Overview
EN ISO 11212-2:1997 is an international standard developed by CEN that specifies a precise analytical method for determining the mercury content in starch and its derived products. Mercury, a toxic heavy metal, can contaminate starch during processing or from the environment, posing health risks. This standard outlines the use of atomic absorption spectrometry with cold-vapour generation to accurately quantify mercury levels in starch materials. This method supports quality control, regulatory compliance, and safety assurance in starch-related industries.
Key Topics
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Scope and Purpose
Defines a standardized procedure to measure mercury content (expressed in micrograms per kilogram) in starch, derivatives, and by-products using atomic absorption spectrometry.
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Analytical Principle
Involves wet digestion of samples, reduction of mercury ions to metallic mercury through sodium borohydride or tin(II) chloride in hydrochloric acid, and detection of monoatomic mercury vapour absorbance at 253.7 nm wavelength.
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Sample Preparation and Digestion
Homogenization of starch samples followed by reflux distillation with nitric acid and hydrogen peroxide for organic matrix breakdown.
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Reagents and Calibration
Use of purified reagents (nitric acid, hydrogen peroxide, sodium borohydride, tin(II) chloride, hydrochloric acid) and preparation of mercury standard solutions for calibration curves.
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Apparatus Specifications
Requires a digestion apparatus with Soxhlet extraction tube and cooling system, atomic absorption spectrometer with mercury discharge lamp, and a cold mercury vapour generator equipped with an automatic sampling device.
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Measurement and Calculation
Absorbance measurements are compared against a calibration curve to calculate mercury concentration. The standard includes formulas and guidance to express results accurately.
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Precision and Repeatability
Interlaboratory studies confirm the method’s reliability with defined repeatability and reproducibility limits, ensuring consistent mercury detection across different labs and testing conditions.
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Safety Considerations
Emphasizes the toxicity and volatility of mercury, recommending precautions such as verification of apparatus tightness and controlled digestion temperature to prevent mercury vapour loss.
Applications
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Food Safety Testing
Ensures that starch ingredients used in food manufacturing comply with mercury contamination limits, protecting consumer health.
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Quality Control in Starch Production
Enables manufacturers to monitor and minimize heavy metal impurities, maintaining product quality and meeting regulatory standards.
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Environmental Monitoring
Assists laboratories in detecting mercury contamination in starch derived from agricultural sources exposed to polluted environments.
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Regulatory Compliance
Provides a validated standard method for reporting mercury content in starch products, aligning with food safety and chemical contaminant regulations.
Related Standards
EN ISO 11212 is a multi-part standard series addressing heavy metals in starch products, including:
- EN ISO 11212-1: Determination of arsenic content by atomic absorption spectrometry.
- EN ISO 11212-3: Determination of lead content by atomic absorption spectrometry with electrothermal atomization.
- EN ISO 11212-4: Determination of cadmium content by atomic absorption spectrometry with electrothermal atomization.
These related standards collectively support comprehensive heavy metal analysis to ensure starch product safety and compliance.
Keywords: EN ISO 11212-2, mercury determination, starch heavy metals, atomic absorption spectrometry, cold-vapour generation, mercury content analysis, starch quality control, heavy metal testing, food safety standards, mercury spectrometry method.