Rapid Method For Simultaneous Determination Research Articles

Simultaneous Determination of Organonitrogen and Carbamate Pesticides in Foods by an Internal Standard Method Based on Retention Indices in Dual-Column Gas Chromatography

A method for accurate and simple determination of 28 kinds of organonitrogen and 7 kinds of carbamate pesticides in foods was developed. The pesticides in foods were extracted using a method for rapid simultaneous determination of pesticide residues recommended by the Ministry of Health and Welfare. The pesticides co-injected with retention index standards (M-Series) were determined with a dual-column gas chromatograph equipped with ATD. The identification was based on retention indices and the quantitation was done by a multi-internal standard method. This technique provides superior reproducibility of identification and accuracy of quantitation.

Determination of Sulfadimethoxine and Sulfamethazine Residues in Animal Tissues by Liquid Chromatography and Thermospray Mass Spectrometry

A simple, sensitive, and rapid method for simultaneous determination of sulfamethazine and sulfadimethoxine residues in animal tissues by liquid chromatography (LC) with on-line confirmation by thermospray mass spectrometry is reported. Tissue extracts, after cleanup on C18 cartridges, were injected into a reversed-phase C18 column, and the sulfa drugs were determined by ultraviolet (UV) detection at 265 nm. On-line confirmation of sulfamethazine and sulfadimethoxine in the extracts by mass spectrometry was obtained by feeding the sulfa drugs eluting from the chromatographic column after UV detection directly into the ion source of a mass spectrometer with a thermospray ionization LC interface. Analytical results obtained with the LC method, which has detection limits of 2 and 10 ng/g of tissue, for sulfamethazine and sulfadimethoxine, respectively, compared favorably with those obtained with the official thin-layer chromatographic-densitometric method.

A rapid and semi-quantitative method for the detection of autoantibodies by multiple spot immunoassay

A method for rapid simultaneous determination of multiple autoantibodies in sera has been developed. 42 different antigens were coated onto a nitrocellulose membrane in a miniblotter apparatus with 42 lanes. The membrane was also coated with different concentrations of human IgG to create a standard curve. The blotting apparatus after coating, blocking and washing was turned 90° so that all lanes crossed the antigen coated lanes. Thereafter, 42 sera were incubated with the antigens. After this stage the membrane was treated as in the usual dot-blot procedure. After incubation with alkaline phosphatase labelled anti-human IgG, staining and drying of the membrane, the staining intensity of individual lanes was scanned into a data file and analyzed by computer. By this method it was possible in 4 h to examine 42 sera for autoantibodies against 42 antigens, i.e., more than 1600 tests. Furthermore, the amount of antibody could be semi-quantified, using the IgG standards. The method should be useful for rapid screening of autoantibodies in a routine laboratory.

Simultaneous Diagnosis of Coagulation Factor XIIIA (F13A) and Plasminogen (PLG) Phenotypes by Polyacrylamide Gel Isoelectric Focusing

In this paper, we report a simple rapid method for simultaneous determination of Coagulation Factor XIIIA (F13A) and plasminogen (PLG) phenotypes by PAGIF with a nominal pH range of 3.5 to 10, followed by immunofixation and silver stain. Critical considerations concerning the conditions of molecular separation and detection strategies are also presented.

Determination of Carbimazole and Methimazole by First and Third Derivative Spectrophotometry

Abstract A rapid method for simultaneous determination of both carbimazole and methimazole by third derivative spectrophotometry is presented. First derivative spectrophotometry is also applied for selective determination of carbimazole in the presence of methimazole. By measuring the absolute values of the first (for carbimazole) and third derivative curves for the mixture, the concentration of each component can be calculated directly without interference from the other. The method was proved using prepared mixtures of the two drugs. The mean accuracies for the determination of carbimazole by first and third derivative spectrophotometry were found to be 100.02 ± 0.29, 100.07 ± 0.17, respectively and 99.97 ± 0.09 for methimazole by third derivative spectrophotometry. The proposed procedures were successfully applied for the analysis of carbimazole in tablet form and its validity was further checked using the standard addition technique.

