Measurement of serum triglycerides by thin-layer chromatography and infrared spectrophotometry

A direct and nondestructive method for the quantitative determination of serum or plasma triglycerides has been developed. The lipid extract of 1 ml of serum is chromatographed on I-mm wet-thickness silicic acid layers prepared from a water–acetone slurry. Following elution, triglycerides are quantified by infrared spectrophotometry. For both synthetic and naturally occurring triglycerides, a nonlinear relationship of absorptivity as a function of concentration has been characterized. Triglyceride fatty acid chain length and degree of unsaturation have no significant effect on analytical results under the conditions described. Precision of the method is 2% and accuracy 4%. Recoveries average 96%. The method is sensitive to serum concentrations as low as 20 mg/100 ml. Triglyceride levels of a group of 51 healthy males, age 40 to 59, were determined. The mean postabsorptive triglyceride value was 93 mg/100 ml, with a standard deviation of 43 mg/100 ml. The system permits preservation of the triglyceride molecule intact for subsequent procedures such as characterization of the fatty acid moiety and substitution pattern.