Environmental analysis herbicides

Membrane extraction is especially effective in discriminating toward macromolecules. In environmental analysis, macro-molecular humic acids are ubiquitous and usually very efficiently removed. Megersa et al. [63] compared SLM and SPE of some triazine herbicides spiked in river water. As is seen from Figure 12.5, the difference is dramatic. Also, there are many examples of how various drugs can be determined in blood plasma and also urine without matrix interferences [25,64]. 

M. Ibanez, J.V. Sancho, O.J. Pozo, F. Hernandez, Use of Q-TOF-MS in environmental analysis Elucidation of transformation products of triazine herbicides in water after UV exposure. Anal. Chem., 76 (2004) 1328. 

It is used in organic synthesis as a methylating agent to methylate acidic compounds such as carboxylic acids and phenols. It is used in trace environmental analysis to methylate chlorophenoxy acid herbicides. 

The considerable and increasing number of appHcations where this interface operated in parallel to theTSP interface was the beginning of a fruitful development in LC-MS analysis. The method in general was reviewed in several papers and was also partly compared to results obtained by other interface types [6, 29, 32, 71]. In the field of environmental analysis, that is, predominantly in the detection, identification and quantification as weU as in the confirmation after UV-DAD [72] of pesticides, herbicides and their biochemical or physicochemical degradation products, PBI-MS was appHed. These results can be found in the Hterature together with a few results on surfactants and dyes. 

I 75.3 LC-MS Interfaces Applied in Environmental Analysis During the Last Decade Pesticides (inciuding herbicides, fungicides etc.)... 

For the absorbance-based detectors, alternative cell geometries have been designed to extend the optical pathlength such as the Z-shaped cells, bubble cells, rectangular cells, and multireflection capillaries. Although manufacturing and manipulation of these special cells can pose a few operational problems, sensitivity enhancement of tenths of fold have been reported. The determination of the herbicide metribuzin and its major conversion products in soil is an example of the use of bubble cells, whereas the UV-detection of derivatized carbonyl compounds in rain is an example of the use of Z-shaped cells in environmental analysis. 

The growing importance of this technique in the field of environmental analysis is emphasized by the appearance of first CE methods that are applicable to routine problems such as the determination of polar volatiles, most semivolatiles, nonvolatiles (e.g., herbicides), inorganic cations, inorganic anions, and natural organic matter (NOM). Most of the compounds determined by CE in different environmental matrices are shown in Table 1. 

See also Elemental Speclatlon Practicalities and Instrumentation. Endocrine Disrupting Chemicals. Environmental Analysis. Geochemistry Soil, Major Inorganic Components Soil, Minor Inorganic Components Soil, Organic, Components. Herbicides. Humic and Fulvic Compounds. Polycyclic Aromatic Hydrocarbons Determination. Surfactants and Detergents. Water Analysis Organic Compounds. 

Biological monitoring techniques such as immunoassays are now available for environmental analysis. These form the basis of low cost, rapid, and highly selective kits for the determination of specific compounds or classes of compounds, such as polyaromatic hydrocarbons, polychlorinated biphenyls, pesticides, herbicides, and insecticides, in food, water, and soil matrices. They are simple to use and are well suited to screening sites for contamination prior to sampling and laboratory analysis. Immunoassays can also be applied to blood and urine samples for assessing the exposure of organisms to contaminants. 

See alsa Chromatography Multidimensional Techniques. Environmental Analysis. Extraction Solid-Phase Extraction. Food and Nutritional Analysis Sample Preparation Contaminants Pesticide Residues. Forensic Sciences Drug Screening in Sport Illicit Drugs. Herbicides. Liquid Chromatography Instrumentation Clinical Applications Food Applications. Mass Spectrometry Peptides and Proteins. Pesticides. Pharmaceutical Analysis Sample Preparation. Proteomics. Sample Handling Automated Sample Preparation. Water Analysis Organic Compounds. 

The analysis of pesticides and herbicides has mainly been done either by GC with selective detectors or by HPLC with ultraviolet (UV) detection. As summarized in Table 1, GC is limited to thermally stable volatile compounds, whereas the HPLC with UV can only detect compounds with chromophores. These limitations of GC and HPLC led to the use of SFC in the analysis of pesticides and herbicides. Among the SFC works in environmental analysis, one-third of the works concerns the analysis of pesticides and herbicides. 

Analysis of environmental behaviors and characteristics of clacyfos showed that it had no negative impact on environment. Therefore, clacyfos would be an environmental-friendly herbicide. 

Reichert, J. Gemikeites, T Winkler, M. Application of HPLC with fluorescence detection to environmental analysis exemplified with the herbicide dalapon. Vom Wasser 1994,82, 37 8. 

Numerous collections of herbicide analysis methods have been pubUshed (276—279). An increased emphasis has been placed on the first step in the environmental sampling process, that of obtaining a representative, uncontaminated sample. If this is to be accompUshed, consideration must be made of such factors as sample size and location (280—283). After the sample has been obtained, it must be stored in such a way as to minimize degradation. This generally consists of refrigeration, possibly preceded by some type of drying (284). 

EPA. 1997e. Methods and guidance for analysis of water. Method 508.1 Determination of chlorinated pesticides, herbicides, and organohalides by liquid-solid extraction and electron capture gas chromatography. U.S. Environmental Protection Agency, Washington, DC. EPA 821-C-97-001. 

Analytical methods for parent chloroacetanilide herbicides in soil typically involve extraction of the soil with solvent, followed by solid-phase extraction (SPE), and analysis by gas chromatography/electron capture detection (GC/ECD) or gas chromatog-raphy/mass spectrometry (GC/MS). Analytical methods for parent chloroacetanilides in water are similarly based on extraction followed by GC with various detection techniques. Many of the water methods, such as the Environmental Protection Agency (EPA) official methods, are multi-residue methods that include other compound classes in addition to chloroacetanilides. While liquid-liquid partitioning was used initially to extract acetanilides from water samples, SPE using... 

Pesticides, including insecticides, herbicides, and fungicides, are widely used in agriculture, and the potential for these residues to accumulate in food has led to concern for human safety. Pesticide residues may enter food animals from environmental sources or from treated or contaminated feeds. Immunoassay development for pesticides has had major impacts for pesticide registrations, analysis of residues in foods, monitoring environmental contamination, determination of occupational exposure, and integration of pest management. 

Automated online SPE LC systems are used extensively for environmental assays. Trays of SPE cartridges and autosampler can be used in the field. Water samples are preconcentrated trays of SPE cartridges loaded with analytes are brought to the laboratory and mounted onto an online SPE LC/ MS/MS system for analysis. Prospekt and Symbiosis systems were used for monitoring herbicides and transformation products (Hogenboom et al. 1998,1999a and b Lopez-Roldan et al. 2004 Kato et al. 2003 Lacorte and Barcelo 1995 Ferrer and Barcelo 1999,2001 Riediker et al. 2002), phenols... 

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