Chemistry: analytical and immunological testing – Oxygen containing – Carbonyl – ether – aldehyde or ketone containing
Patent
1998-04-05
2000-10-24
Warden, Sr., Robert J.
Chemistry: analytical and immunological testing
Oxygen containing
Carbonyl, ether, aldehyde or ketone containing
436128, 436166, 436167, 422 86, G01N 3122
Patent
active
061366080
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method for analyzing formaldehyde. More specifically, the invention relates to a method for analyzing formaldehyde in the ambient air by collecting formaldehyde gas and simply implementing an analysis of concentration thereof.
BACKGROUND ART
In recent years, it has been pointed out that toxic gas having harmful influence on a human body is discharged from various new building materials employed in dwelling houses and so forth. Formaldehyde gas has been listed as one of such toxic gases. Therefore, demand for collection of the formaldehyde gas in the ambient air and analysis of formaldehyde concentration is becoming greater.
The basic principle of the analysis of formaldehyde concentration well known in the art is as follows. Formaldehyde (HCHO) and AHMT (4-amino-3-hydrazino-5-mercapto-1,2,4-triazole) react under alkaline condition to form a product which indicates a red color when oxidized by KIO.sub.4 (potassium periodate). The density of this color development is in proportion to the concentration of the formaldehyde. Therefore, an analytical curve for performing the analysis of the unknown sample is prepared with respect to the relation between light transmittance (absorbance) in the vicinity of wavelength 550 nm and concentration of formaldehyde. The standard operating procedure is as follows. admixed, is measured by means of a pipette and filled into a glass vessel. added to the glass vessel. added to the glass vessel, and left for about 20 minutes while mixing. and added to the glass vessel. density of the resultant solution is measured by means of a colorimeter or a spectrophotometer. of which have different concentrations) containing a known amount of formaldehyde, respectively to prepare an analytical curve. derived by comparison with the analytical curve.
In addition, the formaldehyde concentration in the ambient air can be converted by the following equation,
However, according to the conventional method for analyzing formaldehyde set forth above, since the analyzing operation becomes extremely complicated, it is necessary to take the formaldehyde collected in the building site back to a location where an analyzing equipment is organized and implement the analysis of concentration. Therefore, the result of the analysis cannot be obtained at the site where the gas is collected, causing the possibility of delay in judgement and assessment. Meanwhile, the condition of the sample may also be changed by transportation of the collected sample, by transferring of vessels, and during storage until analysis implementation, all of which may create a situation in which accurate data cannot be obtained.
Furthermore, since a knowledge in chemistry is required for the calculation of the concentration, and since close attention becomes necessary upon handling the chemicals for analysis, analysis cannot be implemented except by a skilled person in chemical analysis. By this, problems such as long-time requirement and high cost by relying on an analyzing organization or the like are apt to arise.
DISCLOSURE OF THE INVENTION
The object of the present invention is to provide a method for analyzing formaldehyde in the ambient air, by which accurate measurement is enabled with simple operation, at low cost, without skill requirement, and within a short period of time in the building site.
A method for analyzing formaldehyde in the ambient air according to the present invention, comprises the steps of: filled with a given amount of 2N--KOH solution; leaving the reagent for a given amount of time; indication value thereof to a predetermined value; and setting the collecting vessel to the absorptiometer, and detecting formaldehyde concentration from the indication value of the absorptiometer.
In this case, it is preferable that the composition of the AHMT reagent may be AHMT:1%, and HCl:1 mol/liter, and the composition of the KIO.sub.4 reagent may be KIO.sub.4 :1% and KOH:0.25N.
A method for analyzing formaldehyde in the ambient air according to the present inve
REFERENCES:
patent: 4511658 (1985-04-01), Lambert et al.
patent: 5637505 (1997-06-01), Li et al.
Japanese Industrial Standard, "Methods for determination of formaldehyde in flue gas," K 0303-1993, UDC 543,274:547.281.1, month unavailable.
Dickinson et al., J. Chem. Soc. Perkins Trans. I, 10, pp. 975-979. month unknown 1975.
Durst et al., J. Chem. Educ., 55, p. 206, month unknown 1978.
Analytical Chemistry, vol. 46, No. 2 (1974) pp: 298-299, N.W. Jacobson and R.G. Dickinson, "Spectrometric Assay of Aldehydes as 6-Mercapto-3-substituted-s-triazolo(4, 3-b)-s-tetrazines".
Kawachi Takeshi
Moriya Masahiro
Sato Yasue
Obayashi Corporation
Olsen Kaj K.
Warden, Sr. Robert J.
LandOfFree
Method for determining formaldehyde present in air does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for determining formaldehyde present in air, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for determining formaldehyde present in air will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1962522