Determination of oleandrin in tissues and biological fluids by liquid chromatography-electrospray tandem mass spectrometry

A rapid LC-MS/MS method, using a triple-quadrupole/linear ion trap mass spectrometer, was developed for the quantitative determination of oleandrin in serum, urine, and tissue samples. Oleandrin, the major cardiac glycoside of oleander (Nerium oleander L.), was extracted from serum and urine samples with methylene chloride and from tissues with acetonitrile. The tissue extracts were cleaned up using Florisil solid-phase extraction columns. Six replicate fortifications of serum and urine at 0.001 microg/g (1 ppb) oleandrin gave average recoveries of 97% with 5% CV (relative standard deviation) and 107% with 7% CV, respectively. Six replicate fortifications of liver at 0.005 microg/g (5 ppb) oleandrin gave average recoveries of 98% with 6% CV. This is the first report of a positive mass spectrometric identification and quantitation of oleandrin in tissue samples from oleander intoxication cases. The sensitivity and specificity of the LC-MS/MS analysis enables it to be the method of choice for toxicological investigations of oleander poisoning.     

Residue depletion of eprinomectin in bovine tissues after subcutaneous administration

A study of the tissue depletion of eprinomectin (EPR) subcutaneously administered to cattle at a dose of 500 mg per kg of body weight was carried out. EPR concentrations were determined in muscle, liver, kidney, and fat. Twenty-four parasite-free cross cattle were treated with the EPR injectable oil formulation. Three treated animals (two males and one female) were selected randomly to be sacrificed at 1, 3, 7, 14, 21, 28, 42, and 56 days withdrawal after injection. EPR residue concentrations were determined using HPLC with fluorescence detection. Muscle samples showed the lowest EPR concentrations throughout the study period. The highest EPR concentrations at all sampling times were measured in liver tissue, indicating that liver is a target tissue for EPR. EPR concentrations in all of the tissues analyzed were below the accepted maximum residue limits recommended by the European Union at 8 days posttreatment.     

Residue depletion of cefquinome in swine tissues after intramuscular administration

A high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection was developed for the detection of cefquinome (CEQ) residues in swine tissues. The limit of detection (LOD) of the method was 5 ng g(-1) for muscle and 10 ng g(-1) for fat, liver, and kidney. Mean recoveries of CEQ in all fortified samples at a concentration range of 20-500 ng g(-1) were 80.5-86.0% with coefficient of variation (CV) below 10.3%. Residue depletion study of CEQ in swine was conducted after five intramuscular injections at a dose of 2 mg kg(-1) of body weight with 24 h intervals. CEQ residue concentrations were detected in muscle, fat, liver, and kidney using the HPLC-UV method at 265 nm. The highest CEQ concentration was measured in kidney tissue during the study period, indicating that kidney was the target tissue for CEQ. CEQ concentrations in all examined tissues were below the accepted maximum residue limit (MRL) recommended by the Committee for Veterinary Medical Products of European Medical Evaluation Agency (EMEA) at 3 days post-treatment.     

Fats and oils. Determination of fat in body tissues and in food mixtures.

The official final action acid hydrolysis method, 14.019, for the determination of fat in foods was successfully applied, with slight modifications, to the analysis of homogenates of food, feces, and animal tissues as well as dry samples of mixed foods. In samples containing sucrose or fructose, it was necessary to carry out a fermentation procedure before acid hydrolysis to avoid problems encountered when these sugars were present.     

Residue depletion of florfenicol and its metabolite florfenicol amine in Swine tissues after intramuscular administration

A study of the tissue depletion of florfenicol (FF) administered intramuscularly twice to swine at a dose rate of 20 mg per kg of body weight at 24 h intervals was carried out. Forty healthy cross swine were treated with the FF injection formulation. Five treated animals were selected randomly to be sacrificed at 1, 3, 6, 9, 12, 14, 17, and 21 days withdrawal. FF and florfenicol amine (FFa) residue concentrations in muscle, liver, and kidney were determined using high-performance liquid chromatography (HPLC) with photodiode array (PDA) detection at 225 nm. Liver samples showed the lowest FF and the highest FFa concentrations throughout the experiment period. However, the highest total concentrations of FF and FFa during the study were found in kidney, which indicated that kidney is the target tissue for FF. The sum of FF and FFa concentrations in all tissues analyzed was below the accepted maximum residue limits recommended by the Agriculture Ministry of People's Republic of China and the European Union at 8 days posttreatment.     

Overview of physical-chemical methods for determining aminoglycoside antibiotics in tissues and fluids of food-producing animals

A survey of literature is presented dealing with physical-chemical methods for the detection and quantitation of aminoglycoside antibiotics (gentamicin, streptomycin, dihydrostreptomycin, and neomycin) that are used in food-producing animals. Recent developments in cleanup and determinative procedures, particularly liquid chromatography, for these compounds in fluids and tissues are emphasized. Little research has been done on residues in tissues compared with other biological matrices. This review also covers the chemistry, general characteristics, tolerances, and withdrawal times for the approved uses of these antibiotics in animals that are used for food.     

Cadmium and lead in human body fluids,air and drinking water in the area of Cracow

The amount of Cd and Pb in full blood and in the urine of males in Cracow and in a control area were measured and compared to the background of the level of these metals in air, dust fall and drinking water. The investigations were carried out in the years 1984–85. The mean Cd level in body fluids of Cracow's inhabitants was significantly higher than in the control group, and it amounted to: 0.54 μg Cd 100 mL^?1 in blood and 2.13 μg Cd L^?1 in urine. The Pb content in blood of the Cracow group (15.74 μg 100 mL^?1) was also significantly higher than in the control one, while the Pb level in urine was similar in both populations, reaching values below 10 μg L^?1. The mean annual Cd concentration in air and the Cd content in the dust fall in Cracow were 3 times higher than in the control area. The mean annual Pb concentration in Cracow's air exceeded the permissible Polish norm. In comparison with the control area, the Pb concentration level in air and its content in the dust fall in Cracow were 5 and 2 times higher, respectively. The level of Cd and Pb concentration in drinking water in Cracow and in the control area were much lower than the permissible values; however, in Cracow they were somewhat higher than in the control area.     

