scholarly journals Influences of Oxygen Concentration on the Determination of Methane Associated with Hot Springs, with a Catalytic Combustion Gas Detector and a Gas Chromatograph

2010 ◽  
Vol 59 (2) ◽  
pp. 131-136
Author(s):  
Miho Yano ◽  
Tatsuhiko Kawamoto
1983 ◽  
Vol 66 (6) ◽  
pp. 1528-1531 ◽  
Author(s):  
Hiroshi Nakanishi

Abstract A gas chromatographic procedure is described for determining monosodium glutamate (MSG) in several types of food. A sample is extracted with acetone- water (1 + 1). Acetone is evaporated and an aliquot of the extract is buffered with 1M NH4OH-1M NH4CI pH 9 solution, and chromatographed directly on a column of QAE Sephadex A-25 that has been pretreated with the same buffer. MSG is eluted with 0.1N HC1, and a portion of the eluate is evaporated to dryness and reacted with dimethylformamide( DMF)-dimethylacetal to form the glutamic acid derivative, which is injected into a gas chromatograph and measured by flame ionization detection. Recoveries of MSG from sample fortified at 5-500 mg ranged from 92.8 to 100%.


2021 ◽  
Vol 11 (9) ◽  
pp. 3916
Author(s):  
Marta Wiśniewska ◽  
Andrzej Kulig ◽  
Krystyna Lelicińska-Serafin

Municipal waste treatment plants are an important element of the urban area infrastructure, but also, they are a potential source of odour nuisance. Odour impact from municipal waste processing plants raises social concerns regarding the well-being of employees operating the plants and residents of nearby areas. Chemical methods involve the determination of the quantitative composition of compounds comprising odour. These methods are less costly than olfactometry, and their efficiency is not dependent on human response. The relationship between the concentration of a single odorant and its odour threshold (OT) is determined by the odour activity value (OAV) parameter. The research involved the application of a multi-gas detector, MultiRae Pro. Measurements by means of the device were conducted at three municipal waste biogas plants located in Poland. In this paper we describe the results obtained when using a detector during the technological processes, the unitary procedures conducted at the plants, and the technological regime. The determination of these relationships could be useful in the development of odour nuisance minimization procedures at treatment plants and the adjustment to them. This is of paramount importance from the viewpoint of the safety and hygiene of the employees operating the installations and the comfort of residents in the areas surrounding biogas plants. Monitoring of expressed odorant emissions allows the course of technological processes and conducted unit operations to be controlled.


1983 ◽  
Vol 55 (6) ◽  
pp. 889-892 ◽  
Author(s):  
John H. Phillips ◽  
Robert J. Coraor ◽  
Steven R. Prescott

Author(s):  
G.P. Morie ◽  
C.H. Sloan

AbstractA gas chromatographic method was developed for the determination of N-nitrosodimethylamine (NDMA) in cigarette smoke. The NDMA in the smoke of 200 cigarettes was trapped in a solution of sodium hydroxide and separated from most of the smoke components by distillation from acidic and basic solutions. The aqueous solution was extracted for 8 hr. into ethyl ether in a Dean Stark apparatus. To concentrate the solution of NDMA, the ether was distilled until only 5 ml of the solution remained. An aliquot of this solution was analysed by means of a gas chromatograph equipped with a 200-ft. glass capillary column coated with Carbowax 20-M poly(ethylene glycoI). An alkali metal flame ionization detector with a selectivity of 10*/1 for nitrogen compounds to normal hydrocarbons was used. Small amounts (2 ng) of nitrosamines in the presence of large amounts of other compounds were easily detected. N-nitrosodimethylamine-C


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