in recent years, sustainable development has been accounted as one of the most important policy goals at the global level. many empirical studies have been carried out to determine the relationship between economic growth and environmental quality. the model so-called environmental kuznets curve (ekc) was in most of empirical studies. the aim of this study is to estimate a modified ekc (mekc) i...

The determination of the thyreostatics 2-thiouracil, its derivatives (4-methyl-2-thiouracil, 4-propyl-2-thiouracil and 4-phenyl-2-thiouracil) and methimazole in manufactured dried animal feed by micellar electrokinetic chromatography (MEKC) is described. A 99 +/- 5% extraction yield at the 20 micrograms g-1 level (n = 8) was achieved by shaking the milled fodder with methanol-1 M NaOH (80 + 20)...

Micellar electrokinetic chromatography (MEKC) was examined for the separation and determination of Mo(VI), Cr(VI), Ni(II), Pd(II), and Co(III) as diethyl dithiocarbamate (DDTC) chelates. The separation was achieved from fused silica capillary (52 cm × 75 μm id) with effective length 40 cm, background electrolyte (BGE) borate buffer pH 9.1 (25 mM), CTAB 30% (100 mM), and 1% butanol in methanol (...

The analysis and characterization of lipids andwaxes is of great importance in the food industry, pharmaceutical and cosmetic industry, in surfactant and detergent technology and in natural product research. Lipid analysts have always been on the forefront of developments in separation sciences and new techniques in chromatography have often been developed for the separation of lipids. The Rrst...

BACKGROUND Polygoni Multiflori Radix, He-Shou-Wu in Chinese, is a widely used traditional Chinese medicine. Clinically, water decoction is the major application form of He-Shou-Wu. Therefore, simultaneous determination of bioactive compounds in water extract is very important for its quality control. RESULTS A pressurized liquid extraction and short-end injection micellar electrokinetic chrom...

A rapid and sensitive method for the multiresidue analysis of six commonly used carbamate pesticides in apples was developed by using dispersive liquid–liquid microextraction (DLLME) coupled with sweeping micellar electrokinetic chromatography (MEKC). Parameters that affect the extraction and sweeping efficiency, such as the kind and volume of the extraction and disperser solvent, extraction ti...

A separation method was developed in order to quantify free amino acids in passion fruit juices using CE-UV. A selective derivatization reaction with FMOC followed by MEKC analysis was chosen due to the highly interconnected mobilities of the analytes, enabling the separation of 22 amino acids by lipophilicity differences, as will be further discussed. To achieve such results, the method was op...

Poly(sodium undecenoyl-L-leucinate) (poly-L-SUL) was fractionated by the use of different molecular weight cutoff (MWCO) filters to narrow the polydispersity of the macromolecular sizes of the polymeric surfactant. The resulting polymeric surfactant fractions were characterized by the use of three techniques: (1) pulsed field gradient nuclear magnetic resonance (PFG-NMR) was used to determine t...

Since the turn of the twentieth century, it has been recognized that many drugs, agrochemicals, food additives and fragrances are chiral compounds and their chirality may considerably affect their bioactive behavior [1, 2]. The demand has been increasing for new analytical methods with high selectivity and efficiency. Chiral separation has become an attractive and important field in the separat...