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Abstract

The relative merits of five laser excitation schemes have been evaluated for photoionization spectrometry (PIS) measurements of NO in air. All five schemes utilize wavelengths near 215 nm, which correspond to excitation of rovibronic transitions in the A ²Σ⁺–X ²π_i (1,0) bands of NO. Photoionization of the excited NO molecules is accomplished by using wavelengths ranging from 215 to 1064 nm. Excitation spectra of the five PIS schemes reveal a significant enhancement when 355 nm radiation is used for photoionization. The enhancement is hypothesized to be related to a resonance or near-resonance ionization process for selected lines in the A ²Σ⁺–X ²π_1/2 band [specifically the R₁₁ + Q₂₁ (J″ = 8.5–12.5) lines and the P₂₁ + Q₁₁ (J” 9.5–10.5) lines] and the A ²Σ⁺–X ²π_3/2 band [specifically the R₁₂ + Q₂₂ (J” 8.5–12.5) lines and the P₂₂ + Q₁₂ (J” = 9.5–10.5) lines] of NO. Comparison measurements using all five schemes demonstrate that the highest sensitivity and highest signal-to-noise ratios are observed by using the 215 nm + 355 nm scheme, for which a limit of detection of 80 parts per trillion by volume for NO in air has been achieved.

Keywords

Photoionization NO Excitation scheme

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References

Letokhov

V. S.

, Laser Photoionization Spectroscopy (Academic Press, New York, 1987).

Simeonsson

J. B.

Elwood

S. A.

Niebes

Carter

and Peck

, Anal. Chim. Acta 393, 33 (1999).

Lee

S. H.

Hirokawa

Kajii

and Akimoto

, Rev. Sci. Instrum. 68, 2891 (1997).

Peng

Ledingham

K. W. D.

Marshall

and Singhal

R. P

, Analyst 120, 2537 (1995).

Simeonsson

J. B.

Lemire

G. W.

and Sausa

R. C

, Anal. Chem. 66, 2272 (1994).

Robie

D. C.

Buck

J. D.

and Bischel

W. K

, Appl. Opt. 29, 3961 (1990).

Simeonsson

J. B.

Lemire

G. W.

and Sausa

R. C

, Appl. Spectrosc. 47, 1907 (1993).

Marshall

Clark

Deas

R. M.

Kosmidis

Ledingham

K. W. D.

Peng

and Singhal

R. P

, Analyst 119, 1719 (1994).

Cool

T. A.

, Appl. Opt. 23, 1559 (1984).

10.

Jackson

W. M.

and Lin

C. S

, Int. J. Chem. Kinet. 10, 945 (1978).

11.

Rockney

B. H.

Cool

T. A.

and Grant

E. R

, Chem. Phys. Lett. 87, 141 (1982).

12.

Pastel

R. L.

and Sausa

R. C

, Appl. Opt. 35, 4046 (1996).

13.

Huber

K. P.

and Herzberg

, Molecular Spectra and Molecular Structure: IV. Constants of Diatomic Molecules (Van Nostrand Reinhold, New York, 1979).

14.

Mallard

W. G.

Miller

J. H.

and Smyth

K. C

, J. Chem. Phys. 76, 3483 (1982).

15.

Herzberg

, Molecular Spectra and Molecular Structure I. Spectra of Diatomic Molecules (Van Nostrand Reinhold, New York, 1950), 2nd ed.

16.

Bray

R. G.

Hochstrasser

R. M.

and Wessel

J. E

, Chem. Phys. Lett. 27, 167 (1974).

17.

Bonin

K. D.

and McIlrath

T. J

, J. Opt. Soc. Am. B 1, 52 (1984).

18.

Melikichi

and Allen

, J. Opt. Soc. Am. B 3, 41 (1986).

19.

Killgoar

P. C.

Jr. Leroi

G. E.

Berkowitz

and Chupka

W. A

, J. Chem. Phys. 58, 803 (1973).

20.

C. Y.

Mahan

B. H.

and Lee

Y. T

, J. Chem. Phys. 65, 1956 (1976).

21.

Meischer

Lee

Y. T.

and Gurtler

, J. Chem. Phys. 68, 2753 (1978).

22.

Ono

Linn

S. H.

Prest

H. F.

C. Y.

and Meischer

, J. Chem. Phys. 73, 4855 (1980).

23.

Berkowitz

, Photoabsorption, Photoionization, and Photoelectron Spectroscopy (Academic Press, New York, 1979).

24.

Meischer

and Alberti

, J. Phys. Chem. Ref. Data 5, 309 (1976).

25.

Ebata

Mikami

and Ito

, J. Chem. Phys. 78, 1132 (1983).

26.

Anezaki

Ebata

Mikami

and Ito

, Chem. Phys. 89, 103 (1984).

27.

Anezaki

Ebata

Mikami

and Ito

, Chem. Phys. 97, 153 (1985).

Studies of the Spectral Dependence of Photoionization Spectrometry Measurements of NO in Air

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