Establishment of analytical method on Shimadzu Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) for toxic elements in fruits

Importance of the Topic

Fruits are key in human nutrition but may accumulate toxic elements such as lead cadmium and mercury. Ensuring their safety requires sensitive reliable analytical methods for trace quantitation of these contaminants to protect consumer health

Objectives and Study Overview

This study aims to establish a robust inductively coupled plasma mass spectrometry method for simultaneous determination of Pb Cd As Hg Sn Zn and other elements in fruit matrices following regulatory limits set by FSSAI and EU standards

Methodology and Instrumentation

Sample Preparation Protocol

• Weighed about 500 mg of homogenized fruit sample into microwave vessels
• Added 2 mL high purity nitric acid and 2 mL ultrapure water for predigestion
• Applied a two step microwave digestion program reaching 120 and 180 degrees C with respective hold times of 5 and 20 minutes
• After cooling samples were diluted to 50 mL with ultrapure water and pre spiked for recovery studies at LOQ and ten times LOQ levels

Instrumentation Settings

• Shimadzu ICPMS 2030 with AS 10 autosampler and quartz mini torch
• Plasma RF power 1.2 kW sampling depth 5 mm
• Gas flows 10 L per min plasma gas 1.1 L per min auxiliary gas and 0.7 L per min carrier gas
• Helium collision gas at 6 mL per min for interference reduction

Calibration and Quality Control

• Intermediate stock standards at 1000 mg per L prepared for each element
• Linearity standards covering 10 to 250 percent of MRLs achieved with correlation coefficients above 0.999
• Continuous calibration verification at LOQ standards run periodically to monitor drift

Main Results and Discussion

Calibration curves exhibited excellent linearity for all target elements with r of at least 0.999. Spike recoveries ranged from 80 to 120 percent indicating accurate quantitation. Repeatability across four prep replicates yielded RSD below 8 percent. CCV recoveries were within 90 to 110 percent confirming system stability. Analyzed apple and pear samples showed element levels below the method LOQs demonstrating compliance with safety limits

Benefits and Practical Applications

The developed method offers several advantages for laboratories engaged in quality assurance and regulatory testing

• Rapid sample digestion and simple preparation workflow
• High sensitivity and multi element capability using ICP MS
• Robust performance across diverse fruit matrices
• Cost effective operation with minimal sample handling

Future Trends and Possibilities

Advancements may include automation of sample preparation enhanced collision cell technologies for better interference removal and coupling with separation techniques for complex matrices. High throughput screening and integration with data analytics pipelines will further improve operational efficiency and decision making in food safety monitoring

Conclusion

A straightforward ICP MS method was established delivering reliable determination of toxic elements in fruit samples. The approach meets international regulatory requirements and demonstrates strong accuracy precision and robustness suitable for routine food safety analysis

Reference

• Food Safety and Standards Contaminants Toxins and Residues Regulations 2011
• Food Safety and Standards Contaminants Toxins and Residues Regulations 2006
• Commission Regulation EU No 836 2011