Phosphate flow-injection analysis

Simultaneous determination of both cations and anions in acid rain has been achieved using a portable conductimetric ion-exclusion cation-exchange chromatographic analyzer.14 This system utilized the poly(meth-ylmethacrylate)-based weak acid cation exchange resin TSK-Gel OA-PAK-A, (Tosoh , Tokyo, Japan) with an eluent of tartaric acid-methanol-water. All of the desired species, 3 anions and 5 cations, were separated in less than 30 minutes detection limits were on the order of 10 ppb. Simultaneous determination of nitrate, phosphate, and ammonium ions in wastewater has been reported utilizing isocratic IEC followed by sequential flow injection analysis.9 The ammonium cations were detected by colorimetry, while the anions were measured by conductivity. These determinations could be done with a single injection and the run time was under 9 minutes. 

MWNTs favored the detection of insecticide from 1.5 to 80 nM with a detection limit of InM at an inhibition of 10% (Fig. 2.7). Bucur et al. [58] employed two kinds of AChE, wild type Drosophila melanogaster and a mutant E69W, for the pesticide detection using flow injection analysis. Mutant AChE showed lower detection limit (1 X 10-7 M) than the wild type (1 X 10 6 M) for omethoate. An amperometric FIA biosensor was reported by immobilizing OPH on aminopropyl control pore glass beads [27], The amperometric response of the biosensor was linear up to 120 and 140 pM for paraoxon and methyl-parathion, respectively, with a detection limit of 20 nM (for both the pesticides). Neufeld et al. [59] reported a sensitive, rapid, small, and inexpensive amperometric microflow injection electrochemical biosensor for the identification and quantification of dimethyl 2,2 -dichlorovinyl phosphate (DDVP) on the spot. The electrochemical cell was made up of a screen-printed electrode covered with an enzymatic membrane and combined with a flow cell and computer-controlled potentiostat. Potassium hexacyanoferrate (III) was used as mediator to generate very sharp, rapid, and reproducible electric signals. Other reports on pesticide biosensors could be found in review [17],... 

Figure 2.5. Analytical manifolds for the determination of phosphate by flow injection analysis (a) and reverse flow injection (b). The symbols S, M, and A are the seawater, mixed reagent, and the ascorbic acid solutions. The pump injection valve and detector are represented by P, I, and D, respectively. W = waste. From [177]... 

Johnson and Petty [177] adapted reverse flow injection analysis to the well-known Murphy and Riley [178] colorimetric phosphomolybdate reduction method for the determination of phosphate. 

Figure 2.5a and b show flow sheets for the determination of phosphate by flow injection analysis and reversed flow injection analysis, respectively. 

Some coupled systems allow measurement of the main N and P forms (nitrate, ammonia and orthophosphates) [22,27,29], among which is a system based on membrane technology in combination with semi-micro continuous-flow analysis (pCFA) with classical colorimetry. With the same principle (classical colorimetry), another system [30] proposes the measurement of phosphate, iron and sulphate by flow-injection analysis (FIA). These systems are derived from laboratory procedures, as in a recent work [31] where capillary electrophoresis (CE) was used for the separation of inorganic and organic ions from waters in a pulp and paper process. Chloride, thiosulphate, sulphate, oxalate,... 

In a further method [67] for the determination of ammonium lactate extractable (i.e. available) phosphorus in soils, the sample 5g is extracted with 100ml acidic ammonium lactate and then phosphate determined by flow-injection analysis using the stannous chloride method [68]. 

Data obtained by the standard addition method with a tyrosinase sensor in flow injection analysis. Experimental conditions 0.1 M phosphate buffer pH 6.0, injection volume 500 )ttl, flow rate 0.5 ml min V ppm(mgF ), ppb (/igl ). 

Flow-injection analysis (FIA) is a technique for automating chemical analyses. The principles of FIA are reviewed here. Methods for applying FIA to the anayses of nitrate, nitrite, phosphate, silicate, and total amino acids in seawater are examined. Analyses of other nutrients, metals, and carbonate system components are also discussed. Various techniques to eliminate the refractive index effect are reviewed. Finally, several examples of the application of FIA to oceanographic problems are presented. 

ADP AFP ab as ALAT AP ASAT ATP BQ BSA CEH CK CME COD con A CV d D E E EC ECME EDTA EIA /e FAD FET FIA G GOD G6P-DH HBg HCG adenosine diphosphate a-fetoprotein antibody antigen alanine aminotranferase alkaline phosphatase aspartate aminotransferase adenosine triphosphate benzoquinone bovine serum albumin cholesterol ester hydrolase creatine kinase chemically modified electrode cholesterol oxidase concanavalin A coefficient of variation (relative standard deviation) layer thickness diffusion coefficient enzyme potential Enzyme Classification enzyme-chemically modified electrode ethylene diamine tetraacetic acid enzyme immunoassay enzyme loading factor flavin adenine dinucleotide field effect transistor flow injection analysis amplification factor glucose oxidase glucose-6-phosphate dehydrogenase hepatitis B surface antigen human chorionic gonadotropin... 

