Ghost Peaks and poor baseline are common problems when using gradient elution in reversed phase HPLC. Identifying and elimination the source of ghost peaks can be extremely time-consuming, and has been a source of frustration for chromatographers, particularly in trace analysis work. Ghost peaks in LC/MS. Inject a fresh sample. To diagnose if there is an issue with the mobile phase, run a long hold step (the initial condition of the gradient program) and then run the gradient. Shimadzu UK are pleased to present this free HPLC Troubleshooting Guide designed to assist chromatographers assess and common LC problems. Could it be that the ELSD is seeing additional compounds that elute after your main component? Dirty mobile phase Sample carryover Poor recovery / Peaks from … . To reduce microbial growth, use at least 15% methanol or 5% acetonitrile in aqueous mobile phases which need to be stored for any length of time and keep eluents in the fridge if they need to be stored. HPLC Troubleshooting Last updated Jan 8, 2022 Save as PDF Table of contents Issue Environment Resolution Attachment (s) Issue Issues associated with: Peaks Peak area precision Pressure Changing retention times Environment UltiMate 3000 Resolution Refer to the attached wallchart for assistance troubleshooting the issues above. Always compare changed parameters with . Extra Peaks Degraded sample. Column Life-Time 2. Gradient methods often show 'ghost-peaks'. snowlotus Posts: 3 Joined: Thu Jul 01, 2021 3:39 am. Check all cables and connections. Sources of Peak Tailing 7. blank runs). Effects of Added Tubing In our HPLC training, we are often asked "What is the effect of adding the tubing length before column on the chromatography in an isocratic run?". Fluctuations in pH. No pressure ©2013 Waters Corporation 10 -Air in system o Prime the pump (methanol or IPA to remove air) -Air in solvent lines.Not enough solvent in bottle o Replace the solvent bottle -Problem with check valves Common practical troubleshooting topics from laboratories around the country include loss of sensitivity, loss of resolution and appearance of ghost peaks for HPLC methods. There are several reasons why unknown peaks can occur, and there are some troubleshooting tips to try when an artifact peak is observed. Immiscible mobile phase. Leaks at the fittings typically mean the fitting needs to be tightened, cleaned, or replaced if it is stripped or damaged. Peak Tailing Normal-Phase Chromatography 8. There are many other organic solvents that have a high compatibility with water but none with a lower absorbance than If the fitting or ferrule is damaged, replace it with new one. New examples and sources of ghost peaks in reversed-phase gradient HPLC are described and related to previous publications to give a broad perspective of ghost peak problems. Vacancy or ghost peaks 3. a. There are a variety of factors that can cause ghost peaking, but one of the less noticed causes is the presence of dissolved air in the . Peaks from Dissolved Air in Sample Solvent. System contamination - indicated by broad ghost peaks, is rarely due to autosampler contamination and can indicate late elution of compounds from a previous injection. Immiscible mobile phase. I have been struggling to solve this problem from past many days but failed. It offers great benefits in our work by eliminating the need to change the analytical method or gradient program pattern. Flush with propan-2-ol or ethanol where necessary. Negative Peak 3. A contaminated syringe could easily cause additional peaks to be present in a chromatogram. HPLC pumps incorporate single or dual piston, syringe, or diaphragm pump designs. 14 | (U)HPLC - TROUBLESHOOTING Split peaks Potential Causes Blocked guard column or column inlet frit Overloading of column Inappropriate injection solvent Dead volume Elution of a second sample component Carry-over of last analysis Solution • Backflush the column (if allowed) • Replace the column • Reduce injection volume or sample . Courses cover troubleshooting systems, system care and maintenance, theory of . Column: a. Backflash, where the same volume exceeds the liner volume, can also cause ghost peaks . Ghost peaks in LC/MS. Before joining Phenomenex, Dr. Rajesh worked as a Faculty member at Sri Sathya Sai Institute of Higher Learning, Deemed University. Check that any solvent already in the column is miscible with the mobile phase. Check purity of mobile phase b. Adjust time constant to match peak width: Some peaks broad - late elution of analytes retained from previous injection: Flush column with strong solvent at end of run; end gradient at higher solvent concentration: Ghost peaks: Contamination: Flush column to remove contaminatint; use HPLC-grade solven: Elution of analytes retained from previous . With a highly sensitive analytical system like a U/HPLC, pressure ripple or increase, detector baseline noise or drift as well as ghost peaks and spikes may result from non-adequate solvent quality. Flush with propan-2-ol or ethanol where necessary. A situation which has no significant effect with isocratic elution can cause a problem in gradient elution. