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Biomedical subjects

H Beernaert

Publications and source records attributed to H Beernaert.

18 recordsLinked to original sources
PubMed1991

A simple and quick gas chromatographic method for the determination of propham and chlorpropham in potatoes.

This study describes a gas chromatographic method for the quantitative determination of residual propham and chlorpropham in potatoes. Both herbicides are extracted from the foodstuff with methylene chloride. After centrifugation and concentration, propham and chlorpropham are quantitatively determined by gas chromatography thermionic detection using a fused silica capillary column CP Sil 5CB. 2-Chloraniline is used as internal standard. Recoveries of 100 +/- 15% and 99 +/- 10% have been obtained for propham and chlorpropham in blank samples spiked at the level of 0.5, 1.0 and 5.0 mg/kg. The absolute detection limit for both compounds is 1 ng corresponding to 0.1 mg/kg. Of the 161 samples of fresh potatoes analysed using this method, 136 contained residues of these herbicides and 18 of them (11%) exceeded the maximum tolerated value of 5 mg/kg.

Carbamates↗
PubMed1991

Determination of levamisole and thiabendazole in meat by HPLC and photodiode array detection.

An HPLC method for the analysis of levamisole and thiabendazole has been developed with recoveries varying over 63-75%. The two anthelmintics are extracted from meat with ethyl acetate, purified by liquid/liquid extraction and analyzed quantitatively on a mu Bondapak C18 column. The optimum detection is achieved by means of a photodiode array detector at 240 nm for levamisole and at 300 nm for thiabendazole. The detection limits for both compounds in meat are 25 micrograms/kg and 5 micrograms/kg, respectively.

Animals↗
PubMed1991

Cimaterol and clenbuterol residue analysis by HPLC-HPTLC in liver.

A method has been developed for the analysis of cimaterol and clenbuterol residues in liver, with detection limits of 0.25 micrograms/kg and 0.5 micrograms/kg, respectively. The recovery varied from 55% to 60%. After extraction, a clean-up procedure with Baker-spe C-18 columns was performed. The two chemical compounds of interest were eluted with methanol. Cimaterol and clenbuterol were quantitatively determined by high-performance liquid chromatography (HPLC) using an RP-Select B (5 microns) column and a post-column reaction procedure. The positive results were confirmed by high-performance thin-layer chromatography (HPTLC) as this technique reaches the same level of sensitivity as the HPLC method.

Adrenergic beta-Agonists↗
PubMed1991

Salbutamol identification in liver and urine by high-performance thin-layer chromatography and densitometry.

This paper describes a rapid method for the identification of salbutamol in liver and urine. Salbutamol is extracted from liver with an acid solution, purified on Baker columns and eluted with methanol. After derivatization, salbutamol is detected on HPTLC plates as a blue spot. Urine samples are directly purified on the C18 columns and then the same procedure is followed as for the liver samples. Using this screening method, salbutamol can be semi-quantitatively determined at the micrograms/kg level.

Albuterol↗
PubMed1991

Determination of thiabendazole residues in meat by HPLC using ultraviolet and fluorometric detection.

An HPLC method is described for the residue analysis of thiabendazole in meat. The recovery varies from 62 to 75%. Thiabendazole is extracted from the tissue using 3 mol HCl, eluted from the Extrelut-20 column with dichloromethane and then injected onto a C18 column. The optimum conditions for detection are described using ultraviolet and fluorescence spectroscopy. The sensitivity is such that thiabendazole can be determined at a level of 5 micrograms/kg meat. The absolute detection limit with fluorometry is 100 pg.

Animals↗
PubMed1989

Determination of residual bromopropylate and coumaphos in honey and honeycomb by capillary gas chromatography.

This study describes a method for the quantitative determination of residual bromopropylate (BP) and coumaphos (Cph) in honey and honeycomb. It is based on a reversed phase extraction technique on sorbent octadecyl. Both phyto-pharmaceuticals are determined by electron-capture using a fused silica capillary column CP Sil 5 CB. The absolute detection limit for BP and Cph is 2.5 and 5 pg, respectively. Recoveries of 99.6% and 94.4% are obtained for samples fortified at levels of 400 micrograms BP/kg and 1,000 micrograms Cph/kg. Twelve samples of honey and 8 samples of honey-honeycomb have been analysed using this method. BP and Cph could not be detected in the honey samples. Samples of honey-honeycomb recently treated with Perizin (Cph) and Folbex VA (BP) contained different amounts of BP and Cph.

Animals↗
PubMed1989

Headspace--gas chromatographic determination of inorganic bromide residues in vegetables.

This study describes a headspace gas-chromatographic method for the quantitative determination of inorganic bromide in vegetables. Different parameters influencing the reaction of the bromide ion into 2-bromoethanol have been investigated. The analysis of 2-bromoethanol is performed by the headspace--electron capture--gas chromatographic technique using a fused silica capillary column CP wax 52 CB. Recoveries of 99.75% +/- 4.1% have been obtained for bromide concentrations of 5 up to 350 mg/kg. Sixty-nine samples have been analysed by this method. The results are in good agreement with the normal bromide extraction method. The absolute detection limit is 2 ng corresponding to 0.5 mg Br-/kg for a slit ratio of 1:10.

Bromides↗
PubMed1989

Clenbuterol residue analysis by HPLC-HPTLC in urine and animal tissues.

