many modern analytical methods deal with the trace-level determination of compounds of interest in highly complex environmental samples by means of chromatographic techniques. the introduction of a “clean” sample into an analytical instrument can make analyses easier and prolongs the equipment life. the use of solid-phase extraction (spe) has grown and is a fertile technique of sample preparati...

Dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography-massspectroscopy (GC-MS) was used to analyses of components of floral-water of Rosmarinusofficinalis . Some effective parameters such as volume of extraction, disperser solvents andsalt effect were studied by a full factorial design for obtain the optimum condition. The maincompounds of the floral-water of Rosmarinu...

This paper describes a new separation process of liquid-liquid extraction. It consists of first mixing the system to be extracted with a primary solvent, which is soluble with the native solvent, and subsequently adding a modifier, which is insoluble with either the native or the primary solvent. This process is similar to the phase transition extraction, which was described in a previous paper...

Comparative Study of Liquid-Liquid Extraction and Solid-Phase Extraction Methods for the Separation of Sufentanil from Plasma before Gas Chromatographic– Mass Spectrometric Analysis, Christelle Dufresne, Patrick Favetta, Chantal Paradis, and Roselyne Boulieu ( Université Claude Bernard Lyon 1 (U.C.B.L.), Institut des Sciences Pharmaceutiques et Biologiques (I.S.P.B.), Département de Pharmacie C...

Pressurized liquid extraction (PLE) and pressurized hot water extraction (PHWE) using a laboratory-made system are applied for the extraction of thermally labile components such as tanshinone I and IIA in Salvia miltiorrhiza. PLE and PHWE are carried out dynamically at a flow of 1 mL/min, temperature between 95-140 degrees C, applied pressure of 10-20 bars, and extraction times of 20 and 40 min...

Three extraction methods were compared for their efficiency to analyze sitagliptin and simvastatin in rat plasma by LC-MS/MS, including (1) liquid-liquid extraction (LLE), (2) solid phase extraction (SPE) and (3) supported liquid extraction (SLE). Comparison of recoveries of analytes with different extraction methods revealed that SLE was the best extraction method. The detection was facilitate...

The use of liquid-liquid extraction for the separation of zirconium from hafnium was demonstrated. Hafnium spectrographically free of zirconium was prepared in quantity on a continuous basis. High purity fractions of zirconium were also prepared.

If a matrix effect is detected during the validation stage of an analytical method, the standard addition methodology must be applied. To reach a good estimation of the uncertainty associated with the determination, an adequate identification and evaluation of each uncertainty source should be done. As an example to illustrate how to calculate the uncertainty in this case, the simultaneous dete...