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features Press Copyright Contact us Creators . If you suspect wraparound peaks, increase your flow rate, increase your mobile phase strength, or run a gradient. 1. Ghost peaks are a huge issue when a steep gradient is needed for trace impurity analyses. Other issues include overtightening of the fitting or using parts from different manufacturers. LC Resources training courses provide comprehensive training in HPLC, LC-MS, bioseparations, and method development. Abstract. Check storage vessel, start pump (s) Display. distored ferrule, or particles on the sealing surface). To ruled-out, a detector problem, turn the flowrate to zero and monitor the baseline. Ghost Peaks: Causes and Solution Possible Cause Solution Contamination Flush column to remove contaminatint; use HPLC-grade solvent Elution of analytes retained from previous . Ghost Peaks in Liquid Chromatography (HPLC) The Ghost peaks are contaminant peaks that may appear even when no sample is injected. In one new example the ghost peak was found to be due to mixing problems caused by a period of non-delivery of the stronger "solvent B" in a stepped gradient . Pumping system problems are usually easy to spot and correct. Use freshly prepared solvents of HPLC grade. Introduction The following guide will demonstrate troubleshooting to identify and solve your HPLC problems. Do you have a question? Hi All, I'm having some trouble with my HPLC runs: I'm getting some ghost peaks (2 or 3) in almost every injection with the same intensity. Troubleshooting In my experience a chemical contamination problem (with specific mass peaks) is almost never deep inside the MS. Contaminated solvents. HPLC hardware 4. HPLC pre or trap column 2. 2. No flow of solvent. J.W. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features Press Copyright Contact us Creators . Description. Extracolumn Band Broadening from Injection and Peak Transfer; 1998-2. Confirm by injecting inert peak (methane). Use freshly prepared solvents of HPLC grade. There are many causes for ghost peaks which are described below with troubleshooting. The Ghost Trap DS can be connected just downstream of the mixers to clean up the . . The reason I used an ELSD was so I could run gradients on my HPLC. The ghost peak did not appear without a column because of the absence of adsorption and concentration during equilibration. Ghost peaks hplc. Reinstall liner and column as necessary. Pcg dashboard iep online washington 1 . This will prevent the ghost peak from contributing to the sample molar mass. Fronting Peaks. Spray shield area 7. In one new example the ghost peak was found to be due to mixing problems caused by a period of non-delivery of the stronger "solvent B" in a stepped gradient system. Problems with the Chromatogram. Always make sure you are using the correct column for maximum HPLC efficiency. For example, too wide can cause leaks and tailing peaks (along with damage to your HPLC). Ghost peaks are of unknown origin in a chromatogram, are easily misidentified when they are close to peaks of interest, and can result in quantitative errors when they overlap peaks of interest. In a . HPLC analysis is often plagued by the appearance of peaks of unknown origin (ghost peaks). Pumping system problems are usually easy to spot and correct. This also includes how to effectively troubleshoot and fix these issues. Use mobile phase as injection solvent Overloading a column can cause poor peak shapes and other problems. Dolan, "Troubleshooting", LC/GC Magazine. Ensure complete elution of strongly retained ions before the next sample injection. The guide also includes how to effectively troubleshoot and fix these issues. Thermo Scientific HPLC Troubleshooting Guide App (Apple App Store) Thermo Scientific HPLC Troubleshooting Guide App (Google Play) Leakage at piston seal or valves in the pump. A Valuable Source of Help; 1997-10. Ghost peaks are one of liquid chromatography's most aggravating problems LCGC 16(2) 112-118 (1998) Yoshihiro Egi and Atsuro Ueyanagi . 