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A capillary electrophoresis method with ultraviolet (UV) detection was developed and optimized for the enantiomer separation of norepinephrine (NE), epinephrine (EP) and isoprenaline (IP) using dual cyclodextrins (CDs) of 2-hydroxypropyl-␤-CD (HP-␤-CD) and heptakis (2,6-di-o-methyl)-␤-CD (DM-␤-CD) as chiral selectors. Optimal separation was obtained using a running buffer of 50 mM phosphate containing 30 mM HP-␤-CD and 5 mM DM-␤-CD at pH 2.90 and a field strength of 20 kV in 45 cm × 75 m (40 cm effective length) uncoated capillary. The UV absorbance detection was set at 205 nm. A 0.1% (w/w) polyethylene glycol or 0.1% (v/v) acetonitrile was used to enhance the detection sensitivity. There was a wide and excellent linear calibration graph for each enantiomer in the range 1.0 × 10 −3 to 1.0 × 10 −6 M and the detection limit (S/N = 3) was found from 8.5 × 10 −7 to 9.5 × 10 −7 M. The method has been applied for the determination of isoprenaline in isoprenaline hydrochloride aerosol and to the analysis of serum samples. The recoveries of NE and EP in serum and IP in drug were ranged from 90 to 110%. The relative standard deviations of all the analyte peaks were less than 2.8% for migration time and less than 4.8% for peak area.

Microwave-assisted hydrodistillation (MAHD) is an advanced hydrodistillation (HD) technique, in which a microwave oven is used in the extraction process. MAHD and HD methods have been compared and evaluated for their effectiveness in the isolation of essential oils from fresh mango (Mangifera indica L.) flowers. MAHD offers important advantages over HD in terms of energy savings and extraction time (75 min against 4 h). The composition of the extracted essential oils was investigated by GC-FID and GC-MS. Results indicate that the use of microwave irradiation did not adversely influence the composition of the essential oils. MAHD was also found to be a green technology.

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A solid-phase microextraction probe was prepared on the surface of a stainless-steel wire through molecular sol-gel imprinting technology using chlorpyrifos as a template molecule, tetraethoxysilane as a sol-gel precursor, and acrylamide and β-cyclodextrin as functional monomers. The polymer was characterized by infrared spectrometry and scanning electron microscopy. Moreover, the selectivity and the parameters including the type and volume of the extraction solvents, ionic strength, pH, temperature, extraction time, stirring speed, and desorption time affecting extraction performance were evaluated. Under the optimum solid-phase microextraction and gas chromatography conditions, the linear ranges were 0.25-25.0 μg/L for chlorpyrifos, quinalphos, triazophos, pirimiphos-methyl, and chlorpyrifos-methyl with the correlation coefficient above 0.99. The detection limits (S/N = 3) were in the range of 0.02-0.07 μg/L and the RSDs were <7.3%. The developed method was successfully used to determine the multi-residues of chlorpyrifos, quinalphos, triazophos, pirimiphos-methyl, and chlorpyrifos-methyl in green peppers and cinnamon with satisfactory recoveries.

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Molecularly imprinted solid phase extraction for determination of aflatoxin M1 and B1 in foods and feeds.