Rapid multiresidue procedure for the determination of pesticides in anhydrous lanolin and lanolin-containing pharmaceutical preparations utilizing gel permeation chromatography cleanup with gas chromatographic and mass spectrometric techniques

To read the full-text of this research, you can request a copy directly from the authors.


The proposed multiresidue method has been used to quantify residues of 17 different pesticides found in anhydrous lanolin and lanolin-containing pharmaceutical preparations. Lanolin waxes are separated from the residues using automated gel permeation chromatography (GPC). Resulting eluates are injected directly into gas chromatographs using a variety of wide-bore capillary columns. A flame photometric detector in the phosphorus mode (FPD/P) is used to quantify organophosphorus pesticides. Organochlorine residues are determined through the use of electrolytic conductivity detection (ELCD). Several residues were identified or confirmed using GC with mass spectrometry. Results of analysis of samples of anhydrous lanolin collected in 1991 were similar in types and levels of residues to those analyzed in 1989. Diazinon residues were most prominent, with levels frequently in excess fo 20 mg/kg. Additionally, some lanolin-containing pharmaceutical preparations collected in 1988 and 1992 were found to have patterns of residues similar to those encountered in anhydrous lanolin. However, the highest level of residues encountered in these preparations was only 6.82 mg/kg (diazinon). Recoveries from anhydrous lanolin samples fortified with 12 organochlorine and organophosphorus pesticides ranged from 97 to 110%.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... The two first steps are considered to be the most critical, since the achievement of the appropiate fractions needed in further analysis, depends on them [8]. In the clean-up step, the most universally system applied is gel permeation chromatography (GPC)91011. Polymers used in the GPC columns don't involve losses of pesticides by adsorption. ...
Full-text available
In this paper the efficiency of a method for the separation and identification of pesticides in lanolin is presented. Theses pesticides belong to the organophosphorous and synthetic pyrethroids families. After the gel permeation chromatography, pesticides are separated from lanolin into two fractions corresponding to the two families, which simplify subsequent analysis by gas chromatography.
... Some wool scouring industries remove the grease from the liquid phase, because the product resulting from purifying the grease is known as lanolin, which is widely used as a moisturizer in cosmetics (2) and media for some pharmaceutical preparations (3,4) because of its high compatibility with human skin oils. Unfortunately, pesticides have been found in samples of lanolin, as revealed by other studies (2,5). ...
Full-text available
In this study, the efficiency of a clean-up method by gel permeation chromatography (GPC) for the separation of pesticides from lanolin is analyzed. The pesticides analyzed belong to two different families, organophosphorous and synthetic pyrethroids. Lanolin, a standard mixture of the pesticides, and a lanolin—pesticides mixture are injected in a GPC column. The recoveries and elution times from the GPC column of lanolin (by a gravimetric method) and pesticides (by gas chromatography—electron capture detector) are determined. From this column, a good separation of the lanolin—pesticides mixture is observed.
... Although the influence of these complex matrices on the analytical method performance is recognised [1,2,5], the development of efficient procedures has been published in the literature [1,2,4,5,9]. William Jones [1] studied the effects of modifications in the procedure previously described [10,11] for the determination of organochlorine and organophosphorus pesticides. The experimental conditions were also optimized for the analysis of pyrethroid pesticides. ...
Full-text available
In the present study an evaluation was made of a method for the determination of organochlorine pesticide residues in ethoxylated lanolin. Samples were homogenized with Celite, transferred to chromatographic columns, prepacked with silica gel deactivated to 10%. The pesticide elution was processed with n-hexane-dichloromethane and the concentrated eluate was analyzed using gas-liquid chromatography (GC) with electron capture detection (ECD). The composition of the elution solvent was a significant factor for the recovery of the pesticides. Mean recoveries obtained for fortified samples ranged from 87 to 94% for p,p'-DDE, dieldrin, endrin, p,p'-DDD and p,p'-DDT. Optimization of the experimental conditions resulted in a small-scale method that combines extraction and cleanup in a single step.
