SPECIFIC METHOD FOR THE DET
OZONE IN THE ATMOSPHERE
Sham L. Sachdev, et al
Louisiana State University
PB-213 019
R MI NAT] ON OF
Prepared for:
Environmental Protection Agency
January 1972
DISTRIBUTED BY:
National Technical Information Service
U. S. DEPARTMENT OF COMMERCE
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twBLIOCRAPHIC DATA
SHEET
I. Ki port No.
EFA-R3-72-015
PB
I. Till.- Tnd SulintU
Specific Method for the Determination of Ozone in
the Atmosphere
7. Author(s)
Sham L. Sachdev, J. P. Lodge, Jr., £ Philip if. West
9. Performing Organization Name and Address
Coates Chemical Laboratories
Louisiana State University
Baton Rouge, Louisiana 70803
12. Sponsoring Organisation Name and Address
ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, N. C. 27711
5* K<;port I)at'.
January 1972
6.
8« Performing Organization Kept.
No.
10. Projcct/'Task/Work Unit No.
11. ("omrac t /Grant No.
CPA 22-69-100
13. ! ype ol Report ,t Period
C overed
i-' i n a 1
14.
15. Supplementary Notes
16. Abstracts A description is given of work undertaken to develop a simple,
specific, and reliable method for ozone. Reactions of ozone with
several 1-alkenes were studied at room temperature (25°). Eugenol
(4-Allyl-2-methoxy phenol), when reacted with ozone, was found to
produce relatively large amounts of formaldehyde as compared to other
1-alkenes tested. The method described was compared with alkaline
iodide method for the determination of various concentrations of ozone
in the range of 0.05 to 2.0 ppm. The reactions of ozone with eugenol
were found to yield stoichiometric amounts of formaldehyde. Hydrogen
peroxide, peracetic acid, sulfur dioxide and various reducing agents
commonly present in the air, do not interfere with the method. For-
maldehyde when present in the air, must be determined simultaneously
and the concentration of formaldehyde subtracted from that of the ozone.
Any formaldehyde monitoring equipment can be easily adopted for the
- - -" — -r r .. _- - - "^-m-- J
17. Key Words and Document Analysis. 17a. Descriptors
Air Pollution Chemical Reactions
Ozone
Mea&urement
Chemical Analysis
Formaldehyde
Alkene Compounds
Sampling
17b. Ideniit icrs/Open-i'.nded 1 erms
4-ally1-2-methoxy phenol (eugenol)
determination of ozone.
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EPA-R3-72-015
SPECIFIC METHOD FOR THE
DETERMINATION OF OZONE IN THE ATMOSPHERE
BY
Sham L. Sachdev, J. P. Lodge, Jr.
and
Philip W. West
Coates Chemical Laboratories
Louisiana State University
Baton Rouge, Louisiana
Ozone is the principal oxidant in the photochemical smog, and a
detailed study of ozone toxicity in man has been reported by Griswold,
et al. (Griswold, 1957)- It *s also considered to be the most damaging
of all air pollutants affecting vegetation (Heggestad, 1969). The
natural occurence of ozone and its formation in the urban atmospheres
is well known (Renzetti, 1959)-
Published methods for the determination of ozone involve a variety of
analytical techniques such as chemical oxidation (Brewer and Milford, I960;
Byers and Saltzman, 1959j Haagen-Smit and Brunelle, 195®? Saltzman and
Gilbert, 1959), absorption of ultraviolet light (Cohen, et al., 1967;
Renzetti and Romanowsky, 1959j Stair, et al., 195^)., catalytic decomposition
(McCuJJy, t>i aJ., 196!; Olmcr, 1959), flit-miluminescence or fluorescence
(Regner, I960; Watanbe and Nakodoi, 1966), and cleavage of an olefinic
bond (Bradley and Haagen-Smit, 1951; Bravo and Lodge, 1964; Bufalini, 1968;
Hauscr and Bradley, 1966). Most ol these methods are not specific for ozone,
and they are generally used for determinations of total oxidants. Others which
are specific suffer the disadvantage that they are very complicated or require
*:requent calibration. Obviously the need for a simple, specific, and reliable
method for ozone is becoming critical.
•^National Center for Atmospheric Research, Boulder, Colorado
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The method presented here is based on the reaction of ozone with
^-allyl-2-methoxy phenol (eugenol). This reaction has been found to be
specific. Moreover, the stoichiometry of the reaction involves the
formation of one molecule of formaldehyde for each molecule of ozone
consumed. Formaldehyde formed is determined by a slight modification of
£he West-Gaeke procedure (1965) for sulfur dioxide.
