Chapter 1 - Flow Injection Analysis: Its Origins and Progress

The ever increasing demand for rapid, cost-effective, practically-safe, and environmentally-benign analytical methods has aroused researchers to develop automated, miniaturized, versatile, and inexpensive analytical techniques. Flow injection (FI) techniques were well-established to meet the requirements of modern chemical analysis. The family of FI techniques includes three generations, flow injection analysis (FIA), sequential injection analysis (SIA), and bead injection analysis (BIA). In addition, new versions of SIA, micro-SIA-lab-on-valve (μSIA-LOV), and sequential injection chromatography (SIC), have recently been developed for more downscaling analysis and broadening applications. In the literature, we have not found a comprehensive and updated manuscript presenting all generations and recent versions of FI techniques. Therefore, the current manuscript briefly demonstrates the principles, developments, and applications of the FI techniques along with their consequent generations and recent versions.

A rapid and precise assay for peroxide as ‘active oxygen’ in products, by flow injection analysis in a high pressure system with spectrophotometric detection

For more than a decade, immunoassay methods have held great promise for use not only in their classic clinical applications but also in food, pesticides, process and quality control, industrial fermentations, etc. A great number of publications have appeared in these fields. Flow injection analysis (FIA) is a technique that allows the automatic analysis of a large number of samples and/or continuous monitoring, and it has been proven to be applicable to a variety of analytical problems. Nevertheless, antibody-supported flow injection systems have received relatively little attention. Only recently, the advantage of the specificity inherent to most immune reactions began to be exploited in FIA procedures. Flow injection coupled to immunoassays (FIIA) is arising as a powerful tool for the development of analytical protocols, and the application of FIA techniques is expected to contribute enormously in improving the speed and quality of immunoassays. This article gives an overview on the application...

Objective To establish a catalytic spectrophotometric method for determination of iodine in water without the use of highly toxic arsenic reagents with good precision and accuracy. Methods A new flow injection catalytic spectrophotometry method for determination of iodine in water was established by combining flow injection analysis (FIA) with a new catalytic spectrophotometry for determination of iodine with no need of arsenic reagent. The standard curve linearity, sample detection limit, precision and accuracy of different iodine content ranges(0 - 250, 0 - 1 200 μg/L) were tested. The test result was compared with that of the arsenic-based catalytic spectrophotometry recommended by the iodine deficiency disorders monitoring program in China(recommended monitoring method). Results A calibration relation of C = aA2 + bA + d (C: iodine concentration, A: measuring absorbance peak area from FIA) of the new method existed in the range of 0 - 250 and 0 - 1 200 μg/L. The linear correlative coefficient were both 0.999 9. The detection limit for iodine in water was 0.3 μg/L. The FIA peak shape of the sample tube with the lowest content is determined, and the sensitive iodine signal is detected. The water samples with different iodine content ranges were determined in parallel for 6 times, and the coefficient of variation (CV) was 0.2% - 2.7%; the recoveries ranged from 95.0% to 105.0%, and the total average recovery was 100.3%. The measured values of water iodine standard material GBW 09113e [(8.2 ± 1.2) μg/L] and GBW 09114d [(62.0 ± 6.0) μg/L] in the standard curve of different iodine contents were all within the uncertainty range of the given value. There was no significant difference between the results of recommended monitoring method and the new method(t = 0.781, P > 0.05). Conclusions The new method for measuring water iodine has a wide standard curve range, high sensitivity, and good precision and accuracy. The instrument is easy to operate, and no need for toxic arsenic reagent. The method is a reliable method for water iodine detection. Key words: Iodine; Water; Arsenic; Flow injection analysis; Catalytic spectrophotometry

Incorporation of a liquid waveguide capillary flow cell into a flow injection instrument enhances the sensitivity of flow injection analysis with spectrophotometric detection by two orders of magnitude. Nitrite determination at nM levels has been used to demonstrate the feasibility of this novel technique for trace analysis. Combining the long pathlength spectrophotometry with flow injection analysis, this technique has advantages of low detection limit, good precision and high sample throughput.

