Ma. J. González

Solid-phase microextraction method for the determination of atrazine and four organophosphorus pesticides in soil samples by gas chromatography

A simple and rapid solid-phase microextraction (SPME) based method is presented for the simultaneous determination of atrazine and four organophosphorus (i.e. parathion-methyl, chlorpyriphos, methidathion and carbophenothion) in soils. After optimisation of the different experimental variables affecting the SPME of the target compounds from aqueous solutions by using an experimental design, a consensus strategy was adopted which allowed the use of the SPME method developed for the simultaneous screening of all the analytes selected. The complete analytical procedure finally proposed consisted of a 15-min ultrasonic extraction of the target compounds from a 0.5-g soil sample with 5 ml of methanol and the dilution of this extract to up 10% methanol followed by the addition of NaCl to a final concentration of 10% (w/v). The analytes in this aqueous extract were preconcentrated for 30 min in the SPME fiber and subsequently desorbed by heating of the fiber at 260 degrees C for 5 min in the gas chromatograph injection port. Final determination was carried out with an electron-capture detector. The recoveries of the pesticides studied in soils ranged from 72 to 123%, except for atrazine, and the SDs were below 16%. The feasibility of the procedure finally proposed for the screening of the endogenous pesticides irrespective of the properties of the soil selected has been shown.

Determination of polychlorinated biphenyls in small-size serum samples by solid-phase extraction followed by gas chromatography with micro-electron-capture detection.

An new method for the determination of polychlorinated biphenyls (PCBs) in serum samples of up to 1 ml has been developed. The procedure consisted in the solid-phase extraction (SPE) of the analytes on an Oasis cartridge and the subsequent on-line elimination of the fat by directly dropping of the eluate from the SPE cartridge on a multilayer column placed below the cartridge. This configuration allowed minimising of the sample manipulation as well as the time, solvent and sorbent consumption (i.e. complete sample preparation can be accomplished in about 1 h with only 3 ml of toluene and 300 mg of silica). The SPE plus clean-up method developed showed a satisfactory performance for the analysis of PCBs in rat serum samples providing similar recoveries (i.e. range 73-128% for most of the congeners selected) at the different spiking levels investigated (1.25, 0.50 and 0.25 ng/ml). Detection limits using a microelectron capture detector were in the range 0.01-0.30 ng/ml of serum and the relative standard deviations of the complete method better than 18% irrespective of the PCB concentration. The validated method has been applied to the evaluation for the first time of the PCB levels in serum samples of up to 1 ml from individuals of an Egyptian Vulture colony in Spain.

Organochlorine and heavy metal residues in Falconiforme and Ciconiforme eggs (Spain)

Over the last three decades the biosphere has been contaminated almost universally by persistent pollutants of agricultural and industrial origin. Organochlorine pesticides and polychlorinated biphenyls have been documented to have adverse effects of the reproduction and survival of wild birds. Also, environmental contamination from heavy metals has been shown to be a threat to the survival and reproduction of certain birds. The hazard to Falconiforme and Ciconiforme birds is high because a) they are sensitive to eggshell thinning b) they are high in the food chain (Peakall 1975). The present paper reports the levels of organochlorine compounds and heavy metals in 69 eggs of five species of the avian Falconiforme order and two species of the avian Ciconiforme order collected at DoSana National Park and Castile Plateau (Spain). Objectives of this study are (i) to determine the levels of organochlorine pollutants and heavy metals in eggs of Falconiforme and Ciconiforme birds of Spain; (2) to evaluate the impact of the contaminants detected on reproductive potential; (3) to evaluate regional patterns of residues. MATERIALS AND NETHODS Sixty-nine infertile bird eggs were gathered at DoEana National Park and Castile Plateau in 1985 and 1986 breeding season. The Do~ana National Park, an area of 50,720 ha, is located in the south-southwest of the Iberian Peninsula. The Dofiana National Park, which is also a Scientific Reservation of the Biosphere of UNESCO, and area included in the International Agreement of Ramsar for the protection of wet areas, is of the utmost importance for sedentary birds living there. It is also important for birds migrating between Europe and Africa. The Castile Plateau, located in the centre of the Iberian Peninsula, constitute one important breeding habitat of birds in Spain (Figure i).

Suitability of several carbon sorbents for the fractionation of various sub-groups of toxic polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans.

Feasibility of several sorbents, Amoco PX-21, Carbosphere, Carbopack B and C and 2-(1-pyrenyl) ethyldimethylsilylated silica gel (PYE), for the fractionation of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and furans was investigated. Selection was based on their suitability for quantitative isolation of the target compounds with special attention for the most toxic mono- and non-ortho-CBs to prevent coelution with other congeners during the final determination by gas chromatography. Cost-effectiveness in terms of solvent and time consumption as well as feasibility for routine analysis and automation were considered additional merits of the methods compared. Final evaluation of the procedures providing the best results was done by comparison of the results obtained from the analysis of real-life samples. The results showed that, among the sorbents tested, Carbopack B and PYE were the most suitable for routine analysis. In particular, these sorbents allowed a more reliable determination of the toxic congeners and, consequently, of the toxic equivalents of 2,3,7,8-tetrachlorodibenzo-p-dioxin content in environmental samples.

