BACKGROUND Methylmalonic acid (MMA), a sensitive biomarker of functional vitamin B12 deficiency, is commonly determined by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods using manual extraction and derivatization of MMA to reduce polarity prior to separation. METHODS In the present study we introduce a semi-automated extractio...

An air–assisted liquid–liquid microextraction method for the extraction and preconcentration of trace amounts of some synthetic phenolic antioxidants in biological fluids followed by their determination by gas chromatography–flame ionization detection has been reported. In this method the target analytes are extracted into a few microliters of carbon tetrachloride (extraction solvent) from an a...

Background and Objectives: The addition of plasticizers (mainly phthalates and adipates) makes plastic flexible and popular for packaging, storing and preserving food, water, and so on. The most widely used plasticizer in food contact applications is di-ethylhexyl phthalate (DEHP) though being suspected to have carcinogenic and estrogenic properties. The aim of this study is application of magn...

Comprehensive two-dimensional gas chromatography can be viewed as a traditional gas chromatography with a sophisticated "elution-resolved" flame ionization detector (GC/FID) or a detector with separation capability. The concept of multidimensional chromatography can be extended to other detectors that also have separation capability, such as ultraviolet, infrared, and mass spectrometer. Mass sp...

Accurate analysis of the main chemical components oil-bearing sludge is an important prerequisite for effective soil remediation and resource reuse. However, precise extract difficult to achieve because mutual interference saturates, aromatics, resins, collectively called SAR, asphaltene that are introduced during chloroform extraction. In this study, SAR was efficiently extracted using n-hepta...

Subcritical water extraction (SWE) of essential oil from Matricaria Chamomilla L.  (M. Chamomilla L.) was performed and compared with conventional method including hydro distillation. The percentage of main extracted components of different temperatures (100, 125, 150 and 175 oc) and water flow rates (1, 2 and 4 ml/min) were investigated at 20 bar pressure and 0.50 mm mean particle size in SWE....

An efficient and quantitative two phase freezing (TPF) method coupled with high performance liquid chromatography and UV-Vis detector was developed for the extraction, clean up and determination of clomiphene citrate (CLC) in plasma samples. The separation of two miscible solvents by TPF method permits that the CLC was efficiently removed from proteins and transferred into the relative aprotic ...

An efficient and quantitative two phase freezing (TPF) method coupled with high performance liquid chromatography and UV-Vis detector was developed for the extraction, clean up and determination of clomiphene citrate (CLC) in plasma samples. The separation of two miscible solvents by TPF method permits that the CLC was efficiently removed from proteins and transferred into the relative aprotic ...

Separation methods are being applied more extensively than ever before, particularly in trace analysis. Some of the more interesting procedures which have recently been proposed in solvent extraction and ion-exchange chromatography are reviewed, together with other new procedures for separation based on classical techniques. The possibilities of gas chromatographic separation of metal chelates ...