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This standard specifies a method for analyzing the mass fractions of the impurities Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Si, Sn, Sr, Ti, V, W, Y, Zn, Zr in graphite powders, granules and lumps.

This method is applicable with restrictions to boron and silicon in terms of limited calibration options. The accuracy of determinations of boron and silicon in graphite carried out in accordance with this method depends on the respective graphite material (raw materials, production and morphology) and shall be validated by means of an independent method for each type of graphite.

Subject to the main influencing variables (element, wavelength, plasma conditions and sample weight), the method is applicable to mass fractions of the above-mentioned impurities ranging from about 0,001 mg/kg to about 10 000 mg/kg; this range can be limited depending on the element and wavelength.

NOTE As a rule, a linear working range of up to four orders of magnitude applies to optical emission spectrometry using inductively coupled plasma (ICP OES) and electrothermal vaporization (ETV). This range can be extended for individual elements by varying the sample weight or by selecting lines of different sensitivity.

This standard is also applicable to soot, coke and coal with a mass fraction of ash of up to 1 %. Subject to previous testing, the standard can be applied to other carbonaceous sample mixtures and residues after sample incineration.

Positive experience has also been gained with incinerated organic materials ([1], [23] and Annex D).