Determination of MOSH Contamination in Baby Foods by Using LC-GC and LC-GC×GC-MS

Importance of the Topic

Mineral oil saturated hydrocarbons (MOSH) contamination in food, especially baby foods, is increasingly recognized as an important analytical target. Infants are more vulnerable to chemical residues due to higher intake per body weight and developing metabolic systems. Accurate detection of MOSH in baby food matrices is therefore essential for food safety monitoring and regulatory compliance.

Objectives and Study Overview

This study aimed to develop a rapid heart-cutting multidimensional LC–GC–FID method for quantifying MOSH in commercial solid baby food samples. Sixteen products covering fish-based, meat-based, and fruit-based formulations were analyzed. Qualitative confirmation of MOSH profiles was achieved by comprehensive two-dimensional GC–quadrupole MS (LC×GC–MS).

Methodology

Sample Preparation:

• Extraction: 500 mg of homogenized baby food extracted three times with hexane
• Filtration and Concentration: Combined extracts dried under nitrogen and diluted to 25% v/v in hexane
• Quantification: External calibration curve using mineral oil standards and manual integration of the MOSH hump

Chromatographic Analysis:

• LC–GC–FID: Heart-cutting LC on silica column with hexane mobile phase; transfer to GC2010 Plus with flame ionization detection
• LC×GC–MS: Collection of MOSH fraction and off-line analysis using Shimadzu GC×GC–QP2010 Ultra with cryogenic modulation

Used Instrumentation

• Shimadzu Prominence LC-20A system with photodiode array detector
• Shimadzu GC2010 Plus with Optic 3 PTV injector and FID
• Shimadzu GC×GC–QP2010 Ultra quadrupole mass spectrometer
• Cryogenic loop-type modulator for GC×GC

Main Results and Discussion

All samples contained MOSH, with levels ranging from 0.3 to 13.8 mg/kg. Fish-based samples showed highest contamination in one salmon product (13.8 mg/kg), exceeding the proposed 0.6 mg/kg limit for C10–C25 hydrocarbons. Meat-based products averaged 3.8 mg/kg, with varying hump profiles indicating different hydrocarbon distributions. Fruit-based formulations also exhibited MOSH, suggesting sources beyond vegetable oil, possibly from packaging or processing. Method validation demonstrated linear calibration (R2=0.9994), intra-day precision of 4.1% RSD, inter-day precision of 2.4% RSD, LOD of 0.6 mg/kg and LOQ of 2 mg/kg.

Benefits and Practical Applications

• Rapid screening of MOSH in complex food matrices with high throughput
• Improved separation of hydrocarbons from lipid matrices via LC heart-cutting
• Enhanced qualitative identification of hydrocarbon structures using GC×GC–MS
• Support for food safety monitoring and regulatory compliance in baby food production

Future Trends and Potential Applications

Advancements in comprehensive two-dimensional chromatography and high-resolution mass spectrometry will enable deeper profiling of hydrocarbon contaminants. Integration of inline LC×GC–MS and automated data processing could further reduce analysis time. Emerging regulations may drive the need for routine MOSH screening in various food categories and packaging materials.

Conclusion

The developed LC–GC and LC×GC–MS workflows provide robust, sensitive, and rapid approaches to detect and characterize MOSH in baby foods. Results highlight widespread contamination, underlining the need for routine monitoring and source control strategies.

Reference

• Grob K. et al. Food Addit Contam 8 (1991) 437
• Grob K. et al. J AOAC Int 74 (1991) 506
• Droz C. et al. Z Lebensm Unters Forsch 205 (1997) 239
• BMELV proposal on MOSH limit in food packaging migration
• Kitson FG, Larsen BS, McEwen CN. Gas Chromatography and Mass Spectrometry, Academic Press 1996
• Concin N. et al. Food Chem Toxicol 46 (2008) 544