A new method was developed for the simultaneous determination of 20 organophosphorus and organochlorine pesticides in greasy wool by GC/MS system using a three-way splitter and backflush. The pesticide residues in greasy wool were extracted by supercritical CO 2 fluid extraction system and cleaned up by N-aluminum solid phase extraction column. The detection procedure was carried out by GC/MS system combined with micro-electron capture detector and nitrogen phosphorus detector. With this method, the accurate qualitative and quantitative results could be obtained simultaneously, and the use of backflush reduced system contamination and extended the column lifetime. The average recoveries of pesticides spiked at three levels in greasy wool were 85.6%-120.9%, and the relative standard deviations were 1.2%-17.3%. The method shows little interferences, good repeatability and high automation level. It is suitable for the simultaneous determination of organophosphorus and organochlorine pesticides in greasy wool samples.
Supercritical fluid extraction with CO2 was investigated as a sample cleanup procedure for the gas chromatographic analysis of pesticide residues in wool wax. Spiked samples were used to optimize the extraction parameters. Recoveries of between 85% and 108% with relative standard deviations of 2−8% were obtained for a range of pesticides that represented those most likely to be found in raw wool wax as a result of treating sheep with legal pesticides to control ectoparasites. Keywords: Analysis; carbon dioxide; gas chromatography; lanolin; pesticides; supercritical fluid extraction; wool wax
The analysis of 48 different pesticide residues in raw wool wax and lanolin by the use of gel permeation and gas chromatography is described. The gel permeation conditions have been optimized for the recovery of the pyrethroids, which are currently widely registered for use on sheep to control ectoparasites. Coeluted wool wax peroxides, which were believed to be responsible for the initial failure of the narrow bore capillary gas chromatography columns used, were either removed or destroyed by passing the gel permeation eluant through alumina or by treatment with aqueous sodium metabisulfite. Wool wax was spiked with pesticides at three levels. Average recoveries at all levels ranged from 70% to 108%. Keywords: Analysis; gas chromatography; gel permeation chromatography; lanolin; pesticides; wool wax
Full-text available
An efficient, fast, and accurate matrix solid-phase dispersion sample cleanup procedure was developed specifically for the determination of pesticide residues in lanolin. The scope of the method for organophosphorus, organochlorine, and pyrethroid insecticides is the same as that of official methods from various pharmacopeias. After lanolin dispersion on C18 bonded silica, pesticides are eluted with acetonitrile saturated with n-hexane. Recoveries ranged from 83 to 118% with RSD values of < 20% for most pesticides listed, in compliance with the requirements of European and U.S. pharmacopeias.
A stepwise approach was used to develop a supercritical fluid extraction (SFE) method for analysis of synthetic pyrethroids (SPs) on a wool matrix, commencing with a simple inert matrix to examine the solubility of the pyrethroids in the extraction fluid CO(2) and then extended to the real wool matrix. Chemometric approaches were used to determine the SFE optimum conditions. It was found that pyrethroids were readily extractable from an inert matrix over a wide range of pressure (170-350 atm) and at low temperature (<90 degrees C). Subambient hexane efficiently trapped the compounds from the depressurised fluid. Excessively high pressure and temperature resulted in poor trapping, isomerisation and possibly degradation of some components. With spiked wool samples method modifications focused on reducing the coextraction of grease, a bulk matrix component of raw wool. By using alumina (containing 8% moisture) and operating the extraction at 50 degrees C, 200 atm for 60 min, sufficiently clean extracts of pyrethroids suitable for gas chromatography-electron-capture detection analysis were obtained. The recoveries of all SPs were satisfactory (78-101%) over the range of 0.5-5 microg/g levels of these compounds. The precision of the entire analysis procedure was comparable to the conventional Soxhlet extraction method. Detection limits of some commonly used SPs for sheep treatment were also evaluated. Comparable results relative to those achieved by solvent extraction for incurred wool samples were obtained with a recovery of 81-85%. The results, however, suffered high uncertainties (R.S.D. approximately 19-24%) due to the small amount of wool sample taken in each extraction and the suspected inhomogeneity of the wool. Different persistences of cypermethrin isomers in wool were observed.
A methodology for multi-class pesticide determination at trace level in lanolin is presented. Gel permeation chromatography on a Bio-Beads SX-3 column followed by a dual GC chromatographic determination has been developed. The effluent of the analytical column (50% diphenyl-methyl- or 14% cyanopropyl-phenylpolysiloxane) was split into an electron-capture and a nitrogen-phosphorus detection system. The chromatographic system was optimised for 28 pesticides commonly used to control sheep pests and corresponding to organochlorine, organophosphorus and pyretroid classes. Identification has been carried out by gas chromatography coupled to negative chemical ionization mass spectrometry. Recoveries ranged from 72 to 94% and the detection limits from 20 to 97 ng/g depending on the pesticide class, the RSDs were below 10%. Finally, the developed analytical methodology has been successfully applied to the determination of pesticides in several lanolin samples.
