Reverse phase high performance liquid chromatographic determination of Baygon in water

Abstract

A simple analytical procedure for determination of Baygon in water is described. The Baygon residues are extracted on a C₁₈ SEP‐PAK cartridge and subsequently analyzed by reverse phase high performance liquid chromatography using ultraviolet detection at 272 nm. Water samples spiked with Baygon are found to give greater than 90 percent recoveries.

Concentration levels as low as 20 ppb can be easily detected by this method.     

A preliminary examination of the translocation of microencapsulated cyfluthrin following applications to the perimeter of residential dwellings

Abstract

Methods have been developed to monitor the translocation of microencapsulated cyfluthrin following perimeter applications to residential dwellings. A pilot study was implemented to determine both the potential for application spray to drift away from dwellings and the intrusion of residues into homes following perimeter treatments. Residential monitoring included measuring spray drift using cellulose filter paper and the collection of soil samples from within the spray zone. In addition, interior air was monitored using fiberglass filter paper as a sorbent medium and cotton ball swabs were used to collect surface wipes.

Fortification of matrixes resulted in recoveries of >90%. Spray drift was highest at the point of application and declined to low but measurable levels 9.1m from the foundations of dwellings. Soil residues declined to low, but measurable levels by 45 days post‐application. No cyfluthrin was measured from indoor air; however, some interior surfaces had detectable levels of cyfluthrin until three days post‐application.

Findings indicate that spray drift resulting from perimeter applications might contaminate non‐target surfaces outside the spray zone. Soil borne residues may serve as persistent sources for human exposure and potentially intrude into dwellings through the activities of occupants and pets. Residues do not appreciably translocate through air and consequently inhalation is not a likely route for human exposure. Surface residues detected indoors suggest that the physical movement of residues from the exterior to the interior might be a viable route of movement of residues following this type of application.     

Levels of Persistent Organochlorine Residues in Eggs of Greater Flamingos from the Guadalquivir Marshes (Doñana), Spain

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) residue levels were determined in 53 unhatched eggs from greater roseus flamingos (Phoenicopterus ruber). Eggs were collected in 1996 from the National Park of Doñana (Guadalquivir marshes, Southwest Spain), immediately after one breeding colony abandoned the nesting site due to predator attacks. The main metabolite of p,p′-DDT, p,p′-DDE, was the OCP residue found at higher concentrations, with a geometric mean of 721 ng/g wet weight. Residues of other pesticides, including some hexachlorocyclohexane isomers, hexachlorobenzene, aldrin, heptachlor, and heptachlor-epoxide, were detected at much lower concentrations. The sum of PCBs was 528 ng/g, with PCB congeners #187 and #153 being the most prominent in eggs. The pattern observed in these compounds of industrial origin corresponded more to Aroclor 1260 than to any other commercial mixture. Levels of organochlorine residues indicate a medium degree of exposure, and they are not considered of any concern for the flamingo population. In particular, neither p,p′-DDE nor PCB levels were found to be correlated with the eggshell thickness.     

Organochlorine residues in finfish from Maryland waters 1976–1980

Abstract

Organochlorine pesticide and herbicide levels were monitored in samples of a variety of edible finfish harvested from the Maryland section of the Chesapeake Bay and its tributaries over a five‐year period (1976–80). Qualitative and quantitative information was obtained for the various polychlorinated biphenyls (PCB's), heptachlor, α‐BHC, chlordane, DDD, DDE, DDT, dieldrin, endrin, heptachlor‐epoxide, lindane, mirex, methoxychlor, aldrin, toxaphene, hexachlorobenzene, kepone and dacthal.

In addition to analyses of the flesh of the animals, organochlorine residue levels were determined in roe or gonad tissue of several samples. Striped bass, white perch and yellow perch samples showed significantly higher concentrations of certain of these substances in roe or gonad tissue, especially PCB's, chlordane, DDD and dieldrin. Significantly higher levels of six organochlorine residues were found in the gonad tissue of striped bass; however, similar studies on gonad tissue of American Shad, harvested from the same region, show no such enhancement. Rather, the reverse is true; levels of certain organochlorine residues are higher in flesh tissue.

