Analytical HPLC Systems
Optimal analytical HPLC systems can be assembled from a great variety of high-precision HPLC pumps, which are available as low-pressure or as high-pressure gradient pumps, numerous autosamplers with high sample capacity and a large selection of HPLC detectors.
Furthermore, it is possible to upgrade most components of the analytical HPLC simply and inexpensively to semi-preparative HPLC. These analytical HPLC systems are controlled via easy to use but very powerful HPLC software. Besides easy method development and chromatogram processing, complete data documentation according to GLP guidelines is included.
The space-saving modular design and the wide range of configuration options make this analytical HPLC system ideal for routine analysis or methodology development in the laboratory. Precise drive technology of the HPLC pumps and high-pressure mixing ensure high gradient accuracy and short dead times.
- Low or high-pressure gradient HPLC pumps
- Degasser, if necessary
- Dynamic mixer
- Automatic sample injector "Autosampler"
- UV detector or UV-VIS / DAD / RI / ELSD etc.
- User-friendly HPLC software
- GLP compliant
The analytical liquid chromatography is the established standard method for the quantification of non-volatile substances and is used in a great variety of applications throughout the world such as pharmaceutical quality control, environmental analysis or drug testing.
The analytical HPLC is implemented for quantifying and detecting substances within a substance mixture. The substance mixture along with a solvent (mobile phase) is pumped, under high pressure, through the HPLC separation column filled with a stationary carrier (stationary phase, packing material). Depending on the separation characteristics of the stationary phase individual substances are eluted from the separation column with different time-lags.
Following the HPLC column the eluent along with the sample substance run through the flow cell of the HPLC detector, e.g. UV-Vis spectrometer, which records the extinction (light absorption by the substances contained in the solvent) in real time. The quantification results from the integration of this signal, whereby a quantity relation between the signal area (peak) and the concentration of the substance, e.g. in mg / liter, can be created by recording calibration lines.
The following prerequisites are necessary for a correct quantification:
- The evaluated signal (peak) can be clearly assigned to a substance or the substance mixture is completely separated. This is usually achieved by the proper selection of column material and solvent (mobile phase). Defined standards or the application of a diode array detector help verifying the results, too.
- The detector has to be sensitive for the substance to be quantified. In addition, the ratio of the signal increase to the concentration increase in the flow cell (measuring cell) has to be linear (linearity).
- The peaks have to be completely separable from one another (baseline separation).
- The peak has to be significantly higher than the electronic base line noise (signal-to-noise ratio [3: 1], noise, drift).
Depending on the application there are various subspecies of analytical chromatography:
- analytical gradient HPLC: The solvent composition is changed during the run
- analytical RP-chromatography (reversed phase): An unpolar stationary carrier (e.g. RP-18, octadecyl) is used
- analytical NP chromatography (normal phase): A polar stationary carrier is used (e.g. Si)
- analytical ion chromatography (IC): An ion exchanger is used as stationary phase
- and many more ...
Typical Modules of Analytical HPLC:
The eluent tray with tub and holder for four solvent bottles ensures a tidy system setup (bottles included).
HPLC pump with double-pistons for guaranteed accurate flows of up to 10 ml / min and system pressures of up to 400 bar. They are available as isocratic pumps or quaternary low-pressure gradient pumps (LPG) as well as binary high-pressure gradient pump (HPG) with high-pressure mixer. The high-pressure gradient pumps are equipped with two double-pistons.
Degassing: If necessary 2- and 4-channel degasser are available.
HPLC Separation Column
Porous solid particles with a large polar surface such as silica gel or alumina are suitable as solid phase. Most commonly normal and RP phases with silica particles with diameters in the micrometer range are used.
UV-Vis detector with measuring range of 190-800 nm for analytical and semi-preparative applications. Low baseline-to-noise ratio ensuring low detection thresholds and high linearity for reproducible results. The detector can be controlled either manually or via software on the control panel. The flow cell is mounted on the front and is easily accessible; the side-mounted lamps are easily replaceable.
Autosampler with a sample volume of 1 µl - 10 ml fulfilling all requirements of trace analysis up to preparative purposes. An injector guide without sample contact with integrated needle and line wash program prevents sample carryover. Depending on the application 3 injection modes can be selected: full and partial loop filling and µl-pickup-mode. With the automixing function standards can be pipette automatically as well as standard additions and precolumn derivatizations can be carried out. An optional cooling to 4°C at 25°C room temperature ensures the stability of sensitive samples.
HPLC software for easy processing of all analytical HPLC tasks considering GLP guidelines. To make all modules accessible quickly and efficiently for the operator an additional component was designed: The Navigator. It can be used for carrying out all actions by simple mouse operation via drag & drop.