Separation and quantification of components of edible fat utilizing open tubular columns in SFC. Sample introduction by direct injection and SFE coupled on-line to SFC

Automatic microgravimetric determination of fats in milk products by use of supercritical fluid extraction with on-line piezoelectric detection

An on-line supercritical fluid extraction-piezoelectric detection system was developed and applied to the quantitative gravimetric determination of total fat in food samples (skimmed milk and cocoa). The proposed assembly provides all the advantages of an on-line system as regards automation, in addition to acceptable sensitivity and precision. Its strength lies in the design of the interface between the supercritical fluid extractor and the piezoelectric detector. Samples of skimmed milk and cocoa are weighed in the extraction thimble, previously loaded with I g of diatomaceous earth. A temperature of 100 degrees C and a CO2 fluid density of 0.60 mg/ml are used for extraction. The linear calibration range thus achieved is 0.005-0.07% w/w total fat, and the relative standard deviation is +/-2.3% (n=11; P=0.05). The throughput is six samples h(-1) (for the overall process). The proposed method was used to determine the total fat in food samples (milk, cocoa), the results being competitive with those of the Soxhlet methods for the same purpose.

Routine analysis of hydrocarbons, PCB and PAH in marine sediments using supercritical CO2 extraction

Automated Supercritical Fluid Extraction (SFE), using CO2, was tested and optimised for routine analysis of hydrocarbons (THC), polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) in marine sediments. The aim of the exercise was to reduce the amount of solvents used and to reduce the manual handling time for each sample. The sediments contained elemental sulphur, which was removed during the extraction step using activated Cu. Similar recoveries and reproducibility where found for THC when conventional solvent extractions and SFE where compared. Modifying the CO2 with methanol was necessary to obtain extraction recoveries similar to conventional extraction methods for PCB and PAH.