Current Analytical Chemistry - Volume 9, Issue 3, 2013

Lignin, the second most abundant terrestrial biopolymer, still continues to reveal fascinating complexity within its structural polymeric framework. In this regard, Pyrolysis gas chromatography mass spectrometry (Py-GC/MS) has emerged as a simple, quick and reliable analytical technique for lignin structural analysis. The literature on wide range of applications of Py-GC/MS for lignin analysis is surveyed and subsequent determi Read More

Stilbenes are naturally occurring plant polyphenols, which have received considerable attention due to their various biological activities, structural complexity and diversity. Rapid analysis and separation of stilbenes have been a challenge for phytochemists and analytical chemists. In recent years, major advances have been achieved by application of HPLC/MS, MS/MS and CCC. Also, many novel methods have been successfu Read More

Phenolics, which occur widely in plants, encompass a wide range of structural classes and impart biological function to plants. They have been investigated in plants as anti-stress compounds, biosynthesized in response to abiotic and biotic stress such as pathogen attack, heavy metal, UV irradiation, and chemical stressors. In many cases, particularly for plant-metabolites interactions, analytical methods of stress driven ph Read More

Marine floras contain more than 4000 polyphenolic compounds, including phlorotannins, flavonoids, anthocyanidins, lignin, tannins, catechin, epicatechin, epigallocatechin and hydroxylated polybrominated diphenyl ethers. Massive investigations have been carried out on marine polyphenols, and a great number of methods have been developed for the analyses of marine polyphenols, which possess an array of bi Read More

Tea is rich in polyphenol compounds, which possess antioxidant and anticarcinogenic activity, and are becoming increasingly popular because of their potential role in contributing to human health. Responding to the increasing interest in the health promoting properties of tea as well as a significant rise in scientific investigation, we have given an overview of the current analytical methods for determination of polyphenol c Read More

Mentha and Thymus are important genera of the Lamiaceae family widely distributed in the entire World and commonly used in traditional medicine. Indeed, many species of the two genera have been credited with a large list of health-benefit effects, including antioxidant, anti-inflammatory, antimicrobial, analgesic, neuroprotective and anticarcinogenic. In turn, these properties have been associated to the poly Read More

Anthocyanins are an important group of polyphenols that have health promoting properties. Analytical techniques for profiling anthocyanins have been widely reported in the last decade for in vitro and in vivo studies. A number of important technological advances in high-performance liquid chromatography (HPLC) and the introduction of the ultra high-performance liquid chromatography (UHPLC) have achieved significant ga Read More

Phenolics are related to a number of pharmacological effects and form an important category among secondary plant metabolites. For many years well established and highly efficient methods such as UV spectroscopy, high performance liquid chromatography, gas chromatography, liquid chromatography, mass spectrometry and capillary electrophoresis have been used for determination. In the last years, near infrared sp Read More

Polyphenols, good antioxidants, exist widely in plants and food resources. The separation methods of polyphenols from crude food and plant materials are reviewed. The separation methods reviewed include the pre-concentration by extraction methods (traditional extraction, SPE, and other extraction methods) and further separation by chromatography (HPLC, UHPLC, GC, column chromatography, TLC, and CCC) or ot Read More

Styrene is a commercially important chemical widely used, whose metabolic pathway in humans leads to mandelic (MA) and phenylglyoxylic (PGA) acids, whose total concentration is the dose biomarker suggested by ACGIH for occupational exposure. Non occupational exposure to styrene is uncommon, but nevertheless a background value is always found in human urine. Most analytical methods applied to workers biomonito Read More

The aims of this research were to develop and validate a simple, sensitive method to determine un-conjugated urinary cotinine (COT-U) levels and to investigate its ability to discriminate active and environmental tobacco smoke (ETS) exposure. For this assay, urine was diluted with water, cotinine-d3 was added as an internal standard, and the sample was separated by a C18 column and analysed by triple quadrupole mass Read More

The thiobarbituric acid (TBA) reaction with malondialdehyde (MDA) is commonly used to measure free radical- mediated oxidative changes in lipids containing polyunsaturated fatty acids (PUFA). This test has had a broad range of applications since it was introduced in 1949; among others, researchers have used this test to evaluate toxic outcomes of chemical exposure in many environmental and occupational settings. Ho Read More

Biological monitoring usually relies on the collection of blood and urine samples. Although being non-invasive and providing an inextinguishable sampling pool, the analysis of exhaled breath is not well established. A gas phase measurement is, however, inherently simpler than the analysis of complex biological fluids, and modern methods have identified hundreds of volatile compounds in the breath of persons exposed to nor Read More

Formaldehyde (FA) ranks 25th in the overall U.S. chemical production, with more than 5 million tons produced each year. Given its economic importance and widespread use, many people are exposed to FA occupationally. Recently, based on the correlation with nasopharyngeal cancer in humans, the International Agency for Research on Cancer (IARC) confirmed the classification of FA as a Group I substance. Considering t Read More

New separations methods are required that meet requirements of contemporary technology such as low cost, speed, and portability of instruments. Ion mobility spectrometry (IMS) complies with these requirements. In this work, IMS was modified by introducing nitrobenzene (NB) into the buffer gas of a mobility spectrometer to differentially increase the drift times of test compounds. Ion mobilities of tetramethyla Read More

Bee losses associated with colony collapse disorder (CCD) has become a serious worldwide problem. Over 60 contributing factors of CCD have been identified, being one of them the pesticide exposure, and particularly to neonicotinoid pesticides as imidacloprid. So, it is interesting to study its possible presence in beeswax, as this product could be a storage location of this pesticide not only for its original beehive, but for other Read More

This study represents the first report on the development and validation of a highly sensitive fluorimetric method for determination of cinacalcet hydrochloride (CIN) in tablets and plasma. The method was based on nucleophilic substitution reaction of CIN with 7-chloro-4-nitrobenzoxadiazole (NBD-Cl) in an alkaline buffered medium (pH 9) to form a highly fluorescent derivative that exhibited maximum fluorescence intensity at Read More

The adsorption parameters of Pb(II) on the Amberlyst 36 were investigated and solid phase extraction was applied for the preconcentration of lead ions. Flame atomic absorption spectrometry was used for detection. The recovery of lead at optimum parameters such as pH (2), elution solution type and volume (5 mL of 3 mol/L HCl solution), flow rate (3 mL/min) etc. was obtained as (98.4±1.6) % at confidence level of 95% for ei Read More