Proton (s)

Functional group

Chemical shift, δ (ppm)

Oil

Biodiesel

CH₃-C

Terminal methyl group

0.80 - 1.01

0.8 - 1.0

-(CH_2)n-

Backbone CH₂

1.20 - 1.41

1.22 - 1.42

-CH₂CH₂-COOH

β-methylene proton

1.53 - 1.70

1.55 - 1.69

=CH-CH₂-

α-methylene group to one double bond

1.94 - 2.11

1.93 - 2.10

CH₂COOR

α-methylene group to ester

2.31

2.31

=CH-CH₂-CH=

α-methylene group to two double bonds

2.76

2.77

-COOCH₃

Methyl group of ester

-

3.67

-CH₂OCOR

Methylene group (C₁ and C₃) of glyceride

4.09 - 4.34

-

-CHOCOR

Methinine proton at C₂ of glyceride

5.25

-

-CH=CH-

Olefeinic protons

5.28 - 5.43

5.27 - 5.41