Rapid Determination of Phosphorus in Steel by Electrolytic Gas Introduction-ICP-AES Method

Solid steel sample dissolution with electrolysis-inductively coupled plasma atomic emission spectrometry (ICP-AES) is applicable to multi-elemental analysis of steel by analyzing the elements in the electrolyte. The disk-shaped steel sample is electrolyzed through an electrolysis cell and the electrolyte is introduced into the ICP continuously. However, the sensitivity of phosphorous was not enough practically.We examined to improve the sensitivity with sample heating and electrolytic gas introduction system. At room temperature, phosphorus exists as PO43- ion in the electrolyte, and sensitivity was not enough due to the low efficiency in sample introduction efficiency to the plasma via nebulizer. However when the sample was heated, gaseous PH3 improved introduction efficiency therefore sensitivity was improved remarkably. When the steel samples taken from steel making process, heated at 80°C, were analyzed with the technique in which generated gas in the electrolysis was introduced to the plasma, the analytical results were in a good agreement with these of the result of the phosphovanadomolybdate spectrophotometric method.