Quantitative determination of fat emulsion using 1,6-diphenyl-1,3,5-hexatriene as fluorescence probe: application to the compounding of all-in-one parenteral nutrition admixtures.

Abstract The potential contamination of binary bags by traces of fat emulsion stemmed from ternary bags prepared just before, led us to determine traces of lipids into the line set of the automated compounder MM23®. Diphenylhexatriene (DPH) was chosen as fluorescence probe due to its strong fluorescence enhancement in a lipid environment. Optimization of experimental conditions (i.e. DPH amounts, pH of fat emulsion samples, ultrasounds use, light, temperature and contact duration) for fluorescence measurement and validation of analytical method were performed. This method was linear over 0.5–8.0 mg l −1 ( r =0.999) of fat emulsion. The intra-day and inter-day precisions were inferior to 2% for the 2.0 and 8.0 mg l −1 standards. Under optimized conditions, the detection limit and quantitation limit were 0.10 and 0.29 mg l −1 of lipids respectively. Compared to the colorimetric method using sodium dichromate, it is at least 100 times more sensitive. The proposed method permitted to rapidly measure fat emulsion traces in automated compounder line set for parenteral nutrition solutions and thus, to assess the risk of contamination of binary bags by lipids. At last, this method was shown to be conveniently applied to the analysis of fat emulsion in the final total parenteral nutrition bag.