Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Flow Injection Analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources
PubMed1997

Novel DNA detection system of flow injection analysis (2). The distinctive properties of a novel system employing PNA (peptide nucleic acid) as a probe for specific DNA detection.

In order to realize immediate detection of a double stranded DNA amplified by Polymerase Chain Reaction (PCR), we applied Peptide Nucleic Acid (PNA) to the probe of DNA detection system using Surface Plasmon Resonance (SPR). We report our success in immediate detection of PCR products solution with high sequence-specificity.

Bacterial Toxins↗
PubMed2002

Rapid isolation of biomarkers for compound specific radiocarbon dating using high-performance liquid chromatography and flow injection analysis-atmospheric pressure chemical ionisation mass spectrometry.

Repeated semi-preparative normal-phase HPLC was performed to isolate selected biomarkers from sediment extracts for radiocarbon analysis. Flow injection analysis-mass spectrometry was used for rapid analysis of collected fractions to evaluate the separation procedure, taking only 1 min per fraction. In this way 100-1000 microg of glycerol dialkyl glycerol tetraethers, sterol fractions and chlorophyll-derived phytol were isolated from typically 100 g of marine sediment, i.e., in sufficient quantities for radiocarbon analysis, without significant carbon isotopic fractionation or contamination.

Biomarkers↗
PubMed2003

An overview of qualimetric strategies for optimisation and calibration in pharmaceutical analysis using flow injection techniques.

Flow Injection analysis represents an attractive tool because of its great advantages, such as versatility, speed, high sampling rate and wide applicability in the field of pharmaceutical analysis. However, due to the inherent characteristics of the technique, the choice of the best set of operational and chemical conditions is complicated and the conventional univariate optimisation method present some limitations, mainly due to fact that the interdependence of variables is not considered. In relation to the calibration process, because of the transient character of the signals obtained using FIA manifolds coupled with different detection techniques, different strategies can be used in calibration to solve some problems related to the nature of the signal thereby improving the performance characteristics of the method. This paper offers an overview of different methodologies used in optimisation based on the use of statistically designed experiments and some strategies developed for calibration applied to the analysis of pharmaceuticals.

Calibration↗
PubMed2002

Synthesis and preliminary analytical evaluation of the chemiluminescence from (4-[4-(dichloromethylsilanyl)-butyl]-4'-methyl-2,2'-bipyridyl)bis(2,2'-bipyridyl)ruthenium(II) covalently bonded to silica particles.

This paper describes, for the first time, a simple and effective synthetic route for covalently bonding the chemiluminescence reagent, (4-[4-(dichloromethylsilanyl)-butyl]-4'-methyl-2,2'-bipyridyl)bis(2,2'-bipyridyl)ruthenium(II) onto silica particles. The subsequent preparation of chemically regeneratable detection cells and their preliminary analytical evaluation with both sequential injection analysis and flow injection analysis are also reported. Unoptimised analytical figures of merit were established for standard solutions of codeine and sodium oxalate with detection limits calculated from three times the standard deviation of the blank signal, of 1 x 10(-8) M and 3 x 10(-7) M respectively. The chemically immobilised reagent exhibited some intriguing solvent and kinetic effects, which are also briefly discussed.

Journal Article↗
PubMed1996

Physiological effects of nitrogen starvation in an anaerobic batch culture of Saccharomyces cerevisiae.