A method for clenbuterol residue analysis in urine and animal tissues has been developed. The detection limits are 0.25 micrograms/l and 0.5 micrograms/kg, respectively. The recovery in urine varies from 85% to 90% and in animal tissues from 70% to 74%. The beta 2-agonist was liberated from the tissues by an enzymatic digestion, purified on Chem Elut columns using alkaline conditions and extracted with 0.01 mol/l HCl. Clenbuterol was quantified by high-performance liquid chromatography (HPLC) on a RP-8 column and a post-column reaction procedure. High-performance thin-layer chromatography (HPTLC) was performed on silica gel 60 plates and clenbuterol visualized by means of the modified Ehrlich's TLC spray reagent. Since this method is sensitive, as is HPLC, it was used to obtain a confirmation and to exclude false positive results.

Animals↗
PubMed1989

Determination of residual 1,3-dichloro-2-propanol in protein hydrolysates by capillary gas chromatography.

This study describes a method for the quantitative determination of residual 1,3-dichloro-2-propanol in protein hydrolysates. The method is based on a continuous micro-steam distillation solvent extraction technique. The quantitative determination is performed by electron-capture gas chromatography using an "on column" injector and a fused silica capillary CP wax 52 CB column. The absolute detection limit for 1,3-dichloro-2-propanol in soy sauces is 10 pg and recoveries of 75.8% and 82.7% with a standard deviation of 4.0% and 2.5% are obtained for samples fortified in the range of 1 mg/kg and 0.1 mg/kg respectively.

Chlorohydrins↗
PubMed1989

Determination of residual tetrachloroethylene in olive oil by headspace-gas chromatography.

This study describes a method for the quantitative determination of residual tetrachloroethylene or perchloroethylene (PCE) in olive oil by headspace-gas chromatography. The analysis of the chlorinated product is performed by electron-capture gas chromatography, using a fused silica capillary column, CP Sil 8 CB. The absolute detection limit for PCE was 1 pg. Forty samples of olive oil and 5 other commodities have been analysed. Only one sample exceeded the proposed maximum level of 1 mg/kg.

Chromatography, Gas↗
PubMed1988

Determination of fumigants in cereals and cereal products by capillary gas chromatography.

This study describes two methods for the quantitative determination of the residual fumigants ethylene dichloride (EDC), carbon tetrachloride (CCl4), trichloroethylene (TCE), ethylene dibromide (EDB) and tetrachloroethylene (PCE) in cereals (especially wheat) and other foodstuffs. In the first method, a micro steam distillation- solvent extraction apparatus is used, while the second method is based on a headspace technique. For the quantitative determination of carbon tetrachloride in cereals, the multiple headspace technique is not retained because it is too time-consuming. The analysis of the different fumigants is performed by electron-capture gas chromatography, using a fused silica capillary column, CP sil 8 CB. With the steam distillation-solvent extraction method, recoveries from 95.9% to 100.5% are obtained for the fumigants, added at two different levels. The standard deviation varies between 1.1% and 6%. Using the simple headspace technique, recoveries from 73.5% to 85.1% with a standard deviation of between 1.7% and 6.6% have been reached for the fumigants in cereals fortified at two different levels. The absolute detection limits for the five fumigants EDC, CCl4, TCE, EDB and PCE, in both methods, are 30, 0.25, 1.1, and 0.5 pg, respectively.

Chromatography, Gas↗
PubMed1988

A two-dimensional high-performance thin-layer chromatographic screening method for sulphonamides in animal tissues.

A procedure for the identification of sulphonamides in edible animal tissues by two-dimensional high-performance thin-layer chromatography is described. Sixteen sulphonamides can be detected at an absolute level of 10 ng. The absolute detection limit of the sulphonamide standards is 1 ng. After extraction of the sulphonamides with chloroform/acetone, the acidified extract is concentrated and purified using a cation-exchange solid phase extraction column. The column is treated with ammonia vapour and the sulphonamides are then eluted with methanol. Blank samples of edible animal tissues spiked with sulphonamides (frequently used in Belgium) result in very good separation.

Animals↗
PubMed1985

Determination of residual ethylene dibromide in cereals by glass capillary gas chromatography.

This study describes two methods for the quantitative determination of residual ethylene dibromide (1,2-dibromoethane) in cereals, especially wheat, and in dried fruit. The first method is based on a solvent-extraction technique; in the second a continuous micro steam-distillation--solvent-extraction apparatus is used. The quantitative determination of ethylene dibromide is performed by electron-capture gas chromatography using a glass capillary column coated with CPwax 51. The absolute detection limit for EDB is 0.5 pg and recoveries of 82 and 98% resp. are obtained for samples with EDB added in the range of 10 to 50 micrograms/kg. 75 samples of cereal products and 19 samples of dried fruit have been analysed with the solvent extraction method. For 22 samples the micro steam-distillation-solvent-extraction technique has been used.

Carcinogens↗
PubMed1984

Rapid determination of chlorobutanol in milk by glass capillary gas chromatography.

A rapid method for the determination of chlorobutanol(1,1,1-trichloro-2-methylpropan-2-ol) in milk is described. The method is based on a steam-distillation solvent-extraction technique and a quantitative determination of chlorobutanol by gas chromatography using a glass-capillary column coated with Carbowax 20M and 2,2,2-trichloroethanol as internal standard. The detection limit is 1 pg and recoveries of chlorobutanol are between 93 und 99%. Fifty-two milk samples have been analysed.

Animals↗