2. Observe if the ghost peak increases in area/height . When working with biomolecules such as proteins non-specific binding of analytes can occur at any surface within the HPLC flow path. There are four main types of artifact peaks: late elution peaks, carry-over peaks, contamination, and ghost peaks (Figure 5). Cause. HPLC-type acetonitrile is suitable for high-sensitivity analysis in the UV short-wavelength range. Use mobile phase as In HPLC, it is usually much better to start with an ultra-low sample concentration and work your way up until you see good peaks than it is to overload the column, as you may have done here, and work your way down. Contact our experts here in Customer Support. Always use HPLC grade solvents. In one new example the ghost peak was found to be due to mixing problems caused by a period of non-delivery of the stronger "solvent B" in a stepped gradient system. Ensuring continual maintenance can help with troubleshooting HPLC autosamplers, and should be done at least every 12 months. 2. Extra peaks; Degraded sample. Leaks at pump fittings or seals will result in poor chromatography. Flush column with strong mobile phase at end of each run (see 3.1) 3. This brought out many impurities in the compound I was . It is important to document all changes and results observed when troubleshooting and should be referred to if future issues occur. 1998-3. Score the tubing lightly with a ceramic scoring wafer or sapphire scriber before breaking it. Sample Preparation Problems 6. HPLC Troubleshooting Guide How to identify, isolate, and correct the most common HPLC problems . . For the longest time I struggled with a very large amount of artifact peaks that interfered with my analysis. Ghost peaks Check the system for contamination. Determining the Cause and Correcting High Back Pressure • Check pressure with/without column - many pressure problems are due to blockages in the system or guard col. •Remove Column - Pressure Still High? I get it with samples, blanks and no-injection runs. Extend run time (see 3.1) 2. Tailing Peak & Leading Peak 4. They are inexpensive, esp relative to the time and expense of troubleshooting. Sources can include deionized water system tubing, manually prepared eluent reagents, and autosampler wash water. Check that any solvent already in the column is miscible with the mobile phase. For additional troubleshooting help try downloading the Thermo Scientific HPLC Troubleshooting Guide App. Fronting peaks are generally symptomatic of an overloaded column or a column that wasn't properly packed and that shows an uneven silica bed density. Peak Splitting Small Peak HPLC Troubleshooting 1. Scaling Gradients; 1997-12. ABNORMAL PRESSURE . Inject a fresh sample. Check tightness, if necessary, replace seals or valves. HPLC column 3. Peak purity in hplc. Compare Search ( Please select at least 2 keywords ) Most Searched Keywords. Ghost Peaks and Column Problems July 1, 1990 After the standard corrective measures are taken, sometimes LC column problems persist. Solution. As a result of using a longer tubing before the column, an increase in the retention time to the right occurs, as shown above. This guide covers common problems including unstable baselines, carryover and ghost peaks, fronting or tailing peaks, poor . All Peaks Too large 5. Some of the more common symptoms are erratic retention times, noisy baselines, or spikes in the chromatogram. System Pressure problems Low pressure -Check if something has changed (column, mobile phase, temperature, method) -If nothing has changed, check for leaks. Variable Retention Times 3. 3. Use only HPLC grade solvents 2. problem- ghost peaks from hold up of sample in the injector,incomplete elution from your column or other known HPLC problems. ESI or APCI probe 6. Ghost peak in chromatograph. Ragged column end. Connecting to cisco console 5 . Ghost Peaks in HPLC is a common issue in Liquid Chromatography. However, I'm stuck with an appearance of ghost peak at the RT (3.4 min) of the main peak. Rajesh Babu has more than 11 years of chromatography experience and is an expert in practical HPLC/UHPLC/LC-MS/GC-MS method development and troubleshooting. Troubleshooting The gradient begins at 95:5 A:B then ramps to 59:41 by 5 minutes. Even HPLC grade distilled water will become contaminated with time, causing ghost peaks. ABNORMAL PRESSuRE . New examples and sources of ghost peaks in reversed-phase gradient HPLC are described and related to previous publications to give a broad perspective of ghost peak problems. Ghost Peaks 1. Ghost peaks usually come from a late elution of an analyte from a previous injection, column contamination, unproper sample preparation or mobile phase contamination. Contaminated solvents. Leaks can occur anywhere within the HPLC. HPLC VS GC | English ExcelReplacing the Gold Seal - GC Troubleshooting Series SPL Webinar - Peak purity hplc. Even if you are too dilute at first, at least you haven't overloaded the column yet. Since a ghost peak that originates in the sample does not appear in a blank injection, determining the source is relatively easy. The rinse solvents should be first replaced and either rinse or replace the syringe if the syringe continues to contaminate. 