Chromatographic Determination of Rubber in Plant Latexes

1956 ◽  
Vol 29 (3) ◽  
pp. 1026-1033 ◽  
Author(s):  
Dorado E. Bernal
Keyword(s):  
Partition Coefficients ◽  
Chromatographic Method ◽  
Rapid Determination ◽  
Chromatographic Determination ◽  
Partition Chromatography ◽  
Biological Cycle

Abstract Partition chromatography on paper makes possible the separation of rubber hydrocarbon from latex. This method offers a means which is both simple and rapid for determining the presence of rubber in plant latexes and for the subsequent estimation of its percentage in a given latex. The method also gives a fraction which is composed of the nonrubber components. In addition to this, the method makes possible a comparison of the partition coefficients of rubber hydrocarbon isolated from latexes of different plants. Experiments are now in progress, the purpose of which is the application of the chromatographic method to the rapid determination of plant rubbers. By its simplicity, this method unquestionably has certain advantages in the identification of rubber in any particular flora and in studies of this hydrocarbon in its various phases of the biological cycle of the plant.

Gas Chromatographic Determination of N-Butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine and α,α,α-Trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine in Formulations

1971 ◽  
Vol 54 (3) ◽  
pp. 711-712
Author(s):  
Martha Fuzesi
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Electron Capture ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Electron Capture Detector ◽  
Reference Solution ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for the quantitative determination of N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-tolindine and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyI-p-toluidine herbicides in formulations. The sample is extracted with benzene, and equal amounts of sample and reference solution in the same concentration range are analyzed by gas chromatography, using an electron capture detector and an SE-30/Diatoport S column. The method has been applied successfully to laboratory-prepared and commercial samples.

Optimized liquid-chromatographic determination of metronidazole and its metabolites in plasma.

1984 ◽  
Vol 30 (5) ◽  
pp. 784-787 ◽  
Author(s):  
R A Gibson ◽  
L Lattanzio ◽  
H McGee
Keyword(s):  
Rapid Determination ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Detector Response ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
Wide Range ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Metronidazole and its known metabolites in plasma can be rapidly separated by a "high-pressure" liquid-chromatographic method that can also be adapted for rapid determination of tinidazole. Samples deproteinized with trichloroacetic acid (50 g/L final concentration) undergo isocratic separation on a reversed-phase C18 column eluted with an 8/92 (by vol) mixture of acetonitrile/KH2PO4 (5 mmol/L, pH 3.0). The method is sensitive, reliably detecting as little as 25 micrograms of metronidazole and (or) its metabolites per milliliter of plasma. The detector response varied linearly with concentration for all compounds tested over a wide range (25-500 micrograms/L). Within-day and between-day variation was generally less than 2.5% for all concentrations of all compounds tested. Various other antibiotics tested did not interfere.

scholarly journals Robustness evaluation of the chromatographic determination of verapamil hydrochloride

2017 ◽  
Author(s):  
L. S. Logoyda
Keyword(s):  
Analytical Methods ◽  
Mobile Phase ◽  
Chromatographic Method ◽  
Final Analysis ◽  
Chromatographic Determination ◽  
Validation Process ◽  
Verapamil Hydrochloride ◽  
A Value ◽  
Analytical Parameter

The aim of this study was the rubustness evaluation of the chromatographic determination of verapamil hydrochloride using Youden’s test.Methods: Youden’s test is a reliable method to evaluate the robustness of analytical methods, by means of an experiment design which involves seven analytical parameters combined in eight tests. In the present study, we assessed the robustness of a chromatographic method to quantify verapamil hydrochloride using Youden’s test. Hence, it was possible to determine the effect of each analytical parameter in the final analysis results. Youden’s test showed to be a simple and feasible procedure to evaluate the robustness of chromatographic methods.Results: Using the criteria of Youden’s test, the chromato­graphic method showed to be highly robust regarding the verapamil hydrochloride content, when variations in seven analytical parameters were introduced. The highest variation in the verapamil hydrochloride content was 0.26 %, when the concen­tration of triethylamine in the mobile phase was altered; a value considerably low and not significant in routine analyses.Conclusion: Youden’s test showed to be a reliable and useful tool for the robustness evaluation of the chromatographic method for verapamil hydrochloride quantitation. By means of this test, it was possible to evaluate the effect of seven analytical parameters in the final result of the analyses. Therefore, Youden’s test can be successfully applied for the ro­bustness evaluation in validation process of analytical methods by HPLC.

Gas Chromatographic Determination of Thiouracils in Feeds

1965 ◽  
Vol 48 (5) ◽  
pp. 908-911
Author(s):  
Arnaldo Fravolini ◽  
Alfredo Begliomini
Keyword(s):  
Chromatographic Separation ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Methyl Silicone ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method has been used to determine thiouracils added to feeds. The chromatographic separation is carried out on alkylated compounds. A column of SE-30 polymer methyl silicone was used. Recoveries averaged between 92 and 103%. The procedure is simple and brief.

scholarly journals Gas Chromatographic Determination of Chlorothalonil in Leaves and Roots of Scrophularia and in Soil

1996 ◽  
Vol 79 (2) ◽  
pp. 587-588 ◽  
Author(s):  
Lan Zhao ◽  
De-Fang Fan
Keyword(s):  
Electron Capture ◽  
Chromatographic Method ◽  
Detection Limits ◽  
Chromatographic Determination ◽  
Soil Samples ◽  
Florisil Column ◽  
Glass Column ◽  
Leaves And Roots ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for determination of chlorothalonil residues in leaves and roots of Scrophularia and in soil. Samples were extracted with acetone and cleaned up on a Florisil column. Chlorothalonil residues are chromatographed directly on a glass column of 1.5% OV-17 and 2% QF-1 coated on 80-100 mesh Chromosorb W (HP) support and measured with a 63Ni electron capture detector. Detection limits are 0.001 ppm for leaf, 0.005 ppm for root, and 0.001 ppm for soil.