EXPERIMENTAL
APPARATUS:
Gas samplers (described by Wartburg, Pate and Lodge, 1969), midget
impingers (MSA Catalog No. 46984).
Air flow meters (Fisher and Porter Co., Catalog No. 4-50-015).
Dyna-vac pump (Cole-Parmer, Catalog No. 7064)•
Beckman D B cpectrophotomctcr
REAGENTS:
Para-rosaniline hydrochloride (Fisher Scientific Co., Catalog
No. 42,500).
Mercuric chloride, sodium chloride, sodium hydroxide, potassium iodide,
sulfamic acid and standard formaldehyde solution (1000 mg/l).
Sodium tetrachloromercurate(ll) solution: This solution was prepared
by dissolving 1J.6 g of mercuric chloride and 5-8 g of sodium chloride
per liter of distilled water.
Para-rosaniline reagent:
Prepared by dissolving 0.16 g of para-rosaniline hydrochloric in 24 ml
of concentrated HC1, then diluting to 100 ml with distilled water.
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Alkaline iodide solution:
Ten grams of KI and 40 g of NaOH were dissolved per liter of water.
Acidifying reagent:
Five grains of sulfamic acid were dissolved in 100 ml of water, then
84 ml of 85^ phosphoric acid were added and the mixture was made up to
200 ml.
Preparation of ozonized air:
Samples of ozonized air were prepared by passing prepurified air through
a brown glass aspirator bottle of 5 liter capacity in which a germicidal
lamp (k Watt, General Electric) was fixed. The mouth of the bottle was
sealed with a cork through which passed the leads of the lamp and an outlet
tube as shown in Figure I. After initial assembly of the ozonation apparatus,
the lamp was kept on for a week so that it could generate enough ozone to
react with any of the organic matter that might be present in the aspirator.
Subsequently, before analyses, the lamp was turned on every morning at least
an hour before any samples were ozonized. Ozone concentrations could be
established at any desired concentration between 0.5 and 10 ppm by adjusting
the flew of air through the aspirator. Lower concentrations (down to 0.05 PPm ^3)
were obtained by partially covering the lamp with aluminum foil and equilibrating
the system for ten days to allow for any reaction of ozone with aluminum foil.
Sampling Procedure:
The sampling equipment was set up as shown in Figure I. The gas samplers
shown were obtained from the National Center for Atmospheric Research,
Boulder, Colorado. Alternatively, midget impingers were also found to be
satisfactory. Two sampling bubblers were used in series. One was used as an
impinger in which air containing ozone was directed upon the surface of eugenol
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placed in the container; the second, containing 10 ml of distilled water,
was used as an absorber for formaldehyde. Air in the first impinger was
passed through an orifice of 1 mm diameter at a rate of 2 1/m. The jet
velocity has been estimated to be Mv m/sec. With 1 ml of eugenol in the
tube, the spacing between the orifice tip and the surface of the eugenol
was 5 nrn. In the second bubbler the orifice may be replaced by a frit
which must be completely immersed in the water used for absorbing the for-
maldehyde.
Purification of eugenol:
Eugenol, as well as all other 1-alkenes tried, was found to contain
formaldehyde as an impurity, probably this results from the exposure of the
compounds to atmospheric ozone. Each olefin was purified just before use,
by passing it through a 3 inch colume of pure, dry sodium sulfite crystals.
RESULTS AND DISCUSSION
A study of ozonolysis of various 1-alkenes was undertaken to develop
a reliable method for the determination of ozone. A similar attempt was
made by Hauser and Bradley (1966) who reacted ozone with various 1-alkenes
directly in solvents such as ethyl acetate, acetic acid, dimethyl sulfoxide,
etc. They found formaldehyde in some of the ozonized mixtures but discontinued
studies along this line because of water insolubility of 1-alkenes and high
degree of color formed in the blank determinations.