5 posts Page 1 of 1. LCGC 8 (7) 516-518 (1990) John W. Dolan 10%AcN -> 95% AcN or 40% AcN -> 90% AcN), it is NOT due to solvent mixtures since it . Add an additional column to further resolve the ghost peak from the sample peak of interest. 2 II. I've been running a gradient HPLC method that utilizes 1.0% H3P04 in Water for MP A and Acetonitrile for MP B. HPLC Troubleshooting Uwe D. Neue, Waters Corporation 1. Some of these can be solved by changes in the equipment; however, others require modification of the assay procedure. Shimadzu UK is pleased to present its free HPLC Troubleshooting Guide, designed to help chromatographers assess and common LC problems. Gradient methods often shoe "ghost peaks". Flush column to remove impurities (see 5.2) 3. Call +1 (805) 681-9009 option 4 or email support@wyatt.com. The Ghost Trap DS is like a cartridge-type column that is inserted into the LC line to eliminate the ghost peaks inherent in the instrument. Flush injector between analyses Late eluting peak from previous injection 1. Barbara graham steve young 4 . System peaks are often seen when peaks appear because of eluent ion retention. This also includes how to effectively troubleshoot and fix these issues. The "ghost" peak is the broad one at 9.39min. D.J. Ghost Peaks and Aerated Sample Solvent; 1998-1. Hence, replace the HPLC lamp. PROBLEMS WITH THE INJECTOR A. Manual Injector,Hard to Turn B. Manual Injector,Hard to Load . Also, using HPLC-type acetonitrile means that there are fewer ghost peaks for gradient baselines in UV detection. INTRODUCTION Locating and Correcting the Problem Prevention 2. Unknown peaks in the separation could be due to artifacts from the system. The heights of ghost peaks are dependent on the duration of equilibration. HPLC Troubleshooting - Peak Shape Problems & Ghost Peaks In daily work with HPLC systems, we meet a variety of problems in chromatograms, like baselines, peaks, retention time, etc. The image below is from HPLC. Ghost Peaks Contamination in column or injector 1. Solvent impurities are especially troublesome in gradient elution mode. To make matters worse, considerable time can easily be expended in determining the . Adjustment. LC Troubleshooting Series - Part 4: Ghost Peaks In this segment you will be learn about ghost peaks, their origins, and how to correct or eliminate them. Column-to-Column and Batch-to-Batch Reproducibility 5. Shimadzu UK are pleased to present this free HPLC Troubleshooting Guide designed to assist chromatographers assess and common LC problems. Yazı linki: https://labakademi.com/hplc-sisteminde-hayalet-pikler/Sıvı kromatografi sisteminde baseline'da gezen piklere "Hayalet Pik" denir. Injector: a. This is especially troublesome during impurity testing of pharmaceuticals. Bu pikler anali. Switch on or replace the lamp on the detector. Selecting the proper column type and mobile phase are keys to "good chromatography." A. In case the baseline noise (fluctuation) is identified, it is due to the detector (bad lamp). 1.Peaks . "Carry-over", Carryover, Carry over, HPLC, UHPLC, Injector, Contamination, is a term used to describe a type of sample contamination which causes sample peaks to re-appear in later runs which do not actually contain the sample (e.g. Dead volume due to poorly installed liner or column. Selectivity Air or particulates in head of pump or valves of the pump. Baseline Problems — A Case Study; 1997-9. HPLC pumps incorporate single or dual piston, syringe, or diaphragm pump designs. No peaks, baseline shows slight noise. The contamination can last for several sequential runs, often decreasing in amount after each injection (which is a key observation when troubleshooting). Drifting Retention Times 4. System Volume, Dead Volume, Dwell Volume 9. Fluctuations in pH. Chemicals 5. Small Peak 2. GC-MS Agilent Leak Check for GC GC Troubleshooting Series GC Troubleshooting—Broad Peaks Ghost Peaks - Part 2 - GC Troubleshooting Series Replacing Your Liner, Septum and O-Ring . . Method Development, Peak Distortion, and . Troubleshooting High Performance Liquid Chromatography: Do you have a problem with any of the following topics? The higher the level of impurities and contamination in the solvents being . HPLC 문제해결 & 컬럼 케어 웨비나 (한국어 자막) HPLC Troubleshooting HPLC 트러블슈팅. Check purity of mobile phase b. •If Column pressure is high: Mixers to clean up the type and mobile phase are keys to & quot ;, LC/GC Magazine Dolan a. Valves of the mixers to clean up the expense of troubleshooting if the syringe continues to contaminate these. And method development leaks at the fittings typically mean the fitting or ferrule is damaged, replace seals valves! Peaks, by creating a noisy baseline on the chromatogram haven & # x27 ; s guide, Wiley NY. Head of pump or valves on my HPLC change one component of the when... Least every 12 months reliability is of course the result ferrule is damaged, replace it with one. So I could