Determination of sulfonylurea herbicides in grains by capillary electrophoresis.

A capillary electrophoresis (CE) method was developed to separate and determine residues of 5 sulfonylurea herbicides in grains (wheat, barley, and corn). This work demonstrated the practicality of using CE for residue analysis of sulfonylureas. The method yielded good recoveries and adequate sensitivities at tolerance levels (0.05-0.1 ppm). The compounds investigated were metsulfuron methyl (Ally), thifensulfuron methyl (Harmony), chlorsulfuron (Glean), rimsulfuron (DPX-E9636), and tribenuron methyl (Express). Acetonitrile extracts of grain samples were partitioned with hexane and then cleaned up with cation exchange solid-phase extraction cartridges. Quantitation was performed by micellar electrokinetic capillary chromatography using a high-sensitivity optical cell. Average recoveries at the 0.05 ppm level ranged from 72.9 to 118.5%. The lower limit of detection was approximately 0.02 ppm, except for rimsulfuron and tribenuron methyl, for which the lower limit of detection was 0.035 ppm. The method was less complicated and showed better sensitivity than current single-analyte liquid chromatographic enforcement methods.

Organochlorine and mercury residues in Swainson's and ferruginous hawk eggs collected in North and South Dakota, 1974-79.

Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury were measured in eggs of Swainson's hawks (Buteo swainsoni) and ferruginous hawks (B. regalis) collected in North and South Dakota during 1974-79. DDE was the most common compound detected in the eggs, but residues were below levels known to have adverse effects on reproduction. Other organochlorine compounds and mercury were found at low levels. Eggs of ferruginous hawks tended to contain more compounds with higher residues than eggs of Swainson's hawks.

Pesticide, PCB, and lead residues and necropsy data for bald eagles from 32 states-1978-81.

In 1978-81, 293 bald eagles (Haliaeetus leucocephalus) from 32 states were necropsied and analyzed for organochlorine pesticides, polychlorinated biphenyls (PCB), and lead residues. DDE was found in all carcasses; PCB, DDD, trans-nonachlor, dieldrin and oxychlordane were next in order of percent frequency of detection. The median levels of DDE and PCB have declined when compared with previous collections. Five specimens contained high levels of dieldrin in their brains which may have contributed to their deaths. Seventeen eagles contained liver lead residues greater than 10 ppm and probably died of lead poisoning. Trauma and shooting are the most common causes of death.

High PCB residues in birds from the Sheboygan River, Wisconsin.

Organochlorine residues were measured in the carcasses and, in some cases, brains and stomach contents of four species of birds collected along the Sheboygan River, Wisconsin during the years 1976 to 1980. Polychlorinated biphenyls (PCBs) were high in all samples and were the contaminants of greatest concern. Carcass residues ranged from 23 to 218 ppm PCBs on a wet weight basis; these are levels associated with reproductive impairment in laboratory studies with some birds. Food items in the stomachs of collected birds contained from 12 to 58 ppm PCBs, indicating a heavy contamination of food sources. The brain of one bird contained 220 ppm PCBs, a level that is not in the lethal range but is very high. Birds feeding in the contaminated portions of the Sheboygan River may have been harmed by high PCB levels.

Acute toxicities of toxaphene and endrin to larvae of seven species of amphibians.

Seven species of amphibian larvae were exposed to toxaphene and endrin in a continuous-flow dosing system to determine differences in sensitivity to the two compounds, EC50 and LC50 estimates varied from those for Rana sphenocephala by no more than one order of magnitude when calculated on the basis of intended concentrations. Removal of pesticides from water by the test animals was significant and it makes interpretation of results difficult. Continuous-flow toxicity tests conflict with the adaptations of amphibian larvae for static water; use of such tests for amphibians requires further evaluation.

Organochlorine residues and mortality of herons.

