Rubidium Sulfate Flame Detector: Modification of Flame Ionization Detectors, Parameter Characteristics, and Regions of Response of the Flame for Phosphorus Compounds

1970 ◽  
Vol 53 (6) ◽  
pp. 1129-1136
Author(s):  
Hiroko K Deloach ◽  
Delbert D Hemphill
Keyword(s):  
Phosphorus Compounds ◽  
Response Level ◽  
Detection Systems ◽  
Flame Ionization ◽  
Platinum Anode ◽  
Response Profile ◽  
Flame Detector ◽  
Rubidium Sulfate ◽  
Ionization Detectors ◽  
Made In

Abstract To obtain a reliable alkali-flame detector with a rubidium sulfate source, commercial detection systems were modified. Improvements were made in Barber-Colman Model 5121 FID and Varian Aerograph Model 1200 FID systems to decrease operational difficulties and detection inadequacies. Equipped with a rubidium sulfate alkali source and an adjustable platinum anode, the modified Barber- Colman FID was used to study the phosphorus response of various regions in the flame. Flame configuration, affected by flow rates of gases, influences not only the absolute response level but also the response profile as a function of the anode height. Consequently, the region of maximum response was altered markedly by the flame configuration. The region of the flame with maximum ion population is located within the area immediately surrounding the outside of the flame rather than in the flame.

Gas Chromatography of Pesticides—Improvements in the Use of Special Ionization Detection Systems

1966 ◽  
Vol 49 (1) ◽  
pp. 8-21
Author(s):  
L Giuffrida ◽  
N F Ives ◽  
D C Bostwick
Keyword(s):  
Electron Capture ◽  
Detection System ◽  
Organophosphorus Pesticides ◽  
Phosphorus Compounds ◽  
Detection Systems ◽  
Flame Ionization ◽  
Hydrogen Flame ◽  
Dual Analysis ◽  
Organohalogen Compounds ◽  
Increased Sensitivity

Abstract The operating parameters for electron capture and flame ionization detectors are discussed, and the effects of varying each are described. Investigation of the detection of organophosphorus pesticides by a hydrogen flame burning in an atmosphere of alkali metal salts has resulted in increased sensitivity and complete specificity. With the use of potassium salts, sensitivity for phosphorus compounds equals that of the electron capture detector for chlorinated hydrocarbon pesticides. A detection system using both detectors to obtain a dual analysis simultaneously is described. Specificity is achieved with certain halogen salts (KCl, KBr, RbCl) which suppress the minor enhanced response by the modified flame detector to organohalogen compounds.

Nanomechanical Biosensor Using Polymer Membranes

2004 ◽  
Author(s):  
Srinath Satyanarayana ◽  
Daniel T. McCormick ◽  
Arun Majumdar
Keyword(s):  
Surface Stress ◽  
A Priori ◽  
Detection Systems ◽  
Stress Sensors ◽  
Design Flexibility ◽  
High Elasticity ◽  
Sensor Geometry ◽  
Specific Reactions ◽  
Higher Sensitivity ◽  
Made In

In recent years several surface stress sensors based on microcantilevers have been developed for biosensing [1–4]. Since these sensors are made using standard microfabrication processes, they can be easily made in an array format, making them suitable for high-throughput multiplexed analysis. Specific reactions occurring on one surface (enabled by selective modification of the surface a priori) of the sensor element change the surface stress, which in turn causes the sensor to deflect. The magnitude and the rate of deflection are then used to study the reaction. The microcantilevers in these sensors are usually fabricated using material like silicon and its oxides or nitrides. The high elasticity modulus of these materials places limitations on the sensitivity and sensor geometry. Alternately polymers, which have a much lower elastic modulus when compared to silicon or its derivatives, offers greater design flexibility, i.e. allow the exploration of innovative sensor configurations that can have higher sensitivity and at the same time are suitable for integration with microfluidics and electrical detection systems.

SYMPOSIUM ON URINARY CONSTITUENTS OF LOW MOLECULAR WEIGHT Session III

1968 ◽  
Vol 14 (6) ◽  
pp. 491-512 ◽  
Author(s):  
Ian E Bush
Keyword(s):  
Biochemical Analysis ◽  
General System ◽  
Low Molecular Weight ◽  
Gas Liquid Chromatography ◽  
Double Blind ◽  
Flame Ionization ◽  
Routine Work ◽  
Central Apparatus ◽  
Ionization Detectors ◽  
Blind Trials

Abstract A summary of the strategy and progress in devising a general system of biochemical analysis based on the direct photometry, or "scanning" of thin-media chromatograms is presented. Recent results suggest that the method is as precise and as accurate as other types of quantitative chromatography. It is capable of reasonably easy adoption by workers previously unfamiliar with the basic technic and apparatus. It has been subjected to more rigorous quality control by blind and double-blind trials concurrent with ordinary routine work than is usual, and has passed these tests adequately. Data processing by a small, relatively inexpensive digital computer is capable of handling the data produced by the central apparatus of the method. The sensitivity of newer instruments using well-established fluorescence reactions compares very favorably with that of flame-ionization detectors in gas-liquid chromatography but not with the electron-capture detector as yet.