Diazinon is an organophosphorus insecticide (OPP) that is used as a pesticide for Chilo suppressalis (WLK) (Lep., Pyralidae) in rice fields. The extraction of diazinon from soil and the stems of rice plants has been carried out by microwave-assisted extraction (MAE) and the results compared with ultrasonic extraction (USE). The best parameters for MAE are hexane-acetone (8:2 v/v) as a solvent, a 2.5 min extraction time, and 20 ml of the solvent volume. Also, surface-water samples of the rice fields were extracted by solid phase extraction (SPE) using a C18 disc. The optimum conditions of SPE were a sample volume of 750 ml, a pH of 7 and high ionic strength of water. The extracted samples were analyzed by gas chromatography-mass spectrometry (GC-MS). The relative standard deviation (RSD) and regression coefficients related to the linearity were <3.5% (n = 5) and 0.99, respectively. The limit of detection (LOD) is 0.1 ng ml(-1) with selected ion monitoring (SIM) at 137 m/z. The average recoveries of diazinon in soil and stem samples by MAE and surface-water by SPE were 98% (+/-3), 94% (+/-5) and 87% (+/-3), respectively. In June, the concentration of diazinon in soil and stem samples of the rice plants in Guilan province is high (55 ng ml(-1)) and in September is low (2 ng ml(-1)). In surface-water samples, the results are converse. In November, diazinon can not be detected in soil, stem or surface-water samples. Diazinon is degraded to diethylthiophosphoric acid. Also, three microorganism genera (Pseudomonas sp, Flavobacterium sp and Agrobacterium sp) have been found to degrade diazinon in soil and surface water.
A gel permeation chromatography (GPC) system for the rapid separation of industrial chemicals and organophosphate and chlorinated pesticides from fats has been developed. The system uses Bio-Beads SX-3 with a methylene chloride-n-hexane (50:50 v/v) solvent system. This gives good recoveries for a wide range of industrial chemicals and pesticides. Less than 1% fat remained in the pesticide fraction.
A method is described for the determination of pesticide residues in lanolin. Lanolin may be contaminated with pesticides due to treatment of sheep or storage of greasy wool in a warehouse. Residual pesticides were isolated by Florisil column chromatography and fractionated into two portions. Each fraction was injected into capillary gas chromatographs equipped with electron capture and flame photometric detectors. Results of recovery tests for organochlorine pesticides (BHC's, aldrin, dieldrin, and DDT's) and organophosphorus pesticides (diazinon and fenitrothion) ranged from 75% to 110% at two concentrations. Quantitation limits ranged from 0.01 to 0.05 ppm for organochlorine pesticides and 0.1 ppm for organophosphorus pesticides. Several lanolin samples were examined according to this method. An older lanolin sample was contaminated with several pesticides. A few unknown peaks were identified by the combination of capillary GC with mass spectrometry and atomic emission.
A sensitive, flame photometric procedure for organophosphate residue determination using automated gel permeation chromatographic cleanup is described. Elution volumes of 26 parent and major metabolites of four representative organophosphates were determined. Fortification of 12 sample types with six parent compounds and one metabolite at 0.05-0.10 ppm yielded average recoveries of 83-103%. To demonstrate applicability of the method to multiresidue screening, three samples were fortified with eight organophosphates and analyzed simultaneously.
In the proposed method, a light petroleum solution of lanolin (wool fat) is adsorbed on diatomaceous earth in an Extrelut column, and the pesticides are eluted with acetonitrile saturated with light petroleum. After evaporation to a small volume, the extract is subjected to solid-phase extraction (SPE) on a C-18 column. The acetonitrile eluate is evaporated to dryness and the residue is taken up in light petroleum. Organophosphorus pesticides are determined by temperature-programmed gas chromatography (GC) on a wide-bore column using a flame photometric detector in the phosphorus mode. Organochlorine pesticides are determined after miniaturized Florisil cleanup by classic GC on an OV-17/QF-1 packed column, using an electron capture detector. This procedure is more rapid and straightforward than the time-consuming AOAC extraction method, 29.014. Cleanup was better and the results obtained were comparable. Recoveries for 13 organochlorine and organophosphorus pesticides, frequently found in lanolin, ranged from 80 to 90%.
