Rationale

Summary: ? Determination of the elements Al, B, Ca, Fe, Si, Ti and V in graphite by photometric methods Problems: In general, photometryis suitable for a sensitive and accurate determination of the elements Al, B, Ca, Fe, Si, Ti and V, but: It is an outdated method which, as far as I know, is nowadays only rarely used for the chemical analysis of graphite It is questionable if technical expertise for these photometric methods is still available in our subcommittee Simultaneous determination of the elements not possible Requires a high expenditure in terms of chemicals and labour time Limited to only 7 elements The standard would require some editorial and technical revision No precision data available. If the standard is submitted to ballot this would require an ILS Methods commonly used today: Wet-chemical methods: Ashingof the graphite sample according to ASTM C561 Dissolution of the ash by alkaline melt fusion or acid-pressure decomposition Measurement of the elements in the sample solution using atomic-or mass-spectrometric methods (e.g. ICP-OES, AAS, ICP-MS) Examples for standard test methods: ASTM D5600 Standard Test Method for Trace Metals in Petroleum Coke by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) ASTM C781 Standard Practice for Testing Graphite Materials for Gas-Cooled Nuclear Reactor Components, section A.5 (boron by calcination and ICP-OES) Note: Nowadays, the analysis of aqueous sample solutions by atomic-or mass-spectrometric methods can be considered as general knowledge of a laboratory. A standard in which these measurements are described in detail is therefore not really necessary. Only the sample preparation procedure is important. Direct methods: ETV-ICP-OES ?see ASTM D8186 GDMS