The effects of nitrogen starvation on the anaerobic physiology of Saccharomyces cerevisiae were studied in cells cultivated in a bioreactor. The composition of the mineral medium was designed such that the nitrogen source became depleted while there was still ample glucose left in the medium. The culture was characterized by acoustic gas analysis, flow injection analysis and HPLC analysis of extracellular substrates and metabolites. During the cultivation, the macromolecular composition of the cells was analysed with respect to the cellular content of RNA, protein, trehalose and glycogen. During exponential growth under anaerobic conditions, the maximum specific growth rate conditions. Depletion of ammonium in the medium led to an abrupt decrease (mumax) of S. cerevisiae CBS 8066 (0.46 h-1) was identical to the mumax determined under aerobic in the flux through glycolysis. Subsequently, a continuous decrease in the carbon dioxide evolution rate, caused by catabolite inactivation of the hexose-transport system, was observed. The apparent half-life of the transport system under nitrogen starvation was 13 h. During the exponential growth phase, the cellular content of RNA and protein was 15% (w/w) and 60% (w/w), respectively. At the end of the cultivation where the cells had been starved of nitrogen for 18 h, the cellular content of RNA and protein had decreased to 4% (w/w) and 22% (w/w), respectively. The intracellular carbohydrate content increased dramatically as trehalose and glycogen accumulated to final concentrations of 7% (w/w) and 25% (w/w), respectively. Glycerol formation during nitrogen starvation was higher than that accounted for by the formation of organic acids, suggesting a protein turnover of approximately 6% h-1. The growth energetics of S. cerevisiae CBS 8066 also changed as a result of nitrogen starvation, and YxATP was observed to increase from 80 mmol g-1 during the exponential growth phase to more than 130 mmol g-1 towards the end of the cultivation. The presented results illustrate the effect of nitrogen starvation on glycerol formation, protein turnover, catabolite inactivation of the sugar-transport system, the cellular composition, the cell cycle and growth energetics.

Ammonia↗
PubMed2006

Automated on-line renewable solid-phase extraction-liquid chromatography exploiting multisyringe flow injection-bead injection lab-on-valve analysis.

In this paper, the third generation of flow injection analysis, also named the lab-on-valve (LOV) approach, is proposed for the first time as a front end to high-performance liquid chromatography (HPLC) for on-line solid-phase extraction (SPE) sample processing by exploiting the bead injection (BI) concept. The proposed microanalytical system based on discontinuous programmable flow features automated packing (and withdrawal after single use) of a small amount of sorbent (<5 mg) into the microconduits of the flow network and quantitative elution of sorbed species into a narrow band (150 microL of 95% MeOH). The hyphenation of multisyringe flow injection analysis (MSFIA) with BI-LOV prior to HPLC analysis is utilized for on-line postextraction treatment to ensure chemical compatibility between the eluate medium and the initial HPLC gradient conditions. This circumvents the band-broadening effect commonly observed in conventional on-line SPE-based sample processors due to the low eluting strength of the mobile phase. The potential of the novel MSFI-BI-LOV hyphenation for on-line handling of complex environmental and biological samples prior to reversed-phase chromatographic separations was assessed for the expeditious determination of five acidic pharmaceutical residues (viz., ketoprofen, naproxen, bezafibrate, diclofenac, and ibuprofen) and one metabolite (viz., salicylic acid) in surface water, urban wastewater, and urine. To this end, the copolymeric divinylbenzene-co-n-vinylpyrrolidone beads (Oasis HLB) were utilized as renewable sorptive entities in the micromachined unit. The automated analytical method features relative recovery percentages of >88%, limits of detection within the range 0.02-0.67 ng mL(-1), and coefficients of variation <11% for the column renewable mode and gives rise to a drastic reduction in operation costs ( approximately 25-fold) as compared to on-line column switching systems.

Automation↗
PubMed1998

Determination of cyanide by a flow injection analysis-atomic absorption spectrometric method.

A new flow injection analysis (FIA) procedure is proposed for the indirect atomic absorption spectrometric determination of cyanide. The FIA manifold is based on the insertion of the sample into a distilled water carrier, then the sample flows through a solid-phase reactor filled with silver iodide entrapped in polymeric resin beads. The calibration graph is linear over the range 0.2-6.0 mg l-1 of cyanide (correlation coefficient 0.9974), the detection limit is 0.1 mg l-1, the sample throughput is 193 h-1 and the RSD is 0.8%. The method is simple, quick and more selective than other published FIA procedures. The reproducibility obtained by using different solid-phase reactors and solutions is in the range 2.2-3.1% (RSD). The method was applied to the determination of cyanide in commercial samples such as pharmaceutical formulations and industrial electrolytic baths.

Cyanides↗