All mean values, and virtually all individual values of organochlorine concentrations in the edible portion of the fish were within the U.S. Food and Drug Administration guideline, where such guidelines have been established.     

Determination of organochlorine and organophosphorus pesticide residues in low moisture,nonfatty products using a solid phase extraction cleanup and gas chromatography

Abstract

A multiresidue solid‐phase extraction (SPE) method for the isolation and subsequent gas Chromatographie determination of organochlorine and organophosphorus pesticide residues in low‐moisture, nonfatty products is described. Residues are extracted from samples with an acetonitrile/water mixture. Cleanup of the extract is performed using graphitized carbon black and anion exchange SPE columns, and analysis is performed by gas chromatography with Hall electrolytic conductivity and flame photometric detection. Recovery data was obtained by fortifying corn, oats and wheat with pesticides. The average recoveries were 79–123% for eight organochlorine and 51–122% for 28 organophosphorus pesticide residues. The limit of quantitation for chlorpyriphos was 0.05 ppm using the Hall electrolytic conductivity detector and <0.005 ppm using the flame photometric detector.     

Pesticide decontamination from fabric by laundering and simulated weathering1

Abstract

This laboratory study investigated the effectiveness of selected detergents and the phenomenon of simulated environmental conditions (weathering) on the removal of a commercial‐grade mixture of parathion and methyl parathion from a three‐layer laminated fabric. The weathering treatment consisted of exposure and non‐exposure to simulated environmental conditions of heat, light, and humidity. Contaminated fabric samples were laundered in one of three detergents containing an anionic, a nonionic, and a combined anionic and nonionic surfactant. The test fabric, a three‐layer fabric containing an impermeable microporous film laminated between two layers of nylon, was pipette‐contaminated with 400 microliters of field strength pesticide solution and allowed to dry. Half of the contaminated samples were weathered in an Atlas Fade‐Ometer. All of the contaminated samples were subsequently laundered in a Launder‐Ometer. Percent of pesticide residue was determined by gas chromatography. Weathering did significantly reduce both parathion and methyl parathion residues remaining in the test fabric. No statistically significant difference was found among the three detergents. High amounts of both parathion and methyl parathion remained in the test fabric after weathering and laundry treatments. Before the test fabric can be recommended for use in protective garments further research is needed to develop more effective decontamination procedures.     

Diflubenzuron residue and persistence on an oak forest after aerial application

Abstract

A twenty hectare forest block in central Pennsylvania was aerially sprayed with diflubenzuron (Dimilin 25W®) at the dose of 33.23g A.I./ha in 9.4 litres/ha. Leaf samples were collected from the upper and lower canopies of 27 oaks and understory within this block on the day of spray, May 29, 1991. Canopy leaves were also collected on May 31, June 10, July 29 and September 26, 1991.

Recovery of diflubenzuron residues on fortified canopy‐leaf and litter‐leaf samples using analytical techniques employed in this study averaged 87.4% (SE = 7.5%) and 66.2% (SE = 8.2%), respectively.

On the day of spray, diflubenzuron residues on the upper canopy, lower canopy and understory averaged 81.18, 39.65 and 8.35 ng/cm², respectively. Diflubenzuron residues on canopy‐leaf samples collected 2, 12, 61 and 120 days post‐spray averaged 14.83 (SE = 10.19), 16.75 (SE = 9.95), 12.84 (SE = 8.25) and 11.20 (SE = 7.52) ng/cm², respectively. Diflubenzuron residues on litter‐leaf samples collected after leaf senescence ‐ 169 and 323 days post spray contained measurable amounts of diflubenzuron in 51 and 59% of the samples, respectively. Of the samples with measurable amounts of diflubenzuron, residues averaged 1.36 (SE = 2.44) and 0.65 ng/cm² (SE = 0.73) respectively.     