K.S. Johnson, R.L. Petty, Determination of phosphate in sea water by flow injection analysis with injection of reagent, Anal. Chem. 54 (1982) 1185. 

P. Linares, M.D. Luque de Castro, M. Valcarcel, Simultaneous determination of pyridoxal and pyridoxal-5-phosphate in human serum by flow injection analysis, Anal. Chem. 57 (1985) 2101. 

M. Kamaya, K. Nagashima, E. Ishii, Determination of sulphate and phosphate by flow-injection analysis using a barium chloranilate packed column, Fresenius J. Anal. Chem. 347 (1993) 409. 

Y. Narusawa, T. Hashimoto, Simultaneous determination of phosphate, silicate, and arsenateby on-line column flow injection analysis, Chem. Lett. 16 (1987) 1367. 

J. Ruzicka, E.H. Hansen, Flow injection analysis. Part VI. The determination of phosphate and chloride in blood serum by dialysis and sample dilution, Anal. Chim. Acta 87 (1976) 353. 

Recently, Karmarkar reported an impressive dual IC-flow injection analysis (FIA) method for the sequential determination of anionic (nitrate and phosphate) and cationic (ammonium) nutrients in wastewater samples. The dual system was based upon the use of an anion exchange column (Lachat QS-A5) and two detectors, one suppressed conductivity detector using a Lachat Instruments QE-Al small suppressor cartridge, which is regenerated between samples, and a second visible absorbance detector. Upon injection of the sample the conductivity detector was switched off line and the nonretained ammonium was passed through the analytical column and detected by the visible absorbance detector, following an on hne colorimetric reaction. The conductivity detector was then immediately switched on hne to detect the retained nutrient anions. The method reported detection limits for phosphate of 0.006 mg/1 phosphate. 

Y. Hirai, N. Yoza, and S. Ohashi, Flow Injection Analysis of Phosphates in Environmental Waters [in Japanese]. Bunseki Kagaku, 30 (1981) 465. 

S. Motomizu, T. Wakimoto, and K. Toei, Determination of Trace Amounts of Phosphate in River Water by Flow Injection Analysis. Talanta, 30 (1983) 333. 

H. Engelhard and R. Klinkner, Phosphate Determination by Flow Injection Analysis with Geometrically Deformed Open Tubes [in German]. Fre-senius Z. Anal. Chem., 317 (1984) 671. 

L. C. Davis and G. A. Radke, Chemically Coupled Spectrophotometric Assays Based on Flow Injection Analysis. Determination of Nitrogenase by Assays for Creatinine, Ammonia, Hydrazine, Phosphate and Dithionite. Anal. Biochem., 140 (1984) 434. 

P. Linares, M. D. Luque de Castro, and M. Valc rcel, Fluorimetric Determination of Pyridoxal and Pyridoxal-5-Phosphate by Flow Injection Analysis. Anal. Lett. B, 18 (1985) 67. 

O. R0yset, Determination of Phosphate Species in Nutrient Solutions and Phosphorous in Plant Material as Phosphovanadomolybdic Acid by Flow Injection Analysis. Anal. Chim. Acta, 178 (1985) 217. 

E. A. Jones, The Determination, by Flow Injection Analysis, of Fluoride, Chloride, Phosphate, Ammonia, Nitrite, and Nitrate. Rep.-MINTEK (S. Africa), M200 (1985) 65. 

H. Nakajima and H. Ichiki, The Rapid Examination for Phosphate Fertility in Grazing and Farm Land Soil Derived from Neutral Volcanic Ash. 3. Application of Flow Injection Analysis to 10 H2SO4 Extraction [in Chinese]. Tohoku Agric. Res., 37 (1985) 135. 

D. K. Morgan, Prederivatization Liquid Chromatography for the Determination of Inorganic Phosphate and of Methylmalonic Acid and Flow Injection Analysis with Infrared Detection. Diss. Abstr. Int. B, 46 (1986) 3421. (Ph.D. Thesis, Miami Univ., Oxford, OH, USA). 

L. Xu, X. Liu, Y. Yang, and F. Yan, Determination of Total Phosphate in Plant Samples by Flow Injection Analysis [in Chinese]. Dongbei Linx-ueyuan Xuebao, 13 (1985) 33. 

G. Wei and H. Ma, Determination of Total Phosphate in Samples from Trees by Flow Injection Analysis—Molybdenum Yellow Photometric Method [in Chinese]. Linye Daxue Xuebao, 3 (1986). 

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