Damià Barceló

Bio: Damià Barceló is an academic researcher from United States Geological Survey. The author has contributed to research in topics: Medicine & Atmospheric-pressure chemical ionization. The author has an hindex of 11, co-authored 14 publications receiving 1287 citations. Previous affiliations of Damià Barceló include École Normale Supérieure & University of Mainz.

Trace Determination of Pesticides and their Degradation Products in Water

Abstract: Pesticides and their Degradation Products: Characteristics, Usage and Environmental Behaviour. Introduction. Chemical classes and physico-chemical properties of pesticides. Environmental relevance in the aquatic environment. Degradation of pesticides in the aquatic environment. Toxicity and ecotoxicity. Conclusions. References. Quality Assurance Issues: Sampling, Storage and Interlaboratory Studies. Sampling. Storage. Interlaboratory performance studies. References. Chromatographic and Related Techniques for the Analysis and Detection of Pesticides. Introduction. Gas chromatography. Liquid chromatography. Thin layer chromatography. Capillary electrophoresis. Mass spectrometric methods. Conclusions. References. Sample Handling Techniques (Extraction and Clean-up of Samples). Introduction. Extraction and concentration procedures. Clean-up procedures. Conclusion and further developments. References. On-Line Sample Handling Strategies. Introduction. On-line techniques with separation by liquid chromatography. On-line techniques with separation by gas chromatography. On-line solid-phase extraction, supercritical fluid extraction, and supercritical chromatography. Conclusion and further trends. References. Immunochemical Methods and Biosensors. Introduction. Immunoassays. Immunochemical sample preparation methods. Biosensors. Conclusions and perspectives.

Choosing between atmospheric pressure chemical ionization and electrospray ionization interfaces for the HPLC/MS analysis of pesticides.

Abstract: An evaluation of over 75 pesticides by high-performance liquid chromatography/mass spectrometry (HPLC/MS) clearly shows that different classes of pesticides are more sensitive using either atmospheric pressure chemical ionization (APCI) or electrospray ionization (ESI) For example, neutral and basic pesticides (phenylureas, triazines) are more sensitive using APCI (especially positive ion) While cationic and anionic herbicides (bipyridylium ions, sulfonic acids) are more sensitive using ESI (especially negative ion) These data are expressed graphically in a figure called an ionization-continuum diagram, which shows that protonation in the gas phase (proton affinity) and polarity in solution, expressed as proton addition or subtraction (pKa), is useful in selecting APCI or ESI Furthermore, sodium adduct formation commonly occurs using positive ion ESI but not using positive ion APCI, which reflects the different mechanisms of ionization and strengthens the usefulness of the ionization-continuum diagram

Selective trace enrichment of chlorotriazine pesticides from natural waters and sediment samples using terbuthylazine molecularly imprinted polymers

Abstract: Two molecularly imprinted polymers were synthesized using either dichloromethane or toluene as the porogen and terbuthylazine as the template and were used as solid-phase extraction cartridges for the enrichment of six chlorotriazines (deisopropylatrazine, deethylatrazine, simazine, atrazine, propazine, and terbuthylazine) in natural water and sediment samples. The extracted samples were analyzed by liquid chromatography/diode array detection (LC/DAD). Several washing solvents, as well as different volumes, were tested for their ability to remove the matrix components nonspecifically adsorbed on the sorbents. This cleanup step was shown to be of prime importance to the successful extraction of the pesticides from the aqueous samples. The optimal analytical conditions were obtained when the MIP imprinted using dichloromethane was the sorbent, 2 mL of dichloromethane was used in the washing step, and the preconcentrated analytes were eluted with 8 mL of methanol. The recoveries were higher than 80% for all ...

Evaluation of a multidimensional solid-phase extraction platform for highly selective on-line cleanup and high-throughput LC-MS analysis of triazines in river water samples using molecularly imprinted polymers.

Abstract: A novel highly selective sample cleanup procedure based on the use of molecularly imprinted polymers (MIPs) as solid-phase extraction materials has been evaluated with respect to its applicability and routine use in environmental analysis. The method comprises the combination of a restricted access material (RAM) and a MIP allowing a selective sample preparation to be achieved in the on-line mode. This combination is called the size-selective sample separation and solvent switch (six-SPE). The RAM column combines size exclusion and adsorption chromatography, reducing the concentration of matrix molecules by a cutoff of 15 kDa. The MIP column selectively retains the triazine analytes whereas the residual matrix is not retained and separated completely. Thus, the automated RAM-MIP is capable of excluding all matrix and nontarget compounds. The cleaned and enriched extract is subsequently eluted to an HPLC column and analyzed by LC−MS. A complete on-line analysis cycle including multidimensional solid-phase ...

