Aromatic carbon mole ratios[C(ar)%] in model oil samples, which consisted of 11 saturated/unsaturated compounds with known contents, were determined by quantitative carbon nuclear magnetic resonance spectroscopy (13C qNMR) with the design for six Sigma (DFSS) methodology. An empirical model was established between C(ar)% and sample parameters, including sample concentration (Conc.), concentration of relaxation reagent Cr(acac)3 and relaxation delay (D1). Based on the model, the optimal condition was determined to be at sample concentration 180 mg/mL, concentration of Cr(acac)3 12 mg/mL and D1 10.5 s. Eight verification experiments were performed under the optimal condition, and the results showed fairly good repeatability (RSD=0.61%) and accuracy (99.0%~100.6%). The work also gave some supplementary suggestions on parameter settings for the current GB method/ASTM method.
MA Lin-ge
,
LONG Yin-hua
. Determination of Aromatic Carbon Mole Ratio in Oil Samples by Quantitative 13C NMR Spectroscopy with DFSS Methodology[J]. Chinese Journal of Magnetic Resonance, 2017
, 34(1)
: 8
-15
.
DOI: 10.11938/cjmr20170102
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