Elemental analysis of heavy crude oil is important for a variety of reasons including region of origin, maturity, migration, type, and identification of potential challenges that could arise during the refining process. There are numerous challenges with analysis of heavy crude oil with most being centered on the sample prep process due to the complexity of the sample matric.
Microwave digestion has been used to overcome some of these challenges, however, traditional rotor based systems still face problems with limits of quantification due to sample size limitations, high residual organic contact (ROC), and high residual acidity.
The new paper follow site "Rare earth element determination in heavy crude oil by USN-ICP-MS after digestion using a microwave-assisted single reaction chamber", Druzian et al, J. Anal. At. Spectrom., 2016, 31, 1185, compares the digestion quality and maximum crude oil sample size of two microwave digestion systems Milestone’s Ultrawave (UW) and Anton Paar’s Multiwave 3000.
In this work a method for rare earth element (REE) determination by inductively coupled plasma mass spectrometry (ICP-MS) was proposed after heavy crude oil digestion by microwave-assisted wet digestion using our UltraWAVE.
Straight to the conclusions: to the best of the authors' knowledge, this is the first method able to digest 1 g of crude oil using wet digestion in closed vessels. This fact allowed the determination of those elements present at very low concentration in crude oil.
Digestion efficiency using the UltraWAVE was higher, providing low residual carbon and acidity in digests, which are important parameters to avoid interferences during the determination of REE by ICP-MS. The UltraWAVE combined good performance, safety and relatively high sample throughput since the digestion of up to 5 samples could be performed simultaneously in 40 minutes.
Finally, LOQs (limit of quantitation) were lower than those obtained using the Anton Paar Multiwave, as well as residual acidity.
Please read the complete article from here: http://pubs.rsc.org/en/content/articlelanding/2016/ja/c6ja00050a#!divAbstract