A Pure Rubidium/Quartz Source for Alkali Flame Ionization Detectors

1978 ◽  
Vol 16 (1) ◽  
pp. 8-11 ◽  
Author(s):  
R. Greenhalgh ◽  
J. Muller ◽  
W. A. Aue
Keyword(s):  
Flame Ionization ◽  
Ionization Detectors

scholarly journals Seasonal and Circadian Rhythm of a 1,8-Cineole Chemotype Essential Oil of Calycolpus goetheanus From Marajó Island, Brazilian Amazon

2020 ◽  
Vol 15 (6) ◽  
pp. 1934578X2093305
Author(s):  
Edimara L. dos Santos ◽  
Ananda M. Lima ◽  
Vilmara Fabrícia dos S. Moura ◽  
William N. Setzer ◽  
Joyce Kelly R. da Silva ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Chemical Composition ◽  
Rainy Season ◽  
Brazilian Amazon ◽  
Dry Season ◽  
Chemical Compositions ◽  
Flame Ionization ◽  
Group I ◽  
Marajó Island ◽  
Ionization Detectors

Chemical composition of essential oils (EOs) of Calycolpus genus have been reported in the literature. However, there is only 1 report about volatile profile from Calycolpus goetheanus. This work aims to evaluate the seasonal and circadian influences on EO composition and yield of C. goetheanus collected in Marajó Island, Brazilian Amazon. For the circadian study, the leaves were collected in January (rainy season) and July (dry season) every 3 hours during a period of 15 hours. The EOs were obtained by hydrodistillation and their chemical compositions analyzed by gas chromatography coupled to mass spectrometry and flame ionization detectors. The major compound identified in all EO samples was 1,8-cineole with amounts ranged from 14.4% (January, 6 am) to 33.0% (July, 3 pm). The highest average of 1,8-cineole was obtained during circadian study of the dry season (25.5% ± 5.8%) and the lowest during the circadian study of the rainy season (15.6% ± 1.5%). The multivariate analysis grouped the samples into 2 different groups: Group I characterized by the lowest amounts of 1,8-cineole (16.0%-18.7%), and Group II characterized by a higher content of 1,8-cineole (24.0%-33.0%). The oil yield and chemical composition did not show relationship with climate parameters (solar radiation, humidity, and temperature). Therefore, there was only quantitative variability in the EOs compositions during the circadian rhythm evaluated on dry and rainy seasons.

Experimental Study of Gas Dispersion over Complex Terrain

2016 ◽  
Vol 821 ◽  
pp. 85-90 ◽  
Author(s):  
Petr Michálek ◽  
David Zacho
Keyword(s):  
Experimental Study ◽  
Complex Terrain ◽  
Dispersion Model ◽  
Concentration Field ◽  
Ground Level ◽  
Gas Emission ◽  
Gas Dispersion ◽  
Terrain Model ◽  
Flame Ionization ◽  
Ionization Detectors

Experimental study of gas dispersion over complex terrain model was performed in VZLU Prague. A complex terrain model was mounted into a boundary layer wind tunnel and equipped with ground-level gas emission source. Concentration field of the emitted gas was measured using comb suction probe and flame ionization detectors. The results will serve for verification and validation of a new computational dispersion model.

Gas Chromatographic Detection of D-( - )-2,3-Butanediol and Butyric Acid Produced by Sporeformers in Cream-Style Corn and Canned Beef Noodle Soup: Collaborative Study

1985 ◽  
Vol 68 (4) ◽  
pp. 626-631
Author(s):  
Mary L Schafer ◽  
James T Peeler ◽  
Joe G Bradshaw ◽  
Cleo H Hamilton ◽  
Ruth B Carver
Keyword(s):  
Butyric Acid ◽  
Volatile Fatty Acids ◽  
Collaborative Study ◽  
Bacillus Species ◽  
Flame Ionization ◽  
Chromatographic Detection ◽  
Liquid Portion ◽  
Gas Chromatographic Method ◽  
Negative Controls ◽  
Ionization Detectors