Organochlorine and metal pollution in aquatic organisms sampled in the Doñana National Park during the period 1983–1986

The study area, Donana National Park, is located in the South South-West of Spain, and this is one of the most important reservation of Europe. Samples of aquatic organism were obtained from the principal waterway of Donana National Park to determine the degree of organochlorine and metal contamination of this environment. The sampling was carried out during the period 1983-1986 in order to collect six aquatic species in four sites along the Brazo de la Torre. An agricultural area in the North-West side of the Park and a working mine at about 40 km from its northern boundary were considered as the likely main polluting sources of organochlorine pesticides, PCBs, and heavy metals respectively. The aquatic organism species chosen for analysis were: American crayfish (Procambarus clarckii), carp (Cyprinus carpio), barbel (Barbus barbus), grey mullet (Mugil capito), eel (Anguilla anguilla), and frog (Rana perezi).

Residues of organochlorine chemicals and concentrations of heavy metals in ciconiforme eggs in relation to diet and habitat

Abstract Residues of organochlorine pollutants and heavy metals were determined in 50 aquatic organisms of five species, 31 eggs of four species of wading birds, water, and sediment collected at Donana National Park, (Spain) during the nesting season 1983 and 1984. The species analyzed were the Spanish frog (Rana perezi), the American crayfish (Procambarus clarkii), the grey mullet (Mugil capito), the common carp (Cyprinus carpio), the European eel (Anguilla anguilla), the purple heron (Ardea purpurea), the grey heron (Ardea cinerea), the white stork (Ciconia ciconia), and the little egret (Egretta garzetta). DDE and PCBs were detected in all samples. ?,‐HCH, ?‐HCH, TDE, DDT,dieldrin, and heptachlor epoxide were also detected, but less frequently. Aldrin, heptachlor, and dichlorobenzophenone were not detected. Hg, Cd, Pb, Cu, and Zn were detected in all samples. The levels of contaminants investigated are generally below the levels known to cause direct effects on survival or reproduction. Biomagnificatio...

Presence and biomagnification of organochlorine pollutants and heavy metals in mammals of Donana National Park (Spain), 1982-1983

The existence of 11 organochlorine compounds and five heavy metals in the liver and muscle of 57 members of 10 species of mammals, all from Doñana National Park (Spain), has been investigated. Five organochlorine compounds have been found and the five heavy metals were present in the samples. The biomagnification of organochlorines is shown. The detected concentrations for each trophic rank seem not to influence unfavourably on the population stability of the species. The rabbit is proposed as a monitor species for future studies in pollution at Doñana National Park.

Lindane pollution near an industrial source in northeast Spain.

Since DDT has been legally restricted for use in many countries, lindane, the gamma isomer of hexachlorocyclohexane, ({delta}-HCH), has become important as a substitute for DDT. Lindane is degraded poorly in the environment: it is hydrolyzed poorly and biodegrades slowly. Lindane is relatively immobile in soil. The town of Sabinanigo, located in northeast of the Iberian Peninsula, is host to one of only two factories in western Europe that manufacture lindane. HCH waste is being dumped near Sabinanigo by the chemical company Inquinosa. The purpose of this investigation are: (1) to determine the levels of HCH isomers in water, soil, vegetation, and invertebrates samples in five places of the Gallego river; (2) to evaluate biological accumulation of pollutant studied within the food webs; (3) to find out if the residue levels exceeded the limits recommended of HCH in water.

Residues of organochlorine pesticides, polychlorinated biphenyls and heavy metals in the eggs of predatory birds from Doñana National Park (Spain), 1980–1983

Abstract Organochlorine pesticides and heavy metal residues were determined in 54 eggs of five species of predatory birds collected at Donana National Park (Spain) during the nesting season between 1980 and 1983. The species analyzed were the imperial eagle (Aquila heliaca), the red kite (Milvus milvus), the black kite (Milvus migrans), the hobby (Falco subbuteo) and the booted eagle (Hieraetus pennatus). DDE, DDT and PCBs were detected in all samples. α‐HCH, α‐HCH, aldrin, dieldrin, heptachlor, heptachlor epoxide, TDE and dichlorobenzophenone were also detected but less frequently. The DDE content of eggs decreased in the period between 1972/1976 and 1980/1983, but the PCBs contents were stable. The declines are attributed to the restrictions on the use of DDT in most countries. Mercury, lead, cadmium, copper and zinc were detected in all samples. The levels of organochlorine pesticides, PCBs and heavy metals in these Falconiforme eggs are generally below the levels known to cause direct effects on survi...

Total PCBs and PCB congeners in spanish imperial eagle eggs

The Spanish Imperial Eagle Aquila (heliaca) adalberti is the only directly endangered bird of prey in Europe. Lowered reproductive success in numerous bird species has been associated with eggshell thinning and reduced production caused by DDE, the most common organochlorine residue found in wild birds. Polychlorinated biphenyls (PCBs) are usually the second most common organochlorine pollutant found in wild birds. Research to evaluate the incidence of organochlorine pollutants in the Spanish Imperial Eagle has been previously conducted. The authors have now determined the levels of total PCBs and selected PCB congeners in 34 eggs of Spanish Imperial Eagle collected at Donana National Park, Castile Plateau and Nature Park of Monfrague, since this has considerable significance when attempts are made to correlate the embryonic mortality of avian wildlife with PCB residue levels.