Degradation of Chloroacetanilide Herbicides: The Prevalence of Sulfonic and Oxanilic Acid Metabolites in Iowa Groundwaters and Surface Waters

Abstract: Water samples were collected from 88 municipal wells throughout Iowa during the summer and were collected monthly at 12 stream sites in eastern Iowa from March to December 1996 to study the occurrence of the sulfonic and oxanilic metabolites of acetochlor, alachlor, and metolachlor. The sulfonic and oxanilic metabolites were present in almost 75% of the groundwater samples and were generally present from 3 to 45 times more frequently than their parent compounds. In groundwater, the median value of the summed concentrations of acetochlor, alachlor, and metolachlor was less than 0.05 μg/L, and the median value of the summed concentrations of the six metabolites was 1.2 μg/L. All surface water samples contained at least one detectable metabolite compound. Individual metabolites were detected from 2 to over 100 times more frequently than the parent compounds. In surface water, the median value of the summed concentrations of the three parent compounds was 0.13 μg/L, and the median value of the summed concentr...

Impact of pesticides use in agriculture: their benefits and hazards.

Abstract: The term pesticide covers a wide range of compounds including insecticides, fungicides, herbicides, rodenticides, molluscicides, nematicides, plant growth regulators and others. Among these, organochlorine (OC) insecticides, used successfully in controlling a number of diseases, such as malaria and typhus, were banned or restricted after the 1960s in most of the technologically advanced countries. The introduction of other synthetic insecticides – organophosphate (OP) insecticides in the 1960s, carbamates in 1970s and pyrethroids in 1980s and the introduction of herbicides and fungicides in the 1970s–1980s contributed greatly to pest control and agricultural output. Ideally a pesticide must be lethal to the targeted pests, but not to non-target species, including man. Unfortunately, this is not the case, so the controversy of use and abuse of pesticides has surfaced. The rampant use of these chemicals, under the adage, “if little is good, a lot more will be better” has played havoc with human and other life forms. Production and usage of pesticides in India The production of pesticides started in India in 1952 with the establishment of a plant for the production of BHC near Calcutta, and India is now the second largest manufacturer of pesticides in Asia after China and ranks twelfth globally (Mathur, 1999). There has been a steady growth in the production of technical grade pesticides in India, from 5,000 metric tons in 1958 to 102,240 metric tons in 1998. In 1996–97 the demand for pesticides in terms of value was estimated to be around Rs. 22 billion (USD 0.5 billion), which is about 2% of the total world market. The pattern of pesticide usage in India is different from that for the world in general. As can be seen in Figure 1, in India 76% of the pesticide used is insecticide, as against 44% globally (Mathur, 1999). The use of herbicides and fungicides is correspondingly less heavy. The main use of pesticides in India is for cotton crops (45%), followed by paddy and wheat. Figure 1 Consumption pattern of pesticides. Benefits of pesticides The primary benefits are the consequences of the pesticides' effects – the direct gains expected from their use. For example the effect of killing caterpillars feeding on the crop brings the primary benefit of higher yields and better quality of cabbage. The three main effects result in 26 primary benefits ranging from protection of recreational turf to saved human lives. The secondary benefits are the less immediate or less obvious benefits that result from the primary benefits. They may be subtle, less intuitively obvious, or of longer term. It follows that for secondary benefits it is therefore more difficult to establish cause and effect, but nevertheless they can be powerful justifications for pesticide use. For example the higher cabbage yield might bring additional revenue that could be put towards children's education or medical care, leading to a healthier, better educated population. There are various secondary benefits identified, ranging from fitter people to conserved biodiversity. Improving productivity Tremendous benefits have been derived from the use of pesticides in forestry, public health and the domestic sphere – and, of course, in agriculture, a sector upon which the Indian economy is largely dependent. Food grain production, which stood at a mere 50 million tons in 1948–49, had increased almost fourfold to 198 million tons by the end of 1996–97 from an estimated 169 million hectares of permanently cropped land. This result has been achieved by the use of high-yield varieties of seeds, advanced irrigation technologies and agricultural chemicals (Employment Information: Indian Labour Statistics, 1994). Similarly outputs and productivity have increased dramatically in most countries, for example wheat yields in the United Kingdom, corn yields in the USA. Increases in productivity have been due to several factors including use of fertiliser, better varieties and use of machinery. Pesticides have been an integral part of the process by reducing losses from the weeds, diseases and insect pests that can markedly reduce the amount of harvestable produce. Warren (1998) also drew attention to the spectacular increases in crop yields in the United States in the twentieth century. Webster et al. (1999) stated that “considerable economic losses” would be suffered without pesticide use and quantified the significant increases in yield and economic margin that result from pesticide use. Moreover, in the environment most pesticides undergo photochemical transformation to produce metabolites which are relatively non-toxic to both human beings and the environment (Kole et al., 1999).

Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003

Abstract: Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003