Since 1966, 72 herons found dead or moribund in the field have been analyzed for organochlorine chemicals. In addition, 36 herons were obtained through systematic collections, and carcasses were analyzed to determine sublethal exposure to organochlorines. Brains of birds found dead or moribund were analyzed to determine whether the birds had died of organochlorine poisoning. Residues of DDE were found most frequently (96 of 105 carcasses analyzed), PCBs were second (detected in 90 carcasses), and dieldrin and TDE (detected in 37 and 35 carcasses, respectively) were about equal as third and fourth most frequent. Endrin, mirex, toxaphene, and HCB were found least often (8, 9, 9, and 9 carcasses, respectively). At least one organochlorine was found in each carcass, except for six heron chicks found dead in a Maryland heronry. DDE and PCBs were present in highest concentrations; they exceeded 100 ppm in two birds each. Organochlorine concentrations were almost always higher in adult herons than in immature birds. All birds that had hazardous or lethal concentrations in the brain were adults, and most were great blue herons (Ardea herodias). Dieldrin was the chemical most often considered responsible for death. Herons died of suspected DDT and dieldrin poisoning years after the chemicals were banned in the United States. More than 20 percent of the herons found dead or moribund had lethal or hazardous concentrations of organochlorines in the brain.

Organochlorine pesticide, PCB, and PBB residues and necropsy data for bald eagles from 29 states--1975-77.

During 1975-77, 168 bald eagles (Haliaeetus leucocephalus) found moribund or dead in 29 states were analyzed for organochlorine pesticides and polychlorinated biphenyls (PCBs); 32 specimens from 13 states were analyzed for polybrominated biphenyls (PBBs). PCBs were present in 166 bald eagle carcasses and DDE was found in 165. TDE and dieldrin were identified in 137 samples, trans-nonachlor in 118, and oxychlordane in 90. Brains of five eagles contained possible lethal levels of dieldrin, and two eagles possibly died of endrin poisoning. Nine eagle livers, analyzed because of suspected lead poisoning, contained high levels of lead. Twenty percent of the eagles died from shooting, the most common cause of death; this cause of death, however, has declined.

Dieldrin-induced mortality in an endangered species, the gray bat (Myotis grisescens).

Brains of juvenile gray bats, Myotis grisescens, found dead beneath maternity roosts in two Missouri caves contained lethal concentrations of dieldrin. One colony appeared to be abnormally small, and more dead bats were found a year after the juvenile bats had been collected. This is the first report to link the field mortality of bats directly to insecticide residues acquired through the food chain.

Gas-liquid chromatographic determination of kepone in field-collected avian tissues and eggs.

A procedure is described for determining Kepone (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta [cd] pentalene-2-one) residues in avian egg, liver, and tissue. Samples were extracted with benzene-isopropanol, and the extract was cleaned up with fuming H2SO4-concentrated H2SO4. Kepone was separated from organochlorine pesticides and polychlorinated biphenyls on a Florisil column and analyzed by electron capture gas-liquid chromatography (GLC). The average recovery from spiked tissues was 86%. The analyses performed on 14 bald eagle carcasses and livers, 3 bald eagle eggs, and 14 osprey eggs show measurable levels which indicate that Kepone accumulates in the tissues of fish-eating birds. Residues were confirmed by GLC-mass spectrometry.

Residues of organochlorine pesticides and polychlorinated biphenyls and autopsy data for bald eagles, 1973-74.

Eighty-six bald eagles found sick or dead during 1973-74 in 24 States were analyzed for organochlorine compounds. DDE was detected in all caracasses; polychlorinated biphenyls (PCB's) were found in all but two. Seventy-five carcasses contained TDE and/or dieldrin. Four eagles had possibly lethal levels of dieldrin in the brain. Bald eagles continue to retain high residue levels of organochlorine pollutants. Illegal shooting remained the most common cause of death but accounted for a smaller percentage of the mortalities than in the two previous biennial collections.

Residues of organochlorine pesticides and polychlorinated biphenyls and autopsy data for bald eagles, 1971-72.

Thirty-seven bald eagles found sick or dead in 18 States during 1971-72 were analyzed for organochlorine pesticides and polychlorinated biphenyls (PCB's). DDE and PCB's were detected in all bald eagle carcasses; 30 carcasses contained DDD and 28 contained dieldrin. Four eagles contained possibly lethal levels of dieldrin and nine eagles had been poisoned by thallium. Autopsies revealed that illegal shooting was the most common cause of mortality. Since 1964 when data were first collected, 8 of the 17 eagles obtained from Maryland, Virginia, South Carolina, and Florida possibly died from dieldrin poisoning; all four specimens from Maryland and Virginia were from the Chesapeake Bay Tidewater area.