Determination of sample size for evaluation greenspace using the cumulative concentration levels of carbon dioxide in ambient air

This chapter contains information about application of the electronic nose type instruments to evaluation of ambient air odour quality connected with such sectors of human activity as municipal landfills or sewage treatment plants. The authors present potential sources of emission from these sectors, characterize the chemical compounds responsible for presence of unpleasant odours, describe the influence of those compounds on human health and related discomfort. Legal aspects pertaining to admissible odour concentration levels in selected countries are also presented. The chapter describes instrumental and sensory methods utilized for determination of odour concentration, odour intensity, or hedonic quality. The chemical sensors potentially and currently employed in the electronic nose type devices are also characterized. Moreover, the future prospects of application of the electronic nose instruments to evaluation of ambient air with respect to odour nuisance are discussed.

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Determination of Carbon Dioxide in Cucumber Brines

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/57.1.130 ◽

1974 ◽

Vol 57 (1) ◽

pp. 130-133 ◽

Cited By ~ 4

Author(s):

Henry P Fleming ◽

Roger L Thompson ◽

JOHN L Etchells

Keyword(s):

Carbon Dioxide ◽

Hydrochloric Acid ◽

Acid Solution ◽

Sample Size ◽

Sodium Hydroxide ◽

Small Sample Size ◽

Accurate Method ◽

Small Sample ◽

Small Vial

Abstract A simple, accurate method for determining carbon dioxide in fermenting cucumber brines is described. The method involves distillation of carbon dioxide from the acidified brine into standardized sodium hydroxide inside a closed jar. The sample is injected by a syringe and needle through a rubber serum stopper placed in the jar cap, into an acid solution. A small vial of sodium hydroxide placed inside the jar traps the carbon dioxide as it distills from the acidified solution. After being held in the jar 24 hr at 37°C, the vial is removed; the remaining base is titrated to the phenolphthalein end point with standardized hydrochloric acid. Advantages of the method include a limited working time, minimized loss of carbon dioxide during analysis, and a relatively small sample size.

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Determination of Chlordane and Chlorpyrifos in Ambient Air at Low Nanogram-Per-Cubic Meter Levels by Supercritical Fluid Extraction

Journal of AOAC International ◽

10.1093/jaoac/80.1.74 ◽

1997 ◽

Vol 80 (1) ◽

pp. 74-78 ◽

Cited By ~ 1

Author(s):

Kamal Swami ◽

Amarjit S Narang ◽

Rajinder S Narang

Keyword(s):

Carbon Dioxide ◽

Gas Chromatography ◽

Supercritical Fluid Extraction ◽

Supercritical Fluid ◽

Electron Capture ◽

Capillary Gas Chromatography ◽

Ambient Air ◽

Electron Capture Detection ◽

Hewlett Packard

Abstract A method for the determination of termiticides present in ambient air was simplified by modifying the extraction thimbles used in the Hewlett-Packard supercritical fluid extractor so they could be used for collection as well as extraction of termiticides. The method was applied to the determination of chlorpyrifos and technical chlordane. The termiticides were trapped on cartridges containing Florisil and foam plugs, extracted with carbon dioxide in the supercritical fluid extractor, and determined by capillary gas chromatography with electron capture detection. On the basis of a 20 m3 sample, detection limits were 0.1 ng/m3 for chlorpyrifos and 1.0 ng/m3 for technical chlordane.

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