Complete compilation of applications for food analysis

Significance of the Topic

Ensuring the safety and authenticity of dairy products is critical for public health and regulatory compliance. Concerns such as toxic contaminants (mycotoxins, dioxins, pesticide residues, heavy metals), undeclared allergens, and economic adulteration drive the need for sensitive, rapid, and reliable analytical methods. Modern food safety laboratories require high-throughput solutions capable of trace-level detection, accurate quantitation, and unambiguous confirmation across diverse matrices.

Objectives and Overview of Methods

• Screen and quantify emerging and regulated contaminants in milk, powdered formulas, and dairy-derived foods
• Detect undeclared allergens and economically motivated adulteration in dairy products
• Employ advanced chromatographic and mass spectrometric techniques for heightened sensitivity and selectivity
• Integrate simplified sample preparation (QuEChERS, immunoaffinity clean-up, microchip electrophoresis) to streamline workflows
• Demonstrate methods according to international guidelines and legislation (EU, US FDA, EPA)

Methodologies and Instrumentation

• HPLC–Fluorescence Detection: Quantitation of aflatoxin M1 in milk using RF-20AXS with post-column derivatization and immunoaffinity clean-up.
• UHPLC–MS/MS: Multi-residue pesticide screening (fipronil, neonicotinoids) in honey and eggs on LCMS-8060/8050 with QuEChERS extraction; rapid melamine analysis in powdered milk by LDTD-MS/MS.
• GC–MS/MS: Dioxin (PCDD/Fs) analysis in food and feed using GCMS-TQ8040 with Smart MRM for both ultra-trace quantitation and confirmation; PCB analysis by retention time-synchronized MRM.
• MultiNA Microchip Electrophoresis: Qualitative detection of allergenic proteins (egg, milk, wheat, shrimp, peanut, soy) via PCR amplicon separation in under 2 minutes per sample.
• Microchip-based Profiling (MALDI-TOF iDplus): Differentiation of milk species (cow, buffalo, goat) and detection of mozzarella adulteration through custom SuperSpectra databases and cluster analysis.
• ICP-MS and ICP-OES: Multi-element profiling of formula milk powder (Ca, Mg, Fe, Zn, harmful elements As, Pb, Cd, Cr) on ICPMS-2030 and ICP-9820 after microwave digestion.

Main Results and Discussion

• LOD/LOQ: 10 fg on-column for dioxins (PCDD/Fs), 0.1 µg/L for aflatoxin M1, sub-ppt levels for pesticides in complex matrices, sub-mg/kg for mineral oils in dry food.
• Linearity: R2 > 0.999 across required concentration ranges for all methods.
• Precision: intra- and inter-day RSD < 8 % for multi-residue MS/MS and GC/MS assays.
• Recoveries: 75–105  % for aflatoxins, 70–110  % for neonicotinoids, 80–120  % for mineral oils.
• Rapid sample throughput: 3.5 min LC–MS/MS runs for aminoglycosides, 4 min LC–MS/MS screening of pesticides, 80 s per sample MicroNA analysis.
• Specificity: MRM spectrum mode and Smart MRM confirm analyte identity, MALDI-TOF SuperSpectra unambiguously discriminate milk species.

Benefits and Practical Applications

• Compliance: Methods conform to EU, FDA, EPA standards for contaminants in milk and dairy.
• Speed & Sensitivity: High throughput with femtogram-level detection supports large-scale monitoring.
• Versatility: Single instruments handle multiple target classes (pesticides, mycotoxins, allergens, dioxins).
• Reduced Complexity: Simplified QuEChERS and immunoaffinity pre-treatments minimize manual steps.
• Economics: Eliminates need for multiple specialized instruments, reduces solvent and consumable use.

Future Trends and Potential Uses

Emerging research will focus on non-targeted screening approaches using high-resolution MS for unknown contaminant discovery, further miniaturization of sample introduction (microfluidics, ambient ionization), and advanced data analytics (machine learning) for predictive food safety assessments. Integration of portable MS and IoT connectivity will enable on-site, real-time testing in supply chains.

Conclusion

Comprehensive analytical solutions combining UHPLC, GC–MS/MS, microchip electrophoresis, and ICP techniques provide the sensitivity, selectivity, and speed required for modern dairy safety and authenticity testing. Coupled with simplified preparation workflows and advanced data processing, these methods empower laboratories to meet stringent regulatory demands and protect public health.

Reference

[1] K. Grob et al., "Food Addit. Contam." 8 (1991) 437
[2] I. Q. Khan, et al., "LC–MS/MS Determination of Melamine in Milk," Shimadzu Application Note, 2015