2D-LC Solutions for Petrochemical Applications

The use of chromatography in all of its forms is a powerful and widely recognized practice in petrochemical research. Due to the continuous optimization of instrumentation and columns, substantial progress in terms of separation efficiency and selectivity, speed of analysis, and sensitivity has been made over the last decades. Many petrochemical products and derivatives thereof are generally complex due to presence of a large number of compounds with varying physicochemical properties. Moreover, these can be present in a wide dynamic concentration range. Obtaining a detailed insight into the composition of such samples still represents an analytical challenge, demanding for the highest separation power. 

Two-dimensional liquid chromatography (2D-LC) is a very powerful approach to increase peak capacity (separation power) as long as high orthogonality is established between the two dimensions and the separation obtained in the first dimension is maintained upon transfer to the second dimension. In comprehensive 2D-LC (LCxLC) the first dimension effluent is completely and continuously sampled in small fractions and transferred to the second dimension for ultrafast analysis (analysis time in the second dimension is typically below 30 s). This technique is useful for detailed profiling of complex mixtures. Heart-cutting (LC-LC) and multiple heart-cutting (mLC-LC) 2D-LC can be used to focus on well-defined peaks or regions in the first dimension chromatogram to gain better insight in the actual composition and potential impurities that may be undetected in one-dimensional LC analyses. 

Results obtained with the different 2D-LC modes will be presented using state-of-the-art instrumentation and software. Qualitative and quantitative aspects will be illustrated using some key applications.