Pungency evaluation of onion cultivars from the Venezuelan West-Center region by flow injection analysis–UV–visible spectroscopy pyruvate determination

Abstract The steam distillation technique for the quantification of soil mineral nitrogen is not well adapted to estimate very low levels of NH4 + and NO3 −such as those found in tropical pastures. In this paper we describe a flow injection analysis (FIA) technique for the direct estimation of soil ammonium in potassium chloride extracts. The technique is based on the salicylate/hypochlorite colorimetric reaction with the resulting colouration read at 647 nm. The speed of the reaction was increased by immersing the reaction coils in a water bath maintained at 70°C. The technique was capable of accurately quantifying ammonium to concentrations as low as 0.05 mg NH4+‐N/L (equivalent to 0.25 mg NH4 +‐N/g dry soil) and sample thoughputs of at least 60 samples per hour could be achieved. It was found that amino acids would also give a positive colorimetric reaction but that in the ten tropical soils examined this was not a significant source of error.

Simultaneous potentiometric determination of ClO 3−–ClO 2− and ClO 3−–HClO by flow injection analysis using Fe(III)–Fe(II) potential buffer

A community-wide intercomparison exercise for the determination of dissolved iron in seawater

Standard additions in flow injection analysis with atomic absorption spectrometry

A gravity-induced flow injection system for surface plasmon resonance biosensor

A state-of-the-art strategy for the determination of lipase activity in pancreatic preparations using flow injection analysis (FIA) with electrochemical detection (FIA-ED) is described. The procedure is based on the enzymatic reaction of a specific substrate (1,3-dilinoleoyl-glycerol) with lipase from porcine pancreas and determination of enzymatically formed linoleic acid (LA) at +0.4 V by applying a cobalt (II) phthalocyanine-multiwalled carbon-nanotubes modified carbon paste electrode (Co(II)PC/MWCNT/CPE). In order to get a high-performance analytical method, sample preparation, flow system, and electrochemical conditions were optimized. Under optimized conditions the lipase activity of porcine pancreatic lipase was calculated to be 0.47 units per mg lipase protein based on the definition that 1 unit hydrolyses 1 microequivalent linoleic acid from 1,3-dilinoleoyl-glycerol per 1 min at pH 9 and 20 °C (kinetic measurement: 0–25 min). Moreover, the developed procedure was shown to be easily adaptable for the fixed-time assay (incubation time 25 min) as well. In this case, linear correlation between flow signal and lipase activity was found in the range from 0.8 to 18 U L−1. LOD and LOQ were determined to be 0.3 U L−1 and 1 U L−1, respectively. The kinetic assay was further preferred for the determination of lipase activity in commercially available pancreatic preparations. The lipase activities of all preparations obtained by the present method were found to be in good correlation with those obtained by the titrimetric method and declared by manufacturers.

Recording the real sample distribution and concentration/time functions in flow injection analysis

A rapid profiling of gallotannins and flavonoids of the aqueous extract of Rhus coriaria L. by flow injection analysis with high-resolution mass spectrometry assisted with database searching

Hollow fiber-based liquid-liquid-liquid microextraction (HF-LLLME) followed by flow injection analysis and diode array detection (FIA-DAD) was applied as a simple and sensitive quantitative method for the determination of phenazopyridine in urine and plasma samples. Flow injection system included a conventional HPLC system (without a chromatographic column) and a diode array detector. The extraction of phenazopyridine was carried out using diphenyl ether as the organic phase for filling the pores of the hollow fiber wall, and 0.1 M H(2)SO(4) solution as acceptor phase in the lumen of the fiber. The factors affecting the HF-LLLME and flow injection analysis including type of organic solvent, pH of donor phase, extraction temperature, extraction time, stirring rate, and pH of mobile phase were investigated and the optimal extraction conditions were established. With the consumption of 5 mL of sample solution, the enrichment factor was about 230. The limit of detection was 0.5 μg/L with inter- and intra-day precision being (RSD%) 6.9 and 4.9, respectively. Excellent linearity was found between 5 and 200 μg/L.