In Chapter 5, we discussed the basic NMR techniques and some of their applications to the analysis of petroleum fractions. Detailed band assignments were presented in Tables 5.5 and 5.6 of Chapter 5 and the overlap between many neighboring bands was evident. Spectral editing and http://www.w3.org/1998/Math/MathML"> 2 D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429081286/a0512751-e42a-435a-947a-195d2fd0474b/content/eq1831.tif" xmlns:xlink="http://www.w3.org/1999/xlink"/> techniques, developed during the last 15 years, have made it possible to resolve many of these bands which in regular http://www.w3.org/1998/Math/MathML">   13 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429081286/a0512751-e42a-435a-947a-195d2fd0474b/content/eq1832.tif" xmlns:xlink="http://www.w3.org/1999/xlink"/> -NMR spectra overlap. In Section II of this chapter we sketch the basic principles of these techniques. Very few applications of the advanced techniques to petroleum fractions have been published. Therefore, to show the potential as well as the limitations, we deviate here from our restriction to deal only with heavy petroleum fractions in this book and discuss some applications of these techniques to coal liquid fractions.