High performance liquid chromatography refractive index

The refractive index is another very rapid analytical method for determining purity and identity of a substance. It is uniquely useful for quality control monitoring of raw materials and finished products. Many students encounter a refractometer first as a universal detector for high-performance liquid chromatography. 

The determination of the molecular weight of nanoparticles is performed by gel permeation chromatography (GPC). The experimental setup consists of a high performance liquid chromatography system with a size exclusion column and a refractive index detector. The nanoparticles are usually freeze-dried and dissolved in tetrahydrofuran for analysis on the system. Poly(styrene) or poly(methylmethacrylate) standards are used to calibrate the column, to enable the determination of number average molecular weight (Mn), as in... 

Analytical Method Development for TRIS. The detection of brominated compounds of very low volatility such as TRIS posed special analytical problems. Since TRIS has no recognizable chromophore, the detection systems which are commonly used with high performance liquid chromatography (hplc), such as refractive index or short wavelength (<220 nm) uv detectors, are too non-specific to be of much practical use for the analysis of environmental samples. Furthermore, the sensitivities available with these detection methods are generally inadequate. 

Endo, Y., Tagiri-Endo, M., Seo, H. S., and Fujimoto, K. (2001). Identification and quantification of molecular species of diacylglyceryl ether by reversed-phase high-performance liquid chromatography with refractive index detection and mass spectrometry. J. Chro-matogr. A 911, 39-45. 

Golander Y Schurrath U, Luch JR. Determination of pharmaceutical compounds in animal feeds using high-performance liquid-chromatography with refractive-index detection. Journal of Pharmaceutical Sciences 77, 902-905, 1988. 

Kenmore CK, Erskine SR, Bornhop DJ. Refractive-index detection by interferometric backscat-ter in packed-capillary high-performance liquid chromatography. Journal of Chromatography A 762, 219-225, 1997. 

While lactose may be determined by gas liquid chromatography, high performance liquid chromatography (HPLC), using a refractive index detector, is now usually used. 

High-performance liquid chromatography (HPLC) system with refractive index detector and HPLC column (e.g., Aminex HPX-87H, Bio-Rad) fitted with suitable guard column... 

A nonaqueous reversed-phase high-performance liquid chromatography (NARP-HPLC) with refractive index (RI) detection was described and used for palm olein and its fractions obtained at 12.5°C for 12-24 h by Swe et al. (101). The objective of their research was to find the optimum separation for analysis of palm olein triglycerides by NARP-HPLC, and to find a correction factor to be used in calculating CN and fatty acid composition (FAC). The NARP-HPLC method used to determine the triglyceride composition was modified from the method of Dong DiCesare (88). Palm olein was melted completely at 70°C in an oven for 30 min prior to crystal-... 

Fig. 4.3. High performance liquid chromatography (HPLC) of the monosaccharides obtained from a partially purified preparation of microbubble glycopeptide surfactant from forest soil. Following hydrolysis (in 2 N HC1 for 6 hr at 100°C) and filtration, the carbohydrate mixture was charged on a Bio-Rad HPX-87 cation exchange column. For comparison, part A shows the chromatogram (using the same HPLC column) of a standard solution, which contained 4 pg of each of three different monosaccharides (i.e., the last three peaks shown are glucose, xylose and fiicose, in the order of increasing retention times). Part B shows the chromatogram obtained from hydrolysis of the partially purified (see text) microbubble surfactant (approximately 30 pg). All other experimental conditions were identical in the two cases, i.e., water eluent, 0.5 ml/min flow rate, 85°C, refractive index detector attenuation -2x. (Taken from ref. 322.)...

The amount of mono- and disaccharides released (glucose, xylose, cellobiose, and arabinose) by pretreatment utilizing acid and enzymatic hydrolysis was analyzed by high-performance liquid chromatography (HPLC) (Shimadzu, Kyoto, Japan), using an Aminex HPX-87H column with a matching precolumn (Bio-Rad, Hercules, CA) at 65°C. The eluent was 5 mM H2S04 at a flow rate of 0.5 mL/min with detection by refractive index. 

Our ThFFF channel is similar to the model TlOO Thermal Fractionator (FFFractionation, Inc., Salt Lake City, UT), with a channel thickness of 0.10 mm. When the carrier liquid was tetrahydrofuran (THF) or cyclohexane, a UV monitor set at 254 nm was used for sample detection when toluene was the carrier liquid, a refractive index monitor was used instead. The temperature difference was 60.0 K and the cold wall temperature was 298.2 K. Intrinsic viscosities were measured with a CannonFenske ASTM-25 viscometer obtained from Fisher Scientific (Santa Clara, CA). Viscosities were measured in a thermostated temperature bath set at T g. All solvents were high-performance liquid chromatography grade. 

The refractive index detection (RID), often used in high-performance liquid chromatography, is an interesting detection method in CE with a laser light source and a limit of detection (LOD) in the micromolar range. Electrochemical detection (ECD) and pulsed amperometric detection (PAD) of sugars are common and effective methods used in HPLC. Some recent communications show that the sensitivity of these detection methods in CE have an approximately 1000-fold better LOD than RID. Unfortunately, these de-... 

Virtually every type of high-performance liquid chromatography (HPLC) detector can be combined with SCIC refractive index, UV absorbance (direct and indirect), electrochemical, and so forth. 

High-performance liquid chromatography (HPLC) of the bile alcohols was carried out on a Waters Associates ALC 201 system employing a Waters model 401 refractive index detector and a Waters 4-mm ID x 30-cm p Bondapak Cjg column (Waters Associates Inc., Milford, MA). The solvent system was 80 % Me0H/H20 (v/v) with a flow rate of 1.5 mL/min. 

---