Simultaneous Determination of Ten Kinds of Organochlorine Insecticides in Beef by Gas Chromatography

A simple and rapid method for simultaneous determination of 10 kinds of organochlorine insecticides (ß-BHC, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, p,p′-DDT, p,p′-DDE, p,p′-DDD, t-chlordane) in beef was established. The pesticides were extracted from samples with acetone hexane (3:1) mixture, and purified by Florisil column chromatography, then determined by use of a gas chromatograph equipped with an electron capture detector (ECD-GLC). Recoveries of the 10 pesticides added to beef at 0.02 ppm and 0.1 ppm were within the range of 63.9 - 89.0% and 76.8 - 90.5% by the proposed method, respectively. One hundred and twenty six samples of Australian beef received at the Osaka and Kobe quarantine stations from August to December in 1987 were analyzed, and only one sample was over the limit of dieldrin (+aldrin) referring to Japanese temporary tolerance.

Extraction, separation, and detections of 14C-diazepam and 14C-metabolites from brain tissue of mature and old rats.

A rapid method for simultaneous determination of brain concentrations of diazepam and each of its three major metabolites in brain tissue by a reverse isotope dilution procedure is presented. Radiolabeled diazepam and metabolites were extracted from brain tissue of mature and senescent rats with ethyl ether. After the ether was evaporated the benzodiazepines were separated from the residue by passing the water soluble portion through C-18 bonded-phase extraction columns. High pressure liquid chromatography (HPLC) was used to separate the benzodiazepines from each other. Reverse isotope dilution analysis was used to quantify diazepam and its metabolites. The percent recovery of diazepam and its metabolites from the brain of mature or senescent rats did not vary significantly.

A rapid method for simultaneous determination of carbon and hydrogen in petroleum products, with a specific infrared detector

A new carbon-hydrogen analyser is described. It differs from others in that it uses two specific infrared detectors. The basic principle of this analyser is a flash combustion of the sample in oxygen in a vertical furnace, and the water and carbon dioxide are measured with the two infrared detectors in series, the signals from the detectors being automatically integrated. The analyser determines carbon and hydrogen in petroleum products simultaneously in 3 min. The standard deviation for samples weighing about 1 mg is 0.3% for carbon (85%) and 0.06% for hydrogen (12%).

Rapid method for simultaneous determination of phenobarbital, diphenylhydantoin and their main hydroxylated metabolites by nitrogen-selective gas chromatography.

Rapid method for simultaneous determination of phenobarbital, diphenylhydantoin and their main hydroxylated metabolites by nitrogen-selective gas chromatography.

Caffeine, Theophylline and Theobromine Determinations in Serum, Saliva and Spinal Fluid

A rapid method for simultaneous determination of caffeine and theophylline from the serum, saliva, or spinal fluid of neonates was developed. Fifty-microUter samples were extracted and analyzed by high-pressure liquid chromatography (HPLC) at a low accurately detectable limit of 0.1 mglUter. The sample preparation time was about 40 minutes. Instrumental analysis was performed in less than 10 minutes. Extraction efficiency from repeated analyses was determined to be 95  A precolumn was used to Increase the life of the analytical column. The EMIT-aad| method was compared to HPLC analysis and found to be less efficient.

Analyses of drugs and chemicals by infrared absorption spectroscopy. VI. Rapid simultaneous determination of aminopyrine and isopropylantipyrine in their preparations

A rapid method for simultaneous determination of aminopyrine and isopropylantipyrine in their pharmaceutical preparations has been devised by using infrared absorption spectroscopy.These two compounds are separated from phenacetine and caffeine by the use of carbon disulfide as a solvent. The key bands used for aminopyrine and isopropylantipyrine are 10.48 and 9.95μ, respectively, and these two components can be determined without interference of other components by the use of two available base lines. The results obtained by analysing standard mixed samples indicated that the method gave satisfactory results.

Rapid Method for Simultaneous Determination of Sulfur and Phosphorus in Petroleum Products

Rapid Method for Simultaneous Determination of Sulfur and Phosphorus in Petroleum Products