Showing papers in "Analytica Chimica Acta in 2003"

TL;DR: In this paper, the authors examined the factor analysis of matrices where the proportion of signal and noise is very different in different columns (variables) and found that if a few weak variables are scaled to too high a weight in the analysis, the errors in computed factors would grow, possibly obscuring the weakest factor(s) by the increased noise level.

TL;DR: The multivariate resolution methods have been the tools designed to unravel this pure compound information from the non-selective mixed original experimental output as discussed by the authors, which has allowed the successful application of these methodologies to chemical problems as complex and diverse as the interpretation of protein folding processes or the resolution of spectroscopic images.

TL;DR: In this paper, a typical room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6], was used as an alternative solvent to study liquid/liquid extraction of heavy metal ions.

TL;DR: In this article, different synthesis routes and deposition methods of polyaniline (PANi) as sensitive layer, as well as the various techniques to monitor the gas adsorption on polyanoiline are reviewed.

TL;DR: In this article, a method for sequential selective extractions (SSEs) for Hg in geological solids, validated with extensive quality assurance procedures, was presented, where Mercury was separated into fractions which "make sense" biogeochemically, rather than being identified by specific compounds.

TL;DR: In this paper, a detailed comparison between the original BCR sequential extraction procedure, step 2, which involves treatment with 0.1 mol l(-1) hydroxylammonium chloride at pH 2, and the revised BCR procedure (step 2: 0.5 mol l (-1) HCL at pH 1.5).

TL;DR: A variety of new nanoparticle/polynucleotide assemblies for advanced electrical detection of DNA sequences based on innovative and powerful nanoparticle-based electrochemical DNA hybridization assays based on a variety of detection schemes are reviewed.

TL;DR: In this article, a new solid-phase extraction system for HPLC determination of di-ethyl-phthalate, di-n-propylphthalate and di-cyclohexyl-phthalates was developed.

TL;DR: In this article, the multivariate statistical techniques principal component analysis (PCA), Q-mode factor analysis (QFA), and correspondence analysis (CA) were applied to a dataset containing trace element concentrations in groundwater samples collected from a number of wells located downgradient from the potential nuclear waste repository at Yucca Mountain, Nevada.

TL;DR: In this article, a simple routine procedure to preserve, decarbonate and analyse low-carbonated filters of suspended particulate organic matter (POM) for particle organic carbon and nitrogen content, δ 13 C and δ 15 N.

TL;DR: In this paper, a molecular imprinted adsorbent was used to remove heavy metal ions with high selectivity, achieving an adsorption equilibria in about 1h.

TL;DR: In clinical research the sensitivity, dynamic range and diversity of chemiluminescent assays has led to a vast range of applications, notably in protein and nucleic acid blotting, microarray-based assays, monitoring reactive oxygen species, and as detection reactions for substances separated by HPLC, capillary electrophoresis (CE), and flow-injection analysis.

TL;DR: A review of analytical use of LEDs that has been advanced in the last decade is presented in this article, where LED-based absorbance measurement and its use in pedagogy, titrations, in providing immunity to refractive index and turbidity effects, in field and process analysis, in capillary electrophoresis, in liquid-liquid extraction systems, in film and drop-based analytical systems and with liquid core waveguides (LCWs) are discussed.

TL;DR: In this article, a sensor array comprising 23 potentiometric cross-sensitive chemical sensors and pattern recognition and multivariate calibration data processing tools was applied to the analysis of Italian red wines.

TL;DR: In this paper, the authors used polyvinyl chloride (PVC) matrix membranes with neutral carrier, monoaza-12-crown-4 as ionophore, and demonstrated good discriminating power over a number of monovalent, divalent and trivalent cations.

TL;DR: The method presented in this work requires neither data reduction nor preprocessing, e.g. peak detection, and the peak alignment routine is applied to NMR metabonomic data.

TL;DR: An easy-to-use test system for detecting receptor–ligand interactions on the single molecule level using atomic force microscopy (AFM) and it is concluded that this system is well suited as calibration or start-up kit for single molecule recognition force microscopeopy.

TL;DR: In this paper, the authors claim that proper analytical chemistry (1) must in fact incorporate a chemometric approach and (2) that there are several significant advantages of doing so, and an indirect route will be taken, where the most important benefits of chemometric methods are discussed using small illustrative examples.

TL;DR: In this article, the authors evaluated the efficiency of consecutive extraction using several individual extractants or solvent mixtures: water, methanol:water (1: 1, 9:1, 1: 1-9:1 in two consecutive steps) and phosphoric acid for arsenic species extraction from rice, fish and chicken tissue, and soil samples.

TL;DR: A review of the state-of-the-art on polysaccharide analysis can be found in this paper, focusing on starch and cellulose derivatives and the use of specific hydrolysing enzymes facilitating their analysis.

TL;DR: In this paper, variable stability (VAST) scaling is proposed to weight each variable according to a metric of its stability, which improves the class distinction and predictive power of PLS-DA models.

TL;DR: In this article, the authors refer to the specific field of forensic toxicology and doping control in sports and present a set of confirmatory packages that are briefly exposed, compared and evaluated for their future application to the newest LC-MS techniques that are more frequently used within these critical fields of expertise.

TL;DR: In this article, analytical methods based on GC-MS and LC-MS for the determination of traces of 2,4,4′-trichloro-2′-hydroxydiphenyl ether (triclosan) and biphenylol in urban wastewater and marine sediments were developed.

TL;DR: In this article, the most sensitive analytical luminescence methods and their recent applications are reviewed with emphasis on most sensitive methods that can be expected to be useful in future microanalytical systems such as μ-TAS, lab-on-chip, point-of-care (POC) and high throughput screening (HTS) applications.

TL;DR: In this paper, the authors examined the use of PFE for the extraction of carotenoids in the green algae Haematococcus pluvialis and Dunaliella salina and kavalactones in Piper methysticum.

TL;DR: In this paper, the authors developed a new analytical methodology for the quantitative determination of carrageenans in industrial mixtures employing FTIR and multivariate regression (partial least squares, PLS), avoiding complex sample pre-treatment steps and reducing the turnaround time.

TL;DR: In this paper, a sensitive method for the quantitative analysis of all natural isoprenoid cytokinins in plant material by electrospray single-quadrupole mass spectrometry is presented.

TL;DR: In this article, a multi-wall carbon nanotube (MWNT) modified glassy carbon electrode (GCE) was described for the simultaneous determination of trace levels of cadmium and lead by anodic stripping voltammetry (ASV).

TL;DR: In this paper, the authors used partial least squares (PLS) regression to establish a relationship between soil reflectance spectra measured under field conditions and the organic matter and clay content of the soil.

TL;DR: In this article, principal component analysis (PCA), hierarchical cluster analysis (HCA) and k-nearest-neighbour (kNN) classification were applied to the data from the high-dose studies to reveal dose and time-related effects.