PEFTEC 2019 - Abstract

Abstract Title: The no fuss ICP-MS approach for the analysis of trace level metals in petrochemical feedstocks
Abstract Type: Oral
Session Choice: Analytical Techniques: Elemental Analysis and Speciation
Presenter Name: Dr Christian Wold
Co-authors:Mr Barry van Hooff
Dr Christoph Roosen
Company/Organisation: SABIC
Country: Netherlands

Abstract Information :

The presence of inorganic species in feedstocks is of particular importance with regard for example to the continuous operation of steam crackers and in particular, the avoidance of inorganic related corrosion, product contamination or fouling. Elemental analysis techniques1 such as AAS, ICP-OES have commonly been applied to the analysis of petrochemical feedstocks used for cracking purposes. Due to increasing demands for lower limits of detection the use of such techniques in general requires very sensitive methods of sample concentration during preparation, for example pre extraction of large quantities of sample into smaller volumes of solvent through refluxing.

Such sample concentration methods are both time consuming and prone to contamination resulting in erroneous results. We present an ICP-MS method based on microwave digestion of neat naphtha samples, an approach that minimizes sample-handling complexity, allows ease of calibration and takes advantage of the very low detection limits available with ICP-MS. The importance of sample pretreatment through ultra-sonication to prevent loss of information in metals due to sedimentation is discussed as well as the importance of taking representative samples in the field.

The method is compared by a spiking study with that of a more traditional approach using soxhlet reflux and optical ICP equipment. The resulting method provides clear advantages in terms of productivity repeatability of results and achieves similar detection limits for most elements of interest.