For the purpose of establishing the quantometric analysis of As in several kinds of low alloy steel as routine works, a study was made about the interference lines and the segregation in the specimen. The results obtained are as follows:
When As 2349.84 A line is used for the quantometric determination of As with low voltage arc excitation the interference due to near-by lines is remarkable in the case of low alloy steel, especially of a high Mo concentration above 0.10%.A correction curve which was made to eliminate the interference effect is widely applicable to many kinds of steel, and the variation coefficients are found to be 7-8% in steels of above 0.025% in the concentration of As.
However, in a heat-treated sample, it was found that As-concentration is thick at the sample surface (boundary between metal and scale).

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A study was made on sampling of cast iron for accurate analysis by the use of the Quantovac.A sample cast in a“mushroom”type mould was proved to have the most uniform structure and to give the best analytical result.
Sampling position in the ladle is found to significantly affect the Quantovac values of Mg and S, and also the result of chemical analysis of C.
In the case of large concentration of C, the Quantovac value of C exceeds its chemical value with increase of precipitation of kish graphite which is inevitable in super eutectic cast iron.To overcome this problem, we studied two methods, one of which was to add a chill-promoting element to the molten metal, and the other, to use correction curves which were statistically determined to coincide the Quantovac value with the chemical value.While the former is applicable only to some plain case iron, the latter can be applied for any kind of cast iron with a carbon content up to 4.20%.

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By the iron oxide powder-d.c.arc spectrographic method, the concentration of lanthanum from. 0.005 to 1 per cent and cerium from 0.008 to 0.6 per cent in iron and steel are determined with a standard deviation less than 0.02 per cent.By using these samples as the standard in the ingot. spectrographic method, the excitation was performed by a high voltage a.c.arc or a spark depending on the concerned elements.The high voltage a.c.arc method is better than the spark method because of the wide range of detection and the linearity and the repeatability of the calibration curves for these elements.By using the same standard sample, the concentration of lanthanum from 0.005 to 0.73 per cent and cerium from 0.008 to 0.35 per cent are determined with a standard deviation less than 0.008 per cent by the fluorescent x-ray method with LaLa and CeLα line.And by the copper spark spectrographic method, the concentration of lanthanum, cerium, praseodymium, neodymium, . samarium, europium, gadolinium and terbium of 1 to 5γ/ml in iron and steel are determined by the extraction method with methyl iso-butyl ketone.

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