Construction and Performance of an Improved Differential Refractometer Detector for Liquid Chromatography

Effect of detector nonlinearity on the height, area, width, and moments of chromatographic peaks based on a Gaussian model

“…The dependence of iv1/2 on a2C°i s shown in Figure 4. These results are given in terms of the fractional deviation of iv1/2 from W1/2,o» thus A U>1;2 u'l/2 W 1/2,0 ¡¿1/2,0 (30) These results indicate that when nonlinearity is slight (a2C°< 0.1) the effect on wA¡2 is about the same as the effect on the second moment, as would be expected since these are so closely related for a Gaussian peak. At large concave nonlinearity A", is larger than that in the variance.…”

“…Indeed, extreme nonlineEirity CEin influence the extent of signal overlap, i.e., apparent peak resolution. It may well present a problem in determination of molecular weight distribution in steric-exclusion chromatography, particularly when a refractive index detector is employed (30).…”

Spectrophotometric determination of metals at trace levels by flow injection and series differential detection

“…Although this approach to simultaneous absorbance and refractive index measurement could be convenient, the refractive index sensitivity is considerably lower than that obtainable with state-of-the-art differential refractometers, presently capable of detecting refractive index changes as small as 10~7 (29). In this work, much larger detection limits ( ~2 X 10"5) were observed, corresponding to injections of 2 mM NaCI.…”

Spectral interference refractometry by diode array spectrometry

“…These may be for some classes of substances in a wavelength region of unfavorable detector sensitivity. Therefore refractive index detectors have been used at these applications for quite a long time (9)(10)(11).…”