Does anyone here would like to share with me the best method for SARA analysis.I would like to Separate Saturate,Aromatic Resin and Asphaltene form crude oils sample.
I am preferred to used open column chromatography-gravimetry.
The ASTM D2007 is an "old" standard but it can represent a good start (after a prior topping and the asphaltene fraction removal). However, do not hesitate to adapt the sample preparation and/or the chromatographic conditions to your need because... there are as many SARA defintions as there are labs !
SARA analysis is used for many crude oil components. Asphaltenes can be pentane or heptane insolubles. Resins may be classified as a solubility fraction, such as heptane soluble, pentane insoluble, heptane soluble, and acetone or ethyl acetate insoluble, or as the polar fraction eluted from a polar adsorbent with a polar solvent, such as pyridine, toluene, or methanol.
When a SARA test sample is a heavy oil with minimal light ends, it is worth considering Iatroscan TLC-FID for which there is a standard method (IP-469). IP-469 determines all four compound classes by adsorption chromatography, so the asphaltenes content may differ numerically to that determined by IP-143. Typically, Iatroscan asphaltenes are about 80% of the IP-143 asphaltenes.
Measuring Asphaltenes by IP-143 and then determine SAR by IP-469 is possible. IP-469 does not involve a gravimetric finish, and light ends are still lost during the analysis, so this method works best with >300 degC distillates or residues.
SARA analysis alternatives including IP-143, followed by preparative HPLC (IP-368), or Clay-Gel (ASTM D-2007), which may be appropriate. SARA is also described as asphaltene, wax, and hydrate deposition analysis.
I would like to try open column chromatography method . But the problem is I does not get the exact amount of solvent that need to use for maltene separation. Anyone can help me.Thank you
based on our experiences, for more than 100 oil samples, HPLC results are more appropriate than the others ( gravity-driven chromatographic separation, thin layer chromatography (TLC)). For further info following article may be proposed: Evaluating Crude Oils by SARA Analysis, SPE 75228