Determination in natural water

Alkalinity. The alkalinity of a water sample is its acid-neutrali2ing capacity. Bicarbonate and carbonate ions are the predominant contributors to alkalinity in most waters, and their chemical equiUbria generally maintain the pH of 5—9. The presence of enough hydroxide ion to affect the alkalinity determination in natural waters is rare. SiUca, borate, or phosphate do contribute to the overall alkalinity if present in large enough quantities. 

SAMPLE STORAGE AND ARSENIC DETERMINATION IN NATURAL WATERS... 

E. Mallat, D. Barcel6, C. Barzen, G. Gauglitz, and R. Abuknesha, Immunosensors for pesticide determination in natural waters. Trac-Trends Anal. Chem. 20, 124-132 (2001). 

A selective reaction takes place between H2O2 and 10-methyl-9-(p-formylphenyloxy-carbonyl)acridinium trifluoromethanesulfonate (123) in basic solution with CL emission at about 470 nm. A proposed mechanism for CL is depicted in Scheme 2. No catalyst other than an alkali is required for the process to take place. The LOD is about 5 nM, with linearity np to 60 (xM. It should be pointed out that the LOD is dictated by the technical capability of obtaining a blank of water devoid of H2O2. The method was applied for H2O2 determination in natural waters. ... 

T. Stoichev, R. C. Rodriguez-Martin-Doimeadios, D. Amouroux, N. Molenat and O. F. X. Donard, Application of cryofocusing hydride generation and atomic fluorescence detection for dissolved mercury species determination in natural water samples, J. Environ. Monit., 4, 2002, 517-521. 

T.G. Laperdina, Mercury Determination in Natural Waters, Nauka, Novosibirsk, 2000 (in Russian). 

Sheng, G., M. Zhang, and H. Yu. 2007. A rapid quantitative method for humic substances determination in natural waters. Anal. Chim. Acta 592 162-167. 

Because of the low wavelengths of its main resonance lines, tellurium is never routinely determined by flame AES, but the element may be determined with moderate sensitivity by flame AAS or AFS techniques, at 214.3 nm in an oxidizing air-acetylene flame. The detection limit is generally around 100 ng ml-1, which is inadequate for almost all environmental applications unless the element is pre-concentrated by a substantial factor.1 However, hydride generation plus AFS or AAS yields much more useful detection limits. Even so, pre-concentration may be necessary if the element is to be determined in natural waters, for example by extraction as the tributylphosphate complex.50 The... 

Arsenic was also determined in natural water after flotation of the ion-associate with Malachite Green [52], and Crystal Violet [90], and after extraction with Methylene Blue [91]. 

Molybdenum was determined in natural waters with the aid of CBP and Zephiramine, after selective preconcentration on a Sephadex gel column [63]. 

The use of alizarin-lanthanum complexonate has been described for the determination of fluorine in soil [1] and plant samples [2]. The method for fluoride determination in natural waters based on the decrease in colour intensity of the Th bromocresol orange complex in the presence of F was presented [3]. 

Ferreira, S.L.C., Ferreira, J.R., Danlas, A.F., Lemos, V.A., Araujo, N.M.L. and Spinola Costa, A.C., 2000, Copper Determination in Natural Water Samples by Using FAAS... 

Kolling, M., 2000. Comparison of Different Methods for Redox Potential Determination in Natural Waters. In Schuring et al. (Eds.) Redox - Fundamentals, Processes and Applications. Springer, Berlin, Heidelberg etc., pp. 42-54. 

Table 3.72. Chemical parameters commonly determined in natural waters and water supplies... 

P. Langer, Investigations for Sulphate Determination in Natural Waters by Means of Flow Injection Analysis [in German]. Tech. Univ. Berlin, Germany (1983). (M.Sc. Thesis). 

Cavari, B. and Phelps, G., 1977. Sensitive enzymatic assay for glucose determination in natural waters. Appl. Environ. Microbiol., 33 1237—1243. 

Hicks, S.E. and Carey, R.G., 1968. Glucose determination in natural waters. Limnol. Oceanogr., 13 361—363. 

The direct species-specific techniques would be the ideal speciation procedure, providing identification and quantification of a given individual species in situ without any sample treatment. The techniques of this type, more used for individual metal-containing species determination, are electroanalytical in nature (e.g., ion-selective electrodes have been used for determining major free alkali ion determinations in natural waters and serum). More sensitive voT tamperometric redissolution techniques can be useful for speciation of free and labile forms of metals (or their different oxidation states) in waters. 

Mallat E and Barcelo D (2001) Immunosensors for pesticide determination in natural waters. Trends in Analytical Chemistry 20 124—132. 

C. Henriquez, L.M. Laglera, M.J. Alpizar, J. Calvo, F. Arduini, V. Cerd Cadmium determination in natural water samples with an automatic multisyringe flow injection system coupled to a flow-through screen printed electrode, Talanta 96 (2012) 140—146. 

W.R. Melchert, C.M.C. Infante, F.R.P. Rocha, Development and critical comparison of greener flow procedures for nitrite determination in natural waters, Microchem. J. 85 (2007) 209-213. 

In our work with antimony determination in natural waters, we have not experienced serious contamination problems. We have used Niskin and Teflon-coated Go-Flo samplers (General Oceanics) and polycarbonate COC and TPN samplers (Hydrobios) for the collection of seawater samples without evidence of contamination resulting from any of these sampler types (see also Chapter 1). 

Pena-Pereira, F. Costas, M. Bendicho, C. Lavilla, I. A Solvent Microextraction Approach for Envirornnenlal Analysis Colorimetric Assay for Phosphoms Determination in Natural Waters. J. Chem. Educ. 2014,91, 586-589. 

Multicommutation also allows implementation of procedures for assessment of accuracy. For example, the same analyte can be determined by two different methods with the same flow network. In this way, a multicommutated flow manifold was proposed for chloride determination in natural waters with different sample matrices based on the spectrophotometric procedure using mercury(II) thiocyanate and the turbidimetric method using silver nitrate [19]. Moreover, in-line addition/recovery tests were implemented for every assayed sample in order to detect matrix effects. 

Boyle, E. A., B. Handy, and A. Geen. 1987. Cobalt determination in natural waters using cation-exchange liquid chromatography with luminol chemiluminescence detection. Anal. Chem. 59 1499-1503. 

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