LGC improving the accuracy of tin analysis in canned foods

A new reference material now available from LGC Promochem is set to improve the reliability and reproducibility of data on the levels of tin, cadmium and lead found in food. ERML-BC084a Tomato paste certified for tin, lead and cadmium was produced by LGC in response to the widespread problem of achieving accuracy of tin data amongst the analytical laboratories involved in the FAPAS® proficiency testing scheme.

Canned foods can be contaminated with certain metals during the preparation and packaging process. Additionally, manufacturers are permitted to add metals that function as additives. Tin chloride (E512) is often used in small quantities as an antioxidant and to aid colour retention in canned and bottled foods. However, excessive levels of tin in foodstuffs can cause gastric irritation, so a regulatory limit of 200 mg/kg of tin in canned food has been set by the European Union along with permitted levels for lead and cadmium.

In collaboration with LGC, the UK Central Science Laboratory (as part of their FAPAS® scheme), found an unexpected common bias in the measurement results amongst laboratories determining tin levels in food. LGC was asked to provide an independent reference value for the proficiency testing samples using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) with isotopic dilution (IDMS), which revealed a bias of over 20% in the consensus value. The LGC IDMS method has been verified as part of a high level international comparison.

The new matrix certified reference material ERML-BC084a Tomato paste certified for tin, lead and cadmium was produced for use in the validation of methods for the determination of tin, lead and cadmium in a fruit or vegetable based material. It may also be used for monitoring the ongoing performance of a method. Production of this reference material was supported under contract with the Department of Trade and Industry as part of the VAM (Valid Analytical Measurement) programme. LGC recently gained UKAS accreditation to ISO Guide 34 and ISO/IEC 17025 for the production of reference materials.

ERML-BC084a is now available from LGC Promochem in 50g units packaged in amber glass bottles with tamper evident closures, and finally provides analytical laboratories everywhere with a means of checking for bias in their results and establishing traceability for their data. For further information about ERML-BC084a Tomato paste certified for tin, lead and cadmium, please contact LGC Promochem.