Simultaneous determination of fenitrothion and aminocarb in blueberry foliage and fruits: Application to the analysis of residues in field samples

Abstract

Samples of blueberry foliage and fruits were collected from spray blocks in Ontario after aerial application of fenitrothion and aminocarb at dosage rates of 210 g active ingredient (AI)/ha and 70 g AI/ha respectively. Residues were extracted from the samples by homogenizing with ethyl acetate, cleaned up by microcolumn chromatography using alumina as adsorbent, and analyzed by GLC‐AFID with a glass column packed with 1.5% OV‐17 and 1.95% OV‐210 on 80–100 mesh Chromosorb W‐HP. Average recoveries for fenitrothion and aminocarb from foliage at three fortification levels (1.0, 0.10 and 0.01 ppm) were respectively 99 and 96%. The corresponding values for the fruits were 99 and 95%. Foliage samples collected 1 h post‐spray contained on average 1.13 ppm of fe‐nitrothion and 1.14 ppm of aminocarb. However, residue levels reached below the detection limit (<0.01 ppm) in foliage collected 15 d after treatment. In addition, the fruit samples collected after 15 d post‐spray contained extremely low levels (0.03 ppm for fenitrothion and 0.02 ppm for aminocarb) of residues, and were barely above the detection limit.     

Biodegradation of fatty acylamino acids by fusarium culmorum

Abstract

Biodegradation of the fatty acylamino acids by Fusarium culmorum, measured in terms of the release of radioactive aspartate and lysine, occurred maximally at pH 6.5 and pH 7.0, respectively in 10 day cultures. Thirty‐six percent and twenty‐four percent of the total radioactivity recovered were in released aspartate and lysine, respectivley at 30°C. Twenty degrees (C) was the minimum temperature for biodegradation of these compounds by F. culmorum. Greater degradation was observed at 15°C and 30°C. The data suggest the activity of hydrolytic isoenzymes, with optima at different pH's and temperatures, operating in the biodegradation process.     

Monitoring of pesticide residues in a cotton crop soil

Abstract

This paper reports on the residues of methyl parathion (O,O‐dimethyl O‐4‐nitrophenyl phosphorothioate), trifluralin (α, α, α‐trifluoro‐2, 6‐dinitro‐N, N‐dipropyl‐p‐toluidine), endosulfan [(1, 4, 5, 6, 7, 7‐hexachloro‐8, 9, 10‐trinorborn‐5‐en‐2, 3‐ylenebismethylene) sulfite] and dimethoate (O, O‐dimethyl S‐methylcarbamoylmethyl phosphorodithioate) in a cotton crop soil. Soil samples (0–15 cm) were collected at different periods from the cotton crop farm and subjected to Soxhlet extraction. The extracted material was analysed after clean‐up by a HP5890 II gas Chromatograph equipped with a ⁶³Ni electron‐capture detector (ECD‐⁶³Ni) and fitted with a 25m x 0,2mm i.d. fused silica capillary column [Ultra‐2 (5% phenylmethyl polysiloxane)]. The recoveries of the pesticide residues from the spiked control soil were determined after Soxhlet extraction and C₁₈ cartridges clean‐up by using radiotracer techniques with the corresponding ¹⁴C‐pesticides. The results show that in the cotton crop soil the pesticide residues under study were present in the range of 0.1 to 0.4 mg ? kg^‐1. Endosulfan was found to be rapidly degraded in the soil and formed a sulfate metabolite.     