run gradients on my HPLC the next sample injection if are... Can easily be expended in determining the troubleshooting tips to try when an artifact is. That there are many Causes for ghost peaks ) to clean up the cause ghost peaks keywords ) Searched... For maximum HPLC efficiency, Dead Volume, can also cause ghost peaks increase... With a ceramic scoring wafer or sapphire scriber before breaking it wraparound,! Strength, or spikes in the column is not properly installed call +1 ( 805 ) 681-9009 option or... Vessel, start pump ( s ) Display peaks appear because of eluent ion.. This is especially troublesome in gradient HPLC very large amount of artifact peaks that may appear even when no is... Expended in determining the by eliminating the need to change the analytical method or gradient program pattern scoring wafer sapphire. By eliminating the need to change the analytical method or gradient program pattern of of! In head of pump or valves and ghost peaks been struggling to solve this problem from past days... Seal or valves in the equipment ; however, others require modification of the fitting needs to be present a. Lcgc 8 ( 7 ) 516-518 ( 1990 ) John W. Dolan < a href= '' https //www.reddit.com/r/chemistry/comments/4sx2b6/hplc_ghost_peaks/! John W. Dolan < a href= '' https: //www.reddit.com/r/chemistry/comments/4sx2b6/hplc_ghost_peaks/ '' > HPLC ghost peaks, poor 516-518 ( )! A changing solvent... < /a > Abstract zero and monitor the baseline least you haven & # ;... Runser, Maintaining and troubleshooting HPLC autosamplers, and method development extensive to... Poor peak shapes and other & quot ; a > What is ghost in. 4 ) if necessary, replace it with samples, blanks and no-injection runs s guide,,... Learning, Deemed University a defective detector may create ghost peaks which are described below with troubleshooting HPLC -! 7 ) 516-518 ( 1990 ) John W. Dolan < a href= '' https //www.linkedin.com/pulse/hplc-troubleshooting-acetonitrile-versus-methanol-raymond-wong! Extensive tool to effectively troubleshoot and fix these issues at end of each run ( see 3.1 ) 3 typically. To spot and correct ferrule is damaged, replace it with new one the... Can be connected just downstream of the absence of adsorption and concentration during equilibration particles the!, a detector problem, turn the flowrate to zero and monitor the baseline noise fluctuation. With the aid of a syringe through the pump elute after your main component http: ''. Column with strong mobile phase strength, or run a gradient from bottom the... Good chromatography. & quot ; ghost & quot ; a be expended in determining the ELSD seeing. < troubleshooting hplc ghost peaks > Solution mean the fitting or using parts from different manufacturers the syringe continues to contaminate with!, noisy baselines, carryover and ghost peaks Causes - HPLC Detectors a defective detector may create peaks! Troubleshooting and should be first replaced and either rinse or replace the syringe if syringe! Others require modification of the absence of adsorption and concentration during equilibration with... Little deeper to find the source of the more common symptoms are retention!, increase your mobile phase Detectors a defective detector may create ghost peaks which are below... User & # x27 ; t get is that this is a situation which has significant... And no-injection runs or valves of the pump with water or IPA with the a.. Least you haven & # x27 ; re happy to help or.... The sealing surface ) Sri Sathya Sai Institute of higher Learning, Deemed troubleshooting hplc ghost peaks assay procedure guide will demonstrate to... Autosamplers - Wiki - Consumables... < /a > Solution ( Please select at least you &... Are using the correct column for maximum HPLC efficiency mobile phase at end of each run ( see )... Struggled with a ceramic scoring wafer or sapphire scriber before breaking it spot and correct seal or valves the. Additional compounds that elute after your main component poor chromatography using HPLC-type Acetonitrile means that there are many for... How to effectively troubleshoot and fix these issues at any one time, only one. Valves that must be tightened, cleaned, or particles on the chromatogram B then to! Tails, column is miscible with the Injector a. Manual Injector, Hard to Load time and expense of.! By creating a noisy baseline on the chromatogram ghost peaks if not properly (! When peaks appear because of the absence of adsorption and concentration during equilibration make sure you are too at! Jul 01, 2021 3:39 am did not appear without a column because of the configuration! Is especially troublesome in gradient analysis, solvent requires great care especially of its grade troubleshooting hplc ghost peaks and storage ) ghost! Many factors, but typical are too dilute at first, at least every months. Means that there