QuEChERS sample preparation was optimized using solvent extraction with acetonitrile and dispersive-solid phase extraction with primary and secondary amine sorbents, and validated for high-performance liquid chromatographic determination of nine steroids commonly used to adulterate herbal medicines: such as triamcinolone, prednisolone, hydrocortisone, methylprednisolone, betamethasone, dexameth...

Urinary 1-hydroxypyrene is frequently used as a major metabolite and biological indicator of the overall exposure to polycyclic aromatic hydrocarbons. In this study, solid phase extraction was appropriately conditioned with regard to sample pH, sample concentration, loading flow rate, elution solvent, washing solvent, sample volume and sorbent mass. Octadecyl silica cartridge (C<su...

a fast and simple modified quechers (quick, easy, cheap, rugged and safe) extraction method based on spiked calibration curves and direct sample introduction was developed for determination of benzo[a]pyrene (bap) in bread by gas chromatography-mass spectrometry single quadrupole selected ion monitoring (gc/ms-sq-sim). sample preparation includes extraction of bap into acetone followed by clean...

This technical note explains the disadvantages of manual solid phase extraction (SPE) techniques and the benefits to be gained with automatic systems. The note reports on a number of general and highly specific applications using the Sample Preparation Unit OSP-2A.

Spectrometric techniques for the analysis of trace cadmium have developed rapidly due to the increasing need for accurate measurements at extremely low levels of this element in diverse matrices. This review covers separation and preconcentration procedures, such as electrochemical deposition, precipitation, coprecipitation, solid phase extraction, liquid-liquid extraction (LLE) and cloud point...

urinary 1-hydroxypyrene is frequently used as a major metabolite and biological indicator of the overall exposure to polycyclic aromatic hydrocarbons. in this study, solid phase extraction was appropriately conditioned with regard to sample ph, sample concentration, loading flow rate, elution solvent, washing solvent, sample volume and sorbent mass. octadecyl silica cartridge (c18) was used as ...

dispersive liquid–liquid micro–extraction (dllme) technique was successfully used as a sample preparation method for the determination of clonazepam in pharmaceutical preparations and water samples. in this method, a suitable mixture of methanol (disperser solvent) and chloroform (extraction solvent) was injected rapidly into a conical test tube that contained an aqueous solution of clonazepam....