Current Analytical Chemistry - Volume 10, Issue 1, 2014

This review provides an updated discussion on the recent developments and applications of supercritical fluid technology in analytical chemistry. Supercritical mediums are usually used for extraction and separation of various analytes in analytical science. Although, this technology is used for chromatographic aims in the analysis of various samples the main application domain of supercritical fluids is in extraction process. SFE Read More

Due to the potential for health benefits, the importance of carotenoids is growing. Since this group of compounds is used in medical as well as food and cosmetic applications, a review of the current sources of carotenoids is undertaken. A literature survey is presented related to the methods currently used for the extraction of carotenoids from plants: low-pressure solvent extraction by different techniques and supercritical flu Read More

Extraction with supercritical fluids arises in the last three decades as a promising alternative to conventional analytical methods for lipid extraction, and currently has consolidated its application in extraction processes of raw materials of animal and plant origin. Its advantages over conventional techniques are many and well known, but this technology stands out mainly by environmental factors and quality of products. This articl Read More

A process based on the use of a semi-continuous countercurrent supercritical fluid extraction (CC-SFE) has been optimized to concentrate minor components, with functional properties, from olive oil. The optimization of the main variables involved in the supercritical extraction process (extraction pressure, temperature and sample flow rate) was performed using a surface response methodology (RSM). A central compo Read More

Hyphenated SPE/SFE method was developed for the extraction of phenolic compounds from plant matrices (6 algae species). 20 ml of liquid solvent was injected to the SPE cartridge and extracted at following conditions: 40 MPa, 80°C, restrictor 10.5 cm x 50 μm i.d. for 60 min into 20 ml of MeOH as a trapping solvent. Two different methods were developed for different SPE sorbents (OASIS MCX 3cc, Waters and ADVANTA Spe-ed, Read More

This paper presents a review of the literature covering separations of enantiomers achieved with supercritical fluids. Supercritical fluid chromatography (SFC) is the main technique represented but chiral extraction (chiral SFE) and simulated moving bed (SMB) are also present. First of all, a historical view of the technique is presented. Then stationary phases, mobile phases and operating conditions are discussed, wit Read More

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that must be diagnosed early to increase drug therapy efficacy. No early definitive diagnostic tool, however, is currently available, thus prompting for the identification of biomarkers of the disease. Isoprostanes (iPs) are prostaglandin-related free radical oxidation products of polyunsaturated fatty acids (PUFA) that are produced under oxidative stress con Read More

One of the most exciting recent developments in infrared spectroscopy has been the coupling of the spectrometer to an infrared microscope. The combination of the new infrared spectrometer and a microscope was a natural thought of scientists in these fields. This development has been so rewarding and so useful in solving today's chemical problems that infrared microspectroscopy has quickly become a significant subclassi Read More

A simple and fast on-line chromatographic procedure has been developed for separation of 134Cs, 135Cs, 137Cs and 87Sr ions from interfering isotopes of 134Ba, 135Ba, 137Ba and 87Rb. This analytical method offers the possibility to measure the chromatograms of Rb, Cs, Sr and Ba isotopes using ICP-MS technique in isocratic conditions in one run. For the separation, the oxalic acid neutralized with ammonia could be Read More

Flucloxacillin (FLU) is a semi-synthetic penicillin active against Gram-positive bacteria such as streptococci and penicilinase-producing staphylococci, including methicillin-susceptible S. aureus. A simple, rapid and reproducible stability-indicating micellar electrokinetic chromatography (MEKC) method was developed and validated for analysis of flucloxacillin sodium in capsules, using nimesulide as internal standard. The MEKC m Read More

A derivative UV spectrophotometric method for determination of paliperidone in OROS® tablets was validated and compared to a previously validated HPLC. The parameters specificity, linearity, precision, accuracy, LOD and LOQ were studied according to official guidelines. The first-order derivative spectra were obtained at N = 5,Δλ= 1.0 nm, and determinations were made at 288 nm. The drug was extracted from osmoti Read More

This work proposes an alternative method for determination of sodium, potassium, calcium, and magnesium in biodiesel by flame atomic absorption spectrometry (FAAS), using dissolution in ethanol for sample preparation. The ethanolic medium enabled the use of aqueous standards, and adjustment of the viscosity of the solutions was achieved using samples of washed biodiesel, free of the analytes. The analytical cur Read More

The purpose of this study is to investigate the retention behavior of weakly ionizable basic compounds in ionsuppression reversed-phase liquid chromatography (IS-RPLC) using ammonia or triethylamine as ion-suppressor in a binary hydroorganic mobile phase. The apparent n-octanol-water partition coefficient (Papp) was proposed to adjust the noctanol- water partition coefficient (Po/w) of weakly basic compound. LogPapp w Read More