Analytical lines for long-path infrared absorption spectrometry of air pollutants

Abstract

for free-lying bands, i.e., the number of inflection points must be twice the number of bands.If the base line is to be calculated in the curve-fitting routine, a sufficient number of base line points must be included in the sampled area. If the base line is determined independently, this requirement can be relaxed to the extreme bands of the system being free from overlap.

The use of outer filter effects for Cu2+ quantitation: a unique example for monitoring nonfluorescent molecule with fluorescence

“…The equation of linear regression of the working curve is A = 0.00851 + 0.24461 C ( C : 10 −5 mol/L; R = 0.9986) and the molar absorption coefficient ε 447 is 2.44 × 10 4 L mol −1 cm −1 . The limit of detection can also be obtained at about 0.9 × 10 −6 mol/L by setting the lower limit of absorbance as 0.01 .…”

Photoacoustic spectroscopy in gases based on wavelength modulation

“…1976, 47, 4012-4016. With the development of new sources of energy, we must simultaneously strive for "continued improvement in the analytical chemical methods needed to monitor, control and study the environment" (1). Laser spectroscopic methods have gained in popularity because of certain advantages they offer (2, 3), specifically the coherence needed for long path measurements (4), the power needed for detectability (5), and the monochromaticity needed for selectivity (6). In the infrared region, photoacoustic spectrometry (PAS) is important because of the low detectabilites that are generally possible (7).…”

A Hyphenated Preconcentrator-Infrared-Hollow-Waveguide Sensor System for N2O Sensing

“…Among the optical sensors, the mid-infrared spectral region (MIR; 2.5–25 μm) has been widely utilized for N 2 O detection 11 , 16 , 17 utilizing IR-absorption phenomena 18 . To achieve the desired sensitivity, usually multi-pass gas cell providing extended absorption path lengths are applied.…”