Validated extraction and cleanup procedures for polychlorinated biphenyls and DDE in human body fluids and infant formula

As part of an epidemiology study, extraction methods and extract cleanup procedures were developed and validated for polychlorinated biphenyls (PCBs) and DDE, an ubiquitous metabolite of DDT, in human milk, blood serum, and infant formula. Studies included quantitative and reproducible recovery of total lipids, and reproducible and reasonably high recoveries of these chlorinated compounds from the human body fluids and infant formula, including levels of environmental health interest. An extensive quality control and assurance program was designed for use with these methods. Some validation work on serum was done using radiolabeled 14C-Aroclor 1254. Dilution assays were developed to permit use of a constant procedure, which should minimize variability in results. Methods are based on selected organic solvent extraction and column chromatographic cleanup techniques and quantitation by electron capture gas chromatography (EC/GC). Using these extensively researched extraction and cleanup methods, the limits of detection for GC measurements were 10.0 and 2.00 ppb for PCBs and DDE, respectively, in milk and 4.00 and 0.80 ppb in serum.     

Determination of ammonium,amides, and soluble carboxylates in plant tissues

Methods for extraction and determination of ammonium, amides and soluble carboxylates in plant tissues are compared and discussed. The procedure recommended involves extraction of finely ground plant tissues with 0.2 M formic acid, determination of ammonium and amides in the extract by overnight alkaline hydrolysis and distillation in Conway microdiffusion dishes, measurement of extracted ammonium using Carlson's rapid diffusion‐conductivity instrument, and estimation of soluble organic acids by titration after separation and purification with ion exchange resins. The method described is reasonably rapid, and gives complete recovery and highly reproducible results. The final solution of organic acids is suitable for direct chromatographic analysis.     

Determination of olaquindox residues in swine tissues by liquid chromatography

A liquid chromatographic (LC) method is described for determination of olaquindox residues in swine tissues. The drug is extracted from tissues with acetonitrile, and the extract is evaporated to dryness. This residue is cleaned up by alumina column chromatography. LC analysis is carried out on a Nucleosil C18 column, and olaquindox is quantitated by ultraviolet detection at 350 nm. The average recoveries of olaquindox added to tissues at levels of 0.2, 0.1, and 0.05 ppm were 74.0, 68.6, and 66.3%, respectively. The detection limit was 2 ng for olaquindox standard and 0.02 ppm in tissues.     

Determination of ampicillin residues in fish tissues by liquid chromatography

A liquid chromatographic (LC) method is described for determination of ampicillin residues in fish tissues. The drug is extracted from tissues with methanol, and the extract is evaporated to dryness. This residue is cleaned up by Florisil cartridge chromatography. LC analysis is carried out on a Nucleosil C18 column, and ampicillin is quantitated by ultraviolet detection at 222 nm. Recoveries of ampicillin added to tissues at levels of 0.2 and 0.1 ppm were 73.2 and 61.5%, respectively. The detection limit was 3 ng for ampicillin standard, and 0.03 ppm in tissues.     

Determination of pentachlorophenol in animal tissues: a Canadian perspective

Analytical methods for pentachlorophenol (PCP) residues in edible animal tissue have been reviewed, with particular reference to gas chromatographic methods of analysis. Results of analyses demonstrate that significant residues of PCP can persist for several weeks in animals exposed to contaminated bedding. National surveys in Canada have found that the incidence of PCP residues in pork in excess of 0.1 ppm was reduced from 32% of survey samples in 1981-1982 to 6.6% of samples tested in 1987-1988. An interlaboratory sample exchange among Canadian laboratories demonstrated that the PCP analytical method currently used by Agriculture Canada could be successfully transferred to other laboratories. An exchange of samples between regulatory laboratories of Agriculture Canada and the Food Safety and Inspection Service of the U.S. Department of Agriculture (USDA) demonstrated equivalency of results for the 2 methods currently used in the respective laboratories, with relative standard deviations for analytical results ranging from 4.4 to 22.2%.     

Determination of dioxins and furans in foods and biological tissues: review and update

Determination of trace residues of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) in various matrixes is carried out by a limited number of laboratories in the United States, Canada, and other countries. Current methods for analysis of foods and biological tissues include a combination of preparation, extraction, cleanup, isolation, determination, and identity confirmation procedures. Soxhlet, liquid/liquid, solid-phase, and column extraction procedures are used as well as treatment with acid or base before solvent extraction. Cleanup and isolation steps include sulfuric acid partitioning; adsorption chromatography on Florisil, silica gel, or alumina; gel permeation chromatography; multi-stage column chromatography on sulfuric acid silica and alkali silica; carbon column chromatography; and liquid chromatography fractionation with size exclusion, normal-phase, and reverse-phase columns. Activated carbon and multistage chromatographic columns are widely used in cleanup schemes. Isomer-specific identification and quantitation of PCDD and PCDF congeners at parts-per-trillion levels or lower are carried out by high resolution (capillary) gas chromatography (HRGC) and multiple ion detection mass spectrometry. In addition to chemical methods, bioassay procedures have been recommended (e.g., use of monoclonal antibodies, for immunoassay determination of PCDDs and PCDFs).