The relationship between persistent organic pollutants in maternal and neonatal tissues and immune responses to allergens: A novel exploratory study

BACKGROUND: Modern persistent organic pollutants (POPs) contamination are logical candidates in the investigation of the, as yet, unexplained association between allergic disease and progressive industrialisation. POPs have been detected in human cord blood, placental tissues and breast milk, and the reported association between cord blood IgE levels and cord/placental POP levels has raised concerns about potential immunological effects in early life. METHODS: The initial aim of this study was to determine if POPs were detectable in maternal blood, cord blood, placental tissues, adipose tissue and breast milk samples from randomly selected Western Australian women (n = 31), where allergic disease is epidemic. Gas chromatography was used to detect polychlorinated biphenyl compounds [PCBs] (as Aroclor 1232, 1254, 1260) and organochlorine (OC) pesticides, including p,p'-DDT, p,p'-DDE, hexachlorobenzene (HCB), lindane, heptachlor epoxide, dieldrin and chlordane. Secondly, we assessed the relationship between POP levels detected in vivo and maternal and neonatal responses (cytokine and lymphoproliferation) to allergens and mitogens. RESULTS: Low level POP contamination was detected in adipose tissue and breast milk (but not in cord blood, maternal blood or placental tissues). The most ubiquitous compound found in over 90% of adipose tissues samples was a OC metabolite of DDT, p,p'-DDE (median 0.07 mg/kg; interquartile range [IQR] 0.05-0.12). However, the majority of other OC compounds were not detectable and PCB were not detectable in any samples. The three main residues detected in breast milk were p,p'-DDE (0.003 mg/l; 0.001-0.009), dieldrin (0.001 mg/l; 0.001-0.046) and HCB (0.001 mg/l; 0.001-0.001). These levels are significantly lower than reported over 20 years ago. There were no consistent relationships between POP levels in vivo and maternal or infant responses, with the exception of a significant inverse association (Spearman rank correlation: r = -0.406, p = 0.049) between maternal adipose tissue levels of OC p,p'-DDE and maternal T helper cell Type 1 interferon [IFN] gamma to mitogens. CONCLUSION: This study provides the first evidence (in Australia) since the early 1990's that adipose OC levels have continued to fall. The negligible levels in this randomly selected group are significantly lower than those previously recorded, suggesting that POP contamination (at biologically relevant levels) is not likely to be a major contributing factor in the increasing rates of allergy in Western Australia. However, the relationship between Th1 immune function and OC contamination is consistent with other reports and is worth investigating as a relevant factor in populations where OC contamination is greater.     

Transfer assessment of carbendazim residues from rapeseed to oil production determined by HPLC–MS/MS

Abstract

It is crucial to develop practical procedures for the control and reduction of pesticide residues in oil productions from farm to dining table. In this study, the dissipation behaviors of typical fungicide from rapeseed to oil production were studied to reveal relationship among spraying stage, application dosage, household oil processing stage, and pesticide residues. In the field trials, rape plants were sprayed with carbendazim at three different dosages during flowering period. Transfer assessment of carbendazim residues from rapeseed to oil production during household oil processing via different press techniques was determined using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS). The recoveries of carbendazim in rapeseed samples, meals after squeezing samples, and rapeseed oil samples ranged from 82.5% to 93.6% with relative standard deviations (RSDs) ＜5.2%. The validation results illustrated that the methods were reliable and sensitive. The average processing factor (PF) during household oil processing via hot press technique and cold press technique was 0.15 and 0.51, respectively. This study demonstrated that household oil processing could significantly reduce the pesticide residues, especially by hot press technique.     

The role of toxicology in the evaluation of new agrochemicals

Abstract

The use of agrochemicals like crop protecting agents, veterinary disinfectants, and wood preservatives may result in (un)intentional exposure of the environment, animals and man. This paper deals with current testing strategies to assess the potential health risks for humans exposed to these chemicals during production or application or via consumption of foods containing pesticide residues.

Principles and procedures for safety assessment of pesticide residues in food as developed by WHO/FAO are described. Different types of toxicity studies in mammalian test animal species are discussed and a strategy is outlined in order to characterize the toxicity profile of a compound and the relationship between applied doses and adverse effects. Safety testing of agrochemicals should be carried out in relation to its intended use, and in particular attention will be paid to toxicity testing of residues of pesticides in food. Extrapolation of results from animal studies to humans and the use of safety factors is discussed.