Abstract A gas chromatographic method that identifies sporeformers as the cause of spoilage in swollen cans of low-acid foods was collaboratively studied in 2 stages. Two organic compounds produced by sporeformers, D-( — )-2,3-butanediol and butyric acid, are measured in the upper phase after centrifugation of the liquid portion of the can contents. Each sample is assayed on 2 packed columns designed for the assay of aqueous solutions of volatile fatty acids, using flame ionization detectors. For study 1,16 duplicate inoculated cans of cream-style corn and beef noodle soup were sent to 9 collaborators. For study 2, 7 collaborators received 11 duplicate inoculated cans of the 2 foods. Duplicate uninoculated cans of each food served as negative controls. The inocula were 6 sporeforming organisms (4 Clostridium and 2 gas-forming Bacillus species) and 2 nonsporeformers. After the deletion of marginal samples, the percentages of correctly identified sporeformers and nonsporeformers in beef noodle soup were 83 (110/132) and 90 (54/60), respectively; corresponding percentages for cream-style corn were 80 (98/123) and 100 (35/35). The method has been adopted official first action.

Flame ionization detectors

1963 ◽  
Vol 10 ◽  
pp. 294-302 ◽  
Author(s):  
J. Middlehurst ◽  
B. Kennett
Keyword(s):  
Flame Ionization ◽  
Ionization Detectors

Cold Engine Transient Fuel Control Experiments in a Port Fuel Injected CFR Engine

2007 ◽  
Author(s):  
Leonard J. Hamilton ◽  
Jim S. Cowart
Keyword(s):  
Steady State ◽  
Fuel Mixture ◽  
Operating Regime ◽  
Warm Up ◽  
Flame Ionization ◽  
Mixture Preparation ◽  
Steady State Operation ◽  
Fuel Vaporization ◽  
Unburned Hydrocarbons ◽  
Ionization Detectors

Air-fuel mixture preparation is particularly challenging during cold engine throttle transients due to poor fuel vaporization and transport delays in port fuel injected (PFI) engines. In this study, a PFI Cooperative Fuels Research engine is used to evaluate torque and measure in cylinder and exhaust CO, CO2 and unburned hydrocarbons during throttle transients at various early stages of engine warm-up. Fast flame ionization detectors and non-dispersive infra-red fast CO and CO2 detectors are used to provide detailed cycle-by-cycle analysis. Torque after cold throttle transients is found to be comparable to steady state torque due to allowable spark advance. However, cold transients produce up to 4 times the unburned hydrocarbons when compared to steady state operation. Finally, the x-tau fuel control model is evaluated in this challenging operating regime and is found to provide poor transient fuel control due to excessive fueling.

Occurrence and Distribution of 2-Butanol, 1-Butanol, 1-Pentanol, and 1-Hexanol in Distilled Alcoholic Beverages

1977 ◽  
Vol 60 (2) ◽  
pp. 297-301
Author(s):  
John H Barnett ◽  
Joanne R Einsmann
Keyword(s):  
Methyl Acetate ◽  
Alcoholic Beverage ◽  
Isoamyl Alcohol ◽  
Isoamyl Acetate ◽  
Alcoholic Beverages ◽  
Chromatographic System ◽  
Isobutyl Alcohol ◽  
Flame Ionization ◽  
Liquid Chromatographic ◽  
Ionization Detectors

Abstract A survey was made of the distribution of 2-butanol, 1-butanol, 1-pentanol, and 1-hexanol in 198 brands of distilled alcoholic beverages. The principal concern of this study was to determine the applicability of any of the 4 congeners studied to be used as parameters in alcoholic beverage characterization. 1-Pentanol has very narrow use, because it occurred significantly in only 1 brand. 1-Butanol and 2-butanol show intermediate possibilities. 1-Hexanol had wide distributions, and was judged best of the 4 as a parameter. A distinction was shown between 2 brands, similar in other parameters, on the basis of the 1-hexanol content of each. In a 7-year survey, 1-hexanol was consistently characteristic for a single brand. All analyses were done using dual columns, dual flame ionization detectors in a gas-liquid chromatographic system, employing temperature programming from 50 to 150°C. Columns contained 2% Carbowax 20M, 3% Carbowax 1500, and 1% mineral oil on 45—60 mesh Chromosorb G. In addition to the 4 congeners mentioned, the following are also separated by this procedure: acetaldehyde, methyl acetate, ethyl acetate, methanol, 1-propanol, isobutyl alcohol, isoamyl acetate, isoamyl alcohol, hexyl acetate, ethyl caprylate, and 2-furfural.

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