Because of the high reactivity of ozone, it was decided that the direct
passage of ozone-containing air samples into 1-alkenes and then through a
second bubbler containing 10 ml of distilled water would be the most reliable
approach. The formaldehyde, which has a low boiling point (-21°C) and a
very low solubility in alkenes, was expected to be collected in the second
bubbler. Air containing known concentrations of ozone was reacted with several
organic compounds containing the -CH = CH2 group and the formaldehyde formed
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was collected and determined by the metho,. of Lyles et al., (1965). The
results are shown in Table I. Impinging of air on the alkene was found to
be as effective as bubbling for the production of formaldehyde. In the case of
bubbling, however, more alkenes were carried out over the second container
and had to be removed before taking final spectrophotometric readings.
Determination of formaIc'ehyde:
Two reliable methods are available for the determination of formaldehyde:
(1) The method developed by Lyles, et al., (19&5) and (2) The chromotropic
acid method (West, et al., 1956; Altshuller, et. al., 1961). The latter
method was found unsuitable because some vapors of eugenol were carried into
the air along with the formaldehyde formed and interfered. The method of
Lyles, et al., which is based on a slight modification of the West-Gaeke
method for sulfur dioxide, has been found to be simple, reliable, and
satisfactory for the determination of formaldehyde formed by the reaction of
ozone and eugenol.
Stoichiometry of the reaction:
The ozone concentration in an air containing about 2 ppm. of ozone was
determined by the formaldehyde method, the neuLral iodide method and the
alkaline iodide method. The same ozonized air under exactly similar conditions
was used in all three determinations. The following results were obtained:
Method Ozone Concentration(ppm)
Neutral iodide 2.J5
Alkaline iodide 1«55
Eugenol-formaldehyde 1-50
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A recent report on the stoichiometry of the iodide method, by
Boyd, et al., (1970), indicated that the alkaline iodide method yields
one iodine molecule for every molecule of ozone reacted, whereas the neutral
iodide method actually yields 1-5^ molecules of iodine per molecule of ozone
reacted. Results of the present study are in complete agreement with the
results of Boyd, et al., although our method for the determination of ozone
is completely different.
Determinations of ozone at different concentration levels:
Ozone was determined in several samples of air containing ozone in the
range of 0.05 to 2.0 ppm. Each concentration level was determined three
times by the alkaline iodide method as well as by the eugenol-formaldehyde
procedure. Results are given in Table II.
The eugenol-formaldehyde method yields results comparable to those obtained
by the alkaline iodide method of Byers and Saltzman (1959)> at &H concentrations
within the range of (0.05 to 2 ppm). Since it is unlikely that ozone
will exist in ordinary atmospheres at concentrations greater than 2.0 ppm,
determinations of higher concentrations were not extensively investigated.
A few concentraLions in the range of 2-5 ppm of ozone were determined by the
eugenol-formaldehyde procedure, but no comparison was made with the iodide
method.
Sensitivity of the method:
The sensitivity of the method is exactly the same as that for the formaldehyde
method of Lyles, et al., (1965); since ozone reacts to produce formaldehyde in
a 1/1 mole ratio. An ozone concentration of 0.02 ppm can be easily determined
by sampling the air for kO minutes at a rate of two liters per minute.
Selectivity of the method:
The eugenol-formaldehyde method described seems to be specific for ozone.
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However, it is important that appropriate correction be made for the formaldehyde
present in the ambient atmosphere. This presents no problem because the
formaldehyde background level can be determined as a check by simply
by-passing the first (eugenol) impinger and collecting and determining the
formaldehyde in a separate bubbler.
Interference effects of hydrogen peroxide (3$) and peracetic acid were
examined by spraying the two solutions into the air being sampled. Neither
of these compounds produced any formaldehyde when reacted with eugenol.
Sulfur dioxide and other reducing agents present in the air were not observed
to interfere with the ozone determination.
Field studies:
The method has been tested for on-site determinations of ozone. These
studies indicate that the method would be quite suitable for field studies
(Lyles, 1970)' Any formaldehyde monitoring equipment can be easily adapted
for monitoring ozone. One need only connect to the formaldehyde monitor
a midget impinger containing 1 ml of eugenol to convert it to an ozone monitor.
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ABSTRACT
A simple, sensitive and specific method for the determination
of ozone in the atmosphere is described. Reactions of ozone with
Several 1-alkenes were studied at room temperature (25°). Eugenol
(ty-Allyl-2-methoxy phenol), when reacted with ozone, was found to
produce, relatively large amounts of formaldehyde as compared to other
1-alkenes tested. The method described was compared with alkaline
iodide method for the determination of various concentrations of ozone
in the range of 0.05 to 2.0 ppm. The reactionsof ozone with eugenol
were found to yield stoichiometric amounts of formaldehyde. Hydrogen
peroxide, peracetic acid, sulfur dioxide and various reducing agents
commonly present in the air, do not interfer with the method. For-
maldehyde when present in the air, must be determined simultaneously and
the concentration of formaldehyde subtracted from that of the ozone.