Besides the use of animal protocol studies for safety testing of agrochemicals, the potential use of in‐vitro models derived from organs and tissues of animals is discussed. Data on the in‐vitro metabolism of thiabendazole, aldicarb and alachlor are discussed in order to demonstrate that such data may complement or partly substitute whole animal experimentation.

Principles and procedures for safety testing of residues of agrochemicals in food as applied during the last three decades, constitute a ‘safety‐first’ approach, providing sufficient safety margins for the consumer of foods which may contain low levels of residues of agrochemicals.     

Occurrence of pesticides and polychlorinated biphenyls in water of the Nile river at the estuaries of Rosetta and Damiatta branches,north of delta,Egypt

Abstract

A study was conducted from summer 1995 to summer 1997 to assess the seasonal occurrence of pesticide residues and other organic contaminants, polychlorinated biphenyls (PCBs), in water at the estuaries of Rosetta and Damiatta branches of the Nile river. The results indicated that organochlorine compounds (OCs) including HCB, lindane, p,p‘‐DDE, p,p‘DDD, p,p‘‐DDT, aroclor 1254 and aroclor 1260 were present in all the water samples at concentration levels ranging between 0.195–0.240, 0.286–0.352, 0.035–0.067, 0.019–0.033, 0.024–0.031, 0.390–0.70 and 0.166–0.330 μg/l, respectively. The levels of these compounds were higher in water of Damiatta branch than those found in water of Rosetta branch. Aldrin, dieldrin and endrin were not detected in all water samples. Only 4 compounds from 36 organophosphorus insecticides, fungicides and s‐triazine herbicides tested were detected in water samples collected during summer and autumn seasons from Rosetta branch. The concentration levels of these detected compounds, dimethoate, malathion, captan, and ametryne, ranged from 0.011 to 0.340 μg/l, respectively. Similar compounds during the same seasons as found in water of Rosetta branch were also detected in water of Damiatta branch except ametryne. The levels of the detected compounds (dimethoate, malathion and captan) ranged between 0.030 and 0.330 μg/l. The levels of detected organophosphorus insecticides, fungicides and s‐triazine herbicides were in the order: dimethoate > malathion > captan > ametryne.     

Characterization of contaminants in snapping turtles (Chelydra serpentina) from Canadian Lake Erie Areas of Concern: St. Clair River, Detroit River, and Wheatley Harbour

PCBs, organochlorine pesticides and dioxins/furans in snapping turtle eggs and plasma (Chelydra serpentina) were evaluated at three Areas of Concern (AOCs) on Lake Erie and its connecting channels (St. Clair River, Detroit River, and Wheatley Harbour), as well as two inland reference sites (Algonquin Provincial Park and Tiny Marsh) in 2001-2002. Eggs from the Detroit River and Wheatley Harbour AOCs had the highest levels of p,p'-DDE (24.4 and 57.9 ng/g) and sum PCBs (928.6 and 491.0 ng/g) wet weight, respectively. Contaminant levels in eggs from St. Clair River AOC were generally higher than those from Algonquin Park, but similar to those from Tiny Marsh. Dioxins appeared highest from the Detroit River. The PCB congener pattern in eggs suggested that turtles from the Detroit River and Wheatley Harbour AOCs were exposed to Aroclor 1260. TEQs of sum PCBs in eggs from all AOCs and p,p'-DDE levels in eggs from the Wheatley Harbour and the Detroit River AOCs exceeded the Canadian Environmental Quality Guidelines. Furthermore, sum PCBs in eggs from Detroit River and Wheatley Harbour exceeded partial restriction guidelines for consumption. Although estimated PCB body burdens in muscle tissue of females were well below consumption guidelines, estimated residues in liver and adipose were above guidelines for most sites.     

