion retrieved water and pigment content with R2 > 0.9.

Benefits and practical applications

These spectroscopic platforms deliver:

• Rapid, non-destructive testing without extensive sample prep or consumables.
• Portable and benchtop solutions for in-field, at-dock, and lab-based QA/QC.
• Intuitive software (MicroLab) enabling unskilled operators to obtain reliable pass/fail or quantitative results.
• Decision support for accept/reject actions in ingredient receipt, process monitoring, and final product verification.

Future trends and applications

Anticipated directions include:

• Integration of handheld spectrometers with cloud-based chemometric models and real-time alerts.
• Advanced machine-learning algorithms for multi-analyte quantification and anomaly detection.
• Miniaturized sensors for smartphone-based analyses in remote agricultural settings.
• Expansion to emerging contaminants, specialty ingredients, and packaged-food screening workflows.

Conclusion

Agilent’s molecular spectroscopy toolkit—combining FTIR, UV-Vis, and fluorescence spectrometers with robust sampling technologies and chemometric software—provides versatile, high-throughput solutions for food and agricultural analysis. These methods complement traditional chromatographic techniques by offering rapid, on-site, and cost-effective approaches to ensure quality, safety, and regulatory compliance across the food supply chain.

Reference

Key publications and application notes:

• 5990-9789EN: Edible bird nest FTIR screening
• 5991-0003EN: In-situ tomato trait screening via FTIR
• 5991-0784EN: Dairy powder QA/QC using ATR-FTIR
• 5991-1405EN: FTIR family overview—lab results anywhere
• 5991-2532EN: Acrylamide measurement by portable FTIR
• SI-A-1121: Phosphorus determination in hydroponics solution