Any formaldehyde monitoring equipment can be easily adopted for the
determination of ozone.
N.
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LITERATURE CITE!
1. Altshuller, A. P., Miller, D, L. and Sleva, S. F., Anal. Chem. ,
22, 621 (1961).
2. Boyd, A. W., Willis, C., arid Cyr, R., Anal. Chem., 42, 670 (1970).
3. Bradley, C. E. and Haagen-smi t, /., J., Rybbier Chem. Tech., 24
750 (1951).
4. Bravo, H. A. and Lodge, J. P., Jr., Anal. Chem. 36, 76! (1964).
5. Brewer, A. W. and Milford, J. R., J?r_oc. Roy. Soc. London Ser. A.,
256. 470 (I960).
6. Bufalini, J. J., Eny. Sci. and Tech., 2, 703 (1968).
7. Byers, D. H. and Saltzman, B. E., Adv. Chem. Ser., 21, 93 (1959).
8. Cohen, I, R., Purcell, T. C. and Altshuller, A. P., Eny. Sci. and Tech.,
1, 247 (1967).
9. Griswold, S. S., L0 A, Chambers and H. L. Motley, AMA Arch Ind. Health,
!§, 108 (1957).
10. Haagen-smit, A. J. and Burnelle, M. F., Interne J. Air a.nd. Water Pollution,
L 59 (1958).
11. Hauser, T. A. and Bradley, D. W., Anal. Chem. 3_8, 1529 (1966).
12. Heggestad, H. E., J. Air PoU. Contr. Assoc^ !£, 424 (1969).
13. Lyles, G. R., (Private Communication).
14. Lyles, G. R., Dowling, F. B. and Blanchard, V. J., Air Poll. Contr. Assoc.,
106 (1965).
15. McCully, C. R., Roester, J. E., Gordon, E. S., Van Scoyoc, J. N., and
Carrigan, R. A., Ire. Trans, ln_str.,, _1^10^ 89 (1961).
16. Mittler, S0, King, M. and Burkhard;., B«, Adv. Chem. Ser., 21, 344 (1959).
17. Olmer, F. Jo, Adv. Chem. Ser., £!_ 87 (1959).
18. Kegner, V. H., J. Geophys , Res., 65^ 3975 (I960).
19. Renzetti, N. A., Adv. Chem. Ser., 21, 230 (1959).
20. Renzetti, N. A. and Romanowsky, J. C., J. Air Poll. Control Assoc0,
6, 379 (1959).
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21. Saltzman, B. E. and Gilbert, N., Am. lad. Hjg. Assoc. J., 20, 519 (1959)
22. Stair, R., Bagg, T. C. and Johnston, R. 6., J. Res. Natl. Bur. S td . ,
133
23. tfataiiabe, H. and Nakodoi, T., J. Air Poll. Contr. Assoc.. 16, 614 (1966)
. Wartburg, A. F., Pate, J. B. and Lodge, J. P., Jr., Env. Sci. and
., 3, 76f (1969).
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TAILS T
STUDY OF OZONOLYSIS OF VARIOUS 1-ALKENES
Sampling Rate 2 I/mm.
Sampling Time 5 nm"
Ozone concentration del.ernu.ped by neutral iodide
method. 2.2. ppm
Ozone concentration determined by alkaline iodide
method 1.5 ppm
Compound Used
1-Octene
1-Decene
1-Dodecene
Eugenol
3,4 Dimethoxyallyl
HCHO
obtaine
9
9
8
20
6
benzene
1)1 a I I y I |0il l.n l.nl r-. f,
Diallyi isophthaiate 6,^
Ozone Concentration
(Proposed Method PPM)
0.67
0.6?
0.60
1.5
O.it-5
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TABLE II
^Comparative Study of Eugenol-formaldehyde method and Alkaline
iodide method.
Ozone Concentration
Alkaline iodide
method
0.045
0.11
0.18
0.25
0.99
1.20
1.50
1.90
(pp»)*
Eugenol-formaldehyde
Method
0.050
0.10
0.17
0.25
0.92
1.15
1.1*5
1.80
^Results tabulated are averages of three samples.
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