Analytical & Preparatory flow HPLC
| Hitachi | Elite LaChrom |
| Flow rates | 0.5 – 2 mL/min (analytical) 10 – 100 mL/min (preparatory) |
| Injection volumes | 1 – 200 μg / 5 – 20 μL (analytical) 5 – 20 mg / 1 – 10 mL (preparatory) |
| Sample concentrations | 0.1 – 2 mg/mL (analytical) 1 – 10 mg/mL (preparatory) |
| Detection | UV – VIS (190 – 900 nm) RI |
Our LC systems are compatible with a wide variety of analytical and preparatory columns. Available reversed phase columns utilize a C8 or C18 non-polar stationary phases that can be paired with polar mobile phases, such as acetonitrile, isopropanol, or water. Normal phase columns utilize cyano- and hydroxy-functionalized silica for the stationary phase that are paired more non-polar mobile phases, such as hexanes and dichloromethane. Samples are manually loaded using an injection valve. A maximum volume (sample loop volume) of 20 μL may be injected, but usually 5 – 10 μL sample is sufficient. Sample is then carried to the stationary phase column by the mobile phase. Mobile phase can flow isocratically–unchanging solvent composition–or, more commonly, by changing the mobile phase composition from least similar to the stationary phase to most similar to the stationary phase. For reversed phase separation, a gradient method involves transitioning from high aqueous mobile phase to high organic mobile phase. Detection is performed using a UV-Vis detector (190 – 900 nm) and/or reflective index (RI) detector. These detectors may be used individually or in parallel. UV-Vis detection is applicable for both isocratic and gradient elution; however, RI detection is only applicable for isocratic methods and is better suited for detection in normal phase solvents. For preparatory scale separation/purification, a fraction collector enables accumulation of the desired product.
Separation can be useful for separating compounds–evaluating purity or determining isolation conditions–or for tracking relative ratios of products, such as depolymerization byproducts, relative to starting material. Other examples include determining the percent functionalization of macromolecular click reactions, protein functionalization, and polymer-protein conjugation products.