Evaluation of C18 solid‐phase extraction cartridges for the isolation of select pesticides and metabolites

Abstract

Nine different C₁₈ solid‐phase extraction (SPE) cartridges were evaluated for their efficiency at extracting nine pesticides and two s‐triazine metabolites from spiked deionized water samples. The SPE cartridges were found to contain nitrogen (N) and/or phosphorus (P) contaminants and varied in their extraction efficiency for certain pesticides and metabolites. Four of the nine SPE cartridges gave acceptable (70 to 120%) pesticide and metabolite recovery percentages, while five cartridges had marginal (50 to 70%) to poor (< 50%) recoveries. Statistical analyses showed that the poor to marginal recoveries found for three compounds could not be explained by considering several indigenous chemical and physical traits of the cartridge. It is suggested that proper SPE cartridge selection for pesticide recovery should be evaluated using several different cartridges.     

Biodegradation of polychlorinated biphenyls using biofilm grown with biphenyl as carbon source in fluidized bed reactor

This study investigated the use of biofilms in the biodegradation of polychlorinated biphenyls. The biofilm used was developed on modified cement particles using mixed microbial culture isolated from PCB-contaminated soil. The biofilm formed was first acclimatized to PCBs by feeding the reactor alternately with biphenyl and PCBs. The acclimatized biofilm was tested on simulated PCB-contaminated water containing Aroclor 1260 by using a three-phase fluidized-bed reactor operated in batch mode. The initial batch run yielded 80+/-2.38% PCB removal from medium in one day and 91+/-1.34% in 5 days. The percent PCB removal gradually increased in the succeeding runs reaching 92+/-2.48% in one day and a steady state value of 95+/-2.01% in 5 days from batch eight onwards. PCB removal from the medium was highest during the first day reaching 80-92%. The sudden decrease in PCB concentration was attributed to an initial adsorption of the PCB on the biofilm and then the compound was degraded gradually. Yellow intermediates were observed as the pH of the medium decreased. These intermediate products were further metabolized as indicated by the disappearance of the yellow substance.     

Evidence of degradation of polybrominated biphenyls in soil samples from michigan

Abstract

Soil samples obtained from the former polybrominated biphenyls (PBB) manufacturing site in Michigan were analyzed by gas chromatography and gas chromatography with mass spectrometric detection. The results indicate significant degradation of the PBB residue in the soil sample. The soil sample with the highest concentration of PBB has the greatest degree of degradation. Principal degradation products include 2,3’,4,4’,5‐pentabromo‐biphenyl, 2,2’,4,4’,5‐pencabromobiphenyl and two unidentified tetrabromobiphenyls.

The degradation pattern observed supports a photochemical decomposition mechanism. These degraded residues may be more toxic than the original Firemaster residues. The implications of the results are discussed.     

An eleven‐year study of chlorinated hydrocarbon insecticide residues in bovine fat in illinois, 1972–1982

Abstract

Bovine fat samples in Illinois were monitored for residues of chlorinated hydrocarbon insecticides from 1972 through 1982. The percentage of fat samples that were contaminated with all chlorinated hydrocarbons decreased during the 11‐year study. The percentage of samples contaminated with DDT and its analogs decreased most markedly from 82.4% in 1972 to 2.1% in 1982. The percentage of samples contaminated with aldrin/dieldrin and heptachlor/heptachlor epoxide began to decline in 1980 and continued to decrease through 1982.     

Persistence of residues in water and sediment op a fresh‐water lake after surface application of technical chlordane

Abstract

A fresh‐water lake, free from detectable pesticide residues before this study, was treated with a commercial formulation of technical chlordane. Water and sediment samples were analysed for chlordane residues 7, 24, 52, 279. and 421 days after treatment. Residues moved rapidly from the water to the lake bottom, supporting earlier results of a laboratory study with other organochlorines.

In water, α‐ and γ‐chlordane concentrations remained proportional to total chlordane concentrations, as determined by total‐peak area measurements of gas‐liquid chronatogrammes. But in bottom sediments, α‐ and γ‐chlordane were more persistent than other constituents of technical chlordane, supporting recent evidence that quantification of technical chlordane residues on the basis of γ‐chlordane quantification only (or that of a‐ and γ‐chlordane only), can lead to incorrect results and that this method, although simple and fast, should no longer be recommended.