Water sample analysis

Trihalomethanes in Drinking Water (Sampling Analysis, Monitoring and Compliance), U.S. Envkonmental Piotection Agency, EPA/570/9-83-002, Washington, D.C., 1983. 

From a technical standpoint, this article emphasizes recent advances in sample preparation and instrumentation. A brief history of modern sample preparation techniques is covered, together with the impact of modern instrumentation on water sample analysis. 

Kopfler, F. C. Ringhand, H. P. Miller, R. G. In Organic Pollutants in Water Sampling, Analysis, and Toxicity Testing Suffet, I. H. Malaiyandi, M., Eds. Advances in Chemistry 214 American Chemical Society Washington, DC, 1986 Chapter 20. 

Type of data Data of the Irkutsk Ecological Service on Angara water quality control Results of water samples analysis ... 

Collect trip blanks for water sample analysis only when low level contamination is a matter of concern. 

Mercader, J.V. and A. Montoya. 1999. Development of monoclonal ELISAs for azinphos-methyl. II. Assay optimization and water sample analysis. J. Agric. Food Chem. 47 1285-1293. 

The mantra of sampling is to avoid introducing contamination during the sampling process. Samplers should not wear hand jewellery, and all sampling equipment must be free of contaminants and cleaned thoroughly between sample sites. Water sample analysis, in particular, involves determinations to very low concentrations and care should be taken to wash hands in the stream water first to remove any sweat or lotions (such as sun cream), and handling sample bottles must be done in such a way that the inside of bottles or lids are not touched by the hand. 

EPA. 1980. Water sample analysis-vinyl acetate spill pump-out well with attached it enviroscience analytical report HK-239. Washington, DC US Environmental Protection Agency, Office of Transportation and Safety. EPA/OTS no 88- 8000345. 

The same column conditions for the GC analysis of organochlorine compounds in this case are applied as are given under the clean-water sample analysis for OC compounds. 

Quantification Limits (ng/l) Obtained from Water Samples Analysis Using SPME with Different Fibers ... 

A series of surveys and reviews [28, 44, 45, 293] dealt with the simultaneous determination of a broad range of polar compounds in environmental samples by API interfaces. Possibilities and Hmitations of stmcture elucidation by bC-ion trap multiple mass spectrometry (bC-ITMS ) were the topic overview [38]. As shown later, pesticide residue analysis was the most frequent application of bC-MS in water sample analysis, as the number of review articles on the subject of pesticide analysis and their degradation products demonstrates [20, 22, 29, 30, 32, 199, 294], The analysis of dyes by means of API interfacing techniques was reviewed by three groups [43, 161, 200], while the bC-MS analysis of surfactants, as compounds of environmental concern, was comprehensively reviewed [21]. 

Two examples from the analysis of water samples illustrate how a separation and preconcentration can be accomplished simultaneously. In the gas chromatographic analysis for organophosphorous pesticides in environmental waters, the analytes in a 1000-mL sample may be separated from their aqueous matrix by a solid-phase extraction using 15 mb of ethyl acetate. After the extraction, the analytes are present in the ethyl acetate at a concentration that is 67 times greater than that in... 

Particulate gravimetry is commonly encountered in the environmental analysis of water, air, and soil samples. The analysis for suspended solids in water samples, for example, is accomplished by filtering an appropriate volume of a well-mixed sample through a glass fiber filter and drying the filter to constant weight at 103-105 °C. 

CO2 is determined by titrating with a standard solution of NaOH to the phenolphthalein end point, or to a pH of 8.3, with results reported as milligrams CO2 per liter. This analysis is essentially the same as that for the determination of total acidity, and can only be applied to water samples that do not contain any strong acid acidity. 

Analysis of a river water sample (pH of 7.49) gives the following results. ... 

A spike recovery for the analysis of chloride in well water was performed by adding 5.00 mb of a 25,000-ppm solution of Ck to a 500-mL volumetric flask and diluting to volume with the sample. Analysis of the sample and the spiked sample resulted in chloride concentrations of 183 ppm and 409 ppm, respectively. Determine the percent recovery of the spike. 

Preparation of soil—sediment of water samples for herbicide analysis generally has consisted of solvent extraction of the sample, followed by cleanup of the extract through Uquid—Uquid or column chromatography, and finally, concentration through evaporation (285). This complex but necessary series of procedures is time-consuming and is responsible for the high cost of herbicide analyses. The advent of soUd-phase extraction techniques in which the sample is simultaneously cleaned up and concentrated has condensed these steps and thus gready simplified sample preparation (286). 

An ion chromatographic system that included column switching and gradient analysis was used for the deterrnination of cations such as Na", Ca ", Mg ", K", and NH" 4 and anions such as Cf, NO, NO , and in fog water samples (72). Ion-exchange chromatography compares very well with... 

Although simple analytical tests often provide the needed information regarding a water sample, such as the formation and presence of chloroform and other organohaUdes in drinking water, require some very speciali2ed methods of analysis. The separation of trace metals into total and uncomplexed species also requires special sample handling and analysis (12). 

Color. Many water samples have a yellow to brownish-yeUow color which is caused by natural substances, eg, leaves, bark, humus, and peat material. Turbidity in a sample can make the measurement of color uncertain and is usually removed by centrifiigation prior to analysis. The color is usually measured by comparison of the sample with known concentrations of colored solutions. A platinum—cobalt solution is used as the standard, and the unit of color is that produced by 1 mg/L platinum as chloroplatinate ion. The standard is prepared from potassium chloroplatinate (K PtCl ) and cobalt chloride (C0CI26H2O). The sample may also be compared to suitably caUbrated special glass color disks. 

Coimnonly used methods for tlie measurement of pestieides in water samples involve. Solid Phase Exttaetion (SPE) followed by Gas Chromatography or High Performanee Liquid Cliromatography (HPLC) analysis. SPE is a multiple step proeedure and, thus, time eonsuming. 

A powerful tool now employed is that of diode array detection (DAD). This function allows peaks detected by UV to be scanned, and provides a spectral profile for each suspected microcystin. Microcystins have characteristic absorption profiles in the wavelength range 200-300 nm, and these can be used as an indication of identity without the concomitant use of purified microcystin standards for all variants. A HPLC-DAD analytical method has also been devised for measurement of intracellular and extracellular microcystins in water samples containing cyanobacteria. This method involves filtration of the cyanobacteria from the water sample. The cyanobacterial cells present on the filter are extracted with methanol and analysed by HPLC. The filtered water is subjected to solid-phase clean-up using C g cartridges, before elution with methanol and then HPLC analysis. 

---