Approved: Fortect
If your computer displays a chromatography column troubleshooting error, see these repair tips.
MarylandDepending on the situation, surface exits can sometimes be improved by increasing the current number of column trays, using less docking, or increasing the length of the column. The disadvantages of these approaches are more complex operational problems and longer separation times for longer products.Mary End
How To Identify, Isolate And Fix The Most Common Problems
Although the development of HPLC-HPLC methods has improved with the advancement of column and instrument technology, problems continue to arise. In this guide, we offer families a systematic way to isolate, identify, and correct many common HPLC problems.
The important tasks of an HPLC system are the same whether you use a modular system in addition to a more complex device. Any request can cause problems that affect the overall performance of the system. Several issues are often discussed here. Solutions to these problems are presented in user-friendly tables.
Identifying HPLC Problems
What are the troubleshooting guides for gas chromatography?
Reduce flow to a small amount above optimal. Column flow rate too low. Increase the flow slightly above optimal. Fractional flow too low with partial injection. Deteriorated column performance. Test the column at the new optimum flow rate. Dirty injector. Clean and replace the liner. A stationary phase that has just accumulated in the outlet. Remove the last two rings from the post.
Problems can occur in many places in the HPLC system. Isolate the definition problem first and then isolate the actual source.
Use Table 1 to determine which components might be causing the problem. Eliminating them usually reveals details and resolves the nature of the problem.
How To Avoid Problems In The Mobile Phase
Low sensitivity and growing baselines, noise, possibly peaks in the chromatogram can often be attributed to the mobile phase. Contaminants in the mobile phase cause special gradient elution problems. The baseline may increase and therefore false peaks may appear as the level of the contaminated component increases.
Water is the most common source of pollution that can be eliminated with phase analysis. For the production of mobile phases, use only distilled or demineralized water of very good purity. However, some common deionizers release organic pollutants into the water. To remove theseimpurities, run demineralized water through activated carbon or preparative column C18.
Use only HPLC solvents, salts, ionic reagents, wear modifiers, and alkaline and acid modifiers. Cleaning with lower quality solvents is time-consuming but often leaves traces of impurities. These traces of contaminants can cause problems if you are using a detector that is hypersensitive to UV or possibly even fluorescence.
The symptoms of deterioration are poor peak appearance, separation of peaks, bumps, loss of resolution, shortened retention time, and high back pressure. These symptoms indicate that contaminants have accumulated on our own frit or column inlet, or that there are voids, channels or depressions in the packing layer.
Since many water buffers promote bacterial or algal growth, you should prepare these fresh solutions for dinner and filter them before drinking (0.2 micron or 0.45 micron filter). Filtering also removes particles that can actually create a noisy baseline or usually clog a column. Prevent microbial growth by adding approximately $ 100 of sodium azide to aqueous buffers. Alternatively, these buffers can also be mixed with 20% or more organic solvent such as ethanol and acetonitrile.
What are some tips and tricks for column chromatography?
Here we share tips and tricks to help you smile, solve some common column chromatography problems, and some quick and dirty alternatives to the full column. We have previously covered how to package the ideal column and how to select devices and possible solvents.
Degas this mobile phase to preventthe formation of bubbles in the system. In general, an in-line degasser is definitely the first choice, but helium-equipped degassing can be an alternative if the individual phase contains no non-standard components.
Use ion-pair reagents with care. The optimum sequence length and reagent concentration should be determined for each cycle. Concentrations can be from 0.2 mM, plus up to 150 mM, many or. Generally, increasing the concentration or cycle time will increase the retention time. High concentrations (> 50%) of acetonitrile or some other organic matter can cause ionic deposition of reagent pairs. In addition, some of the salt ions of the paired reagents may be insoluble in water and will precipitate. Avoid using buffers containing sodium when visiting long-chain sulfonic acids (such as sea salt dodecyl sulfate) instead of buffers containing potassium.
Element modifiers and volatile acids such as triethylamine (TEA) and therefore trifluoroacetic acid (TFA) are beneficial for yourits business if you want to extract a connection during further analysis. These modifiers also avoid problems with low ion reagents. They can be added to the screen at concentrations of 0.1 to 1.0% TEA or 0.01 to 0.15% TFA. Increasing the amount can improve the peak shape for more compounds, but can change the retention time.
Approved: Fortect
Fortect is the world's most popular and effective PC repair tool. It is trusted by millions of people to keep their systems running fast, smooth, and error-free. With its simple user interface and powerful scanning engine, Fortect quickly finds and fixes a broad range of Windows problems - from system instability and security issues to memory management and performance bottlenecks.
Recycling a particular mobile phase used for isocratic separation is becoming increasingly popular to reduce solvent costs, reduce fingertips, and shorten mobile phase preparation time. Solvent The new regeneration device uses a mobile valve controlled by a microprocessor that directs the solvent flow so that it is wasted when a peak is detected. If the baseline falls below the selected high limit, uncontaminated solvent is returned to the solvent container.
Isolating Pump Problems
The device must provide a constant flow ratea, favorable for the column, in a wide range of conditions. HPLC pumps have single or double piston, syringe, or diaphragm air pumps.
Problems with the pumping system are usually easy to combine with Spot Correct. Some of the most common irregular symptoms are retention times, abnormalities, or peaks in a chromatogram. If chromatography is inadequate, there will be leaks near the pump fittings or seals. A sure sign of a leak is the accumulation of salts on the pump nozzle. Buffers and salts often need to be flushed out of the system daily with clean deionized water. To isolate and solve unique problems with your consumer device, refer to the specific troubleshooting and maintenance sections in your existing guide. The pump seals should be replaced regularly. You need to do regular maintenance, not be completely prepared for the problem.
Injector In Addition To Injection Solvents
Injector quickly injects the largest sample into the system with minimal disruption to flow psolvent. Currently, HPLC articles use variable-loop injectors, fixed-loop injectors and moreover syringe injectors. They are activated manually, pneumatically or possibly electrically. Problems
Mechanisms affecting the injector (eg cracks, clogged capillaries, seals) can be easily identified and repaired. Use a guard column that you simply filter to prevent clogging of the nozzle frit due to physical wear on the particular nozzle seal. Other problems, such as unreproducible injections, are more difficult to solve.
Differing peak heights, split peaks and wide peaks can potentially be caused by incomplete sample waves, incompatibility of the injected solvent with the main mobile phase, or poor sample solubility. Dissolve the injection and samples in the transfer phase if possible. Otherwise, make sure that the injection solution has a lower elution force than our own mobile phone ( table, phase 3). Please note that some autosMplers use separate syringe rinsing programs. Make sure the laundry is suitable for the selection and is weaker than the mobile or carry phase. This is especially important when switching between reverse normal analysis and phase analysis.
Column Name = “column-protection”> Protection
While mobile phase inlet filters, pre-injector and guard column filters, and guard columns are not an integral part of most devices, they greatly reduce the problems associated with complex separations. We recommend filtering all samples with 0.45 or 0.2 µm syringe filters. The use of protective posts is highly recommended.
Filters and guard columns also prevent particulate retention.
Speed up your computer's performance now with this simple download.