The U.S. Food and Drug Administration conducts the Total Diet Study to determine dietary intakes of selected pesticides, industrial chemicals, and elements (including radionuclides). The current study, which reflects significant redesign implemented in April 1982, involves retail purchase of foods representative of the "total diet" of the U.S. population, preparation for "table-ready" consumption, and individual analyses of 234 items depicting the diets of 8 population groups. The dietary revision was based on 2 nationwide food consumption surveys. The data presented represent 8 food collections (also termed "market baskets") in regional metropolitan areas during the 2-year period. Dietary intakes of over 100 analytes are presented for the 8 population groups, which range from infants to elderly adults. Intakes of selected population groups are compared with representative previous findings. As in the past, average daily intakes are within acceptable limits.
A fast, single-step, and efficient partition between n-hexane and acetonitrile on ready-to-use, disposable mini-columns of Kieselghur-type material has been developed for the cleanup of fatty extracts for organophosphate (OP) pesticide residue determination by gas chromatography with flame photometric detection. Nine OP pesticides (diazinon, etrimfos, chlorpyrifos-methyl, pyrimiphos-methyl, chlorpyrifos, bromophos, bromophos-ethyl, malathion, fenitrothion) most commonly used for protection of stored cereals, oil seeds, and legumes were separated from up to 2.0 g lipidic material with recoveries between 80 and 107% at spiking levels ranging for the different compounds from 0.1 to 5.0 ppm.
The foods and diets of FDA's Total Diet Study have been revised according to current food consumption patterns. A representative subset of 234 foods, selected from aggregated NFCS and NHANES II data, is collected and analyzed by the Kansas City Field Office Laboratory for 11 essential minerals and more than 120 chemical contaminants. The daily intake by weight of these 234 foods has been extrapolated to represent 100% of the usual diet for eight age-sex groups. These extrapolated food intakes will be used to assess daily contaminant and mineral intakes. The revised food list and diets will be used until the results of another national food consumption survey show the necessity to further revise the diets for the Total Diet Study Program.
Gaschromatographishe Bestimmung von Orga-nochlor-und Organophosphorruchstanden in Dekorativen Kosmetika und Hautpflegenmitteln. Dtsch. Lebensm. Rund-sch
  • M Cetinkaya
Cetinkaya, M. Gaschromatographishe Bestimmung von Orga-nochlor-und Organophosphorruchstanden in Dekorativen Kosmetika und Hautpflegenmitteln. Dtsch. Lebensm. Rund-sch. 1988,84, 388-391.
Hazards Negligible but Checks of Lanolin for Pesticides Continue; FDA Public Affairs Statement No. T88-00
  • Fda
FDA. Hazards Negligible but Checks of Lanolin for Pesticides Continue; FDA Public Affairs Statement No. T88-00; FDA:
FDA. Pesticides Analytical Manual Section 211.14d. Food Chemical News Australian's Set Pesticide Tolerance in Lanolin " ; Food Chemical News
  • Washington
  • Dc
Washington, DC, 1988. FDA. Pesticides Analytical Manual; FDA Washington, DC, 1991; Vol. 1, Section 211.14d. Food Chemical News. " Australian's Set Pesticide Tolerance in Lanolin " ; Food Chemical News: Washington, DC, 1988; September 19, p 23.
Environmental Contaminants in Table-Ready Foods from the Total Diet Program of the Food and Drug Administration
  • D L Heikes
Heikes, D. L. Environmental Contaminants in Table-Ready Foods from the Total Diet Program of the Food and Drug Administration. In Food Contamination from Environmental Sources; Nriagu, J. O., Simmons, M. S., Eds.; Wiley: New York, 1990; Vol. 23, Chapter 2.
Loading of Mother's Milk with Chlorinated Hydrocarbons from Lanolin-Containing Cremes
  • H A Meemken
  • K Habersaat
  • W Groebel
Meemken, H. A.; Habersaat, K.; Groebel, W. Loading of Mother's Milk with Chlorinated Hydrocarbons from Lanolin-Containing Cremes. Lebensmittelchem. Gerichtl. Chem. 1982,36,51-53.
Biocides in Humans. Residues in Human Milk and Organs. Erhaehr.-Umsch
  • B Mueller
  • H Schroeder
Mueller, B.; Schroeder, H. Biocides in Humans. Residues in Human Milk and Organs. Erhaehr.-Umsch. 1982, 29, 359-362.