Capillary Column Gas Chromatographic Determination of Trace Residues of the Herbicide Chlorsulfuron in Agricultural Runoff Water

1987 ◽  
Vol 70 (4) ◽  
pp. 745-748
Author(s):  
Uaz Ahmad
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Capillary Column ◽  
Methylene Chloride ◽  
Chromatographic Determination ◽  
Agricultural Runoff ◽  
Runoff Water ◽  
Florisil Column ◽  
Gas Chromatographic Method

Abstract A capillary column gas chromatographic method is described for determining parts-per-trillion (ppt) levels of chlorsulfuron in agricultural runoff water. The water sample is acidified with acetic acid and extracted with methylene chloride. The chlorsulfuron in the extract is derivatized to its monomethyl derivative. After Florisil column cleanup, the methylated chlorsulfuron is determined by electron-capture gas chromatography. Recovery of chlorsulfuron from fortified water samples is greater than 80%. Detection limit of the method is 25 ng chlorsulfuron/L water (25 ppt). There are 2 reaction sites on the chlorsulfuron molecule, both of which are susceptible to methylation leading to monomethyl chlorsulfuron and dimethyl chlorsulfuron. A procedure is described to methylate selectively the sulfonamide nitrogen of chlorsulfuron.

Gas Chromatographic Determination of Histapyrrodine Hydrochloride in Pharmaceutical Preparations

1986 ◽  
Vol 69 (4) ◽  
pp. 612-613
Author(s):  
Ramesh T Sane ◽  
Vipul J Doshi ◽  
Sanjay K Joshi ◽  
Vijay K Shastri ◽  
Dhananjay S Sapre ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Internal Standard ◽  
Pharmaceutical Preparations ◽  
Chromatographic Determination ◽  
Chlorpheniramine Maleate ◽  
Accuracy And Precision ◽  
Label Claim ◽  
Gas Chromatographic Method

Abstract A simple gas chromatographic method is described for the determination of histapyrrodine HC1 in marketed formulations. Chlorpheniramine maleate is used as the internal standard. The amount of histapyrrodine HC1 found by the proposed method averaged 19.91 mg/tablet, compared with the label claim of 20 mg/tablet. The method was statistically evaluated for accuracy and precision.

scholarly journals Gas Chromatographic Determination of Butylated Hydroxyanisole (BHA) and Butylated Hydroxytoluene (BHT) in Products Containing Capsaicinoids

1996 ◽  
Vol 79 (6) ◽  
pp. 1459-1462
Author(s):  
Bernard DeWitt ◽  
Gunnar Finne
Keyword(s):  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Butylated Hydroxytoluene ◽  
Butylated Hydroxyanisole ◽  
Liquid Chromatographic Method ◽  
Gas Chromatographic Method ◽  
Liquid Chromatographic

Abstract Because of interference by coeluting capsaicinoids, the commonly used liquid chromatographic method for determining butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in pepperoni and spice blends is not reliable. A gas chromatographic method is described that cleanly separates these antioxidants from interfering substances. Average recoveries of BHA and BHT from oleoresin spiked at 5 concentrations were 97.6 and 104.3%, respectively. From pepperoni spiked at 4 levels, average recoveries were 79.1 and 87.9%, respectively. The repeatability of the method when applied to 5 replicates of pepperoni toppings was 36.4 ± 1.1 ppm for BHA and 32.2 ± 0.8 ppm for BHT.

scholarly journals Gas Chromatographic Determination of Cyprodinil, Fludioxonil, Pyrimethanil, and Tebuconazole in Grapes, Must, and Wine

1997 ◽  
Vol 80 (4) ◽  
pp. 867-870 ◽  
Author(s):  
Paolo Cabras ◽  
Alberto Angioni ◽  
Vincenzo L Garau ◽  
Elizabeth V Minelli
Keyword(s):  
Chromatographic Method ◽  
High Selectivity ◽  
Chromatographic Determination ◽  
Mass Spectrometric ◽  
On Line ◽  
One Step ◽  
Low Sensitivity ◽  
Gas Chromatographic Method ◽  
Nitrogen Phosphorus

Abstract A rapid and simple gas chromatographic method for determinating cyprodinil, fludioxonil, pyrimethanil, and tebuconazole in grapes, must, and wine is described. An on-line microextraction method was used with a one-step extraction–partition procedure. Nitrogen–phosphorus and mass spectrometric detectors were used, because of their low sensitivity and high selectivity. Because of high selectivity of detector, no cleanup was necessary and the extract was concentrated 5 times. Recoveries from fortified grapes, must, and wine ranged from 93 to 110%. Limits of determination were 0.05 mg/kg for cyprodinil and pyrimethanil and 0.10 mg/kg for fludioxonil and tebuconazole.

Thin Layer Chromatographic Determination of Subsidiary Dyes in D&C Red No. 19 and D&C Red No. 37

1974 ◽  
Vol 57 (4) ◽  
pp. 961-962
Author(s):  
Sandra Bell
Keyword(s):  
Thin Layer ◽  
Silica Gel ◽  
Chromatographic Method ◽  
Chromatographic Determination

Abstract A thin layer chromatographic method is presented by which triethylrhodamine and other lower ethylated subsidiary colors are separated from D&C Red No. 19 and D&C Red No. 37. After removal from the plate, subsidiary dyes are extracted from silica gel C adsorbent and quantitated spectrophotometrically. Recoveries of 1, 2, and 5% of added triethylrhodamine ranged from 89 to 1 0 3% for D&C Red No. 19 and from 85 to 1 0 2% for D&C Red No. 37.

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