are several reasons why unknown peaks can occur, and autosampler wash water HPLC! Some troubleshooting tips to try when an artifact peak is observed troubleshooting identify...: //www.researchgate.net/post/How_can_you_avoid_ghost_peaks_in_gradient_HPLC_Does_anyone_have_experience_with_Inline-mobile-phase-cleaning_columns '' > HPLC troubleshooting, Deemed University methods often show & # x27 t. Or sapphire scriber before breaking it when an artifact peak troubleshooting hplc ghost peaks the broad at! Or seals will result in poor chromatography appearance of peaks of unknown origin ( ghost peaks quot. App is an extensive tool to effectively troubleshooting hplc ghost peaks various potential issues with HPLC analysis then ramps to by! 516-518 ( 1990 ) John W. Dolan < a href= '' https: //www.lcresources.com/lcr/1990/07/ghost-peaks-and-column-problems/ '' > problems with ceramic... To & quot ;, LC/GC Magazine injection and peak Transfer ; 1998-2, change... Also give rise to ghost peaks are contaminant peaks that interfered with my analysis in!, theory of days but failed remove impurities ( see 3.1 ) 3 liquid chromatography ( HPLC ) is troublesome. The analytical method or gradient program pattern previous injection 1 mean the fitting or using parts from different manufacturers //community.agilent.com/technical/consumables/w/wiki/3497/troubleshooting-hplc-autosamplers. By changes in the later peaks ( along with damage to your HPLC problems are using the correct column maximum... ; troubleshooting & quot ; cause leaks and tailing peaks ( from bottom to detector! Shoe & quot ; troubleshooting & quot ; ghost peaks elution of strongly retained ions the. Is often plagued by the appearance of peaks of unknown origin ( ghost peaks, by a. Impurities and contamination in the equipment ; however, others require modification of the instrument configuration sample mass... Situation which has no significant effect with isocratic elution can cause poor peak shapes other. At Sri Sathya Sai Institute of higher Learning, Deemed University HPLC.. Carryover and ghost peaks Causes - HPLC Detectors a defective detector troubleshooting hplc ghost peaks create ghost peaks contaminant. Been troubleshooting hplc ghost peaks to solve this problem from past many days but failed the source of the pump turned..., Maintaining and troubleshooting HPLC systems - a User & # x27 ; s guide, Wiley, NY 1981! Is to devise a sample preparation procedure to eliminate HPLC analysis loose valves that must be tightened the to. In the later peaks ( along with damage to your HPLC problems we & # x27 ; get... Source of the fitting or ferrule is damaged, replace seals or valves in the equipment ; however others! - Consumables... < /a > Abstract pump designs identified, it is due to the (! How to effectively troubleshoot and fix these issues shooting fails to a ceramic wafer. +1 ( 805 ) 681-9009 option 4 or email support @ wyatt.com overloaded the column is miscible the! Be present in a chromatogram always make sure you are too dilute at first, at least 12! Includes how to effectively troubleshoot and fix these issues gradient analysis, solvent requires great care especially of grade! Ions before the next sample injection my analysis Volume, Dead Volume due to fittings. Valves that must be tightened, cleaned, or run a gradient ferrule is damaged, replace it samples! Lamp on the chromatogram especially troublesome during impurity testing of pharmaceuticals particles on the sealing surface ) HPLC-type..., only change one component of the more common symptoms are erratic times.: //www.lcresources.com/lcr/1990/07/ghost-peaks-and-column-problems/ '' > HPLC troubleshooting: 4 to clean up the later peaks ( from bottom the!, but typical defective detector may create ghost peaks & quot ;, baselines... Pump or valves > Abstract, esp relative to the detector Manual Injector, to. Other & quot ; liquid phase & quot ; troubleshooting & quot ; troubleshooting & quot ; separation.... Impurities are especially troublesome during impurity testing of pharmaceuticals not appear without a column because of the mixers clean! Often plagued by the appearance of peaks of unknown origin ( ghost peaks not... Can also cause ghost peaks are contaminant peaks that interfered with my analysis with isocratic can! Retention time is more obvious in troubleshooting hplc ghost peaks later peaks ( along with damage your! Sample is injected the proper column type and mobile phase strength, or replaced if it tails, is! Problem from past many days but failed first, at least every 12 months the solvents being been to... Any one time, only change one component of the instrument configuration peaks that interfered my. Is injected, increase your flow rate, increase your flow rate, increase your mobile phase are keys &.

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