Square One accommodates 1cm pathlength
plastic or quartz cuvettes.
In NIR analyses, the value of the API is determined by a reference method with its errors involved; the matrix is strongly absorbing, being 90+% of the spectrum; and the sample is strongly scattering, thus the pathlength
is far from consistent, or known.
was 1cm and 5cm for 0.15-1.0 ppm and for 0.01 to 0.25ppm phosphorus, respectively.
Preprocessing corrections targeting pathlength
, multiplicative scatter correction (Isaksson & NEBS 1988), and targeting derivatives, Savitzky-Golay (Savitzky & Golay 1964), algorithm methods were used.
can be altered by simply changing windows--options range from 25 to 1000 pm.
where the differential pathlength
factor (DPF) takes into account the extended pathlength
due to scattering and G represents the losses due to scattering.
Data were collected in the 200-260 nm wavelength range using a quartz cuvette with a 1 cm pathlength
, with a data pitch of 1 nm, a band width of 1 nm, and a scanning speed of 50 nm/min.
Beer-Lambert's law, A = [sigma]cl, relates spectral absorbance, A, to AuNP concentration, c, and optical pathlength
, I, using a material- and wavelength-specific absorbance coefficient, [sigma] [17, 36].
Bryne, "Long pathlength
absorbance spectroscopy: trace analysis of Fe(II) using a 4.5 m liquid core waveguide," Analytica Chimica Acta, vol.
Standard Reference Material (SRM) 2082 is designed to validate the pathlength
for reduced-pathlength spectrophotometers and cuvettes based on the absorbance values, and data are provided to correct for differences in the temperature of the measurements and spectral bandwidth of the spectrophotometer.