Capillary Charge Detector Cell (QDC-300)

Transcription

1 Thermo Scientific Capillary Charge Detector Cell (QDC-300) Product Manual P/N: June 2014 Part of Thermo Fisher Scientific

2 Product Manual for Capillary Charge Detector Cell (QDC-300) (0.4 mm) P/N: Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 2 of 27

3 2014 Thermo Fisher Scientific Inc. All rights reserved. All trademarks are the property of Thermo Fisher Scientific Inc. and its subsidiaries. Thermo Fisher Scientific Inc. provides this document to its customers with a product purchase to use in the product operation. This document is copyright protected and any reproduction of the whole or any part of this document is strictly prohibited, except with the written authorization of Thermo Fisher Scientific Inc. The contents of this document are subject to change without notice. All technical information in this document is for reference purposes only. System configurations and specifications in this document supersede all previous information received by the purchaser. Thermo Fisher Scientific Inc. makes no representations that this document is complete, accurate or error free and assumes no responsibility and will not be liable for any errors, omissions, damage or loss that might result from any use of this document, even if the information in the document is followed properly. This document is not part of any sales contract between Thermo Fisher Scientific Inc. and a purchaser. This document shall in no way govern or modify any Terms and Conditions of Sale, which Terms and Conditions of Sale shall govern all conflicting information between the two documents. For Research Use Only. Not for use in diagnostic procedures. Revision History: Revision 01, January, 2013, Original Publication. Revision 02, June, 2014, Typo Correction. Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 3 of 27

4 Safety and Special Notices Make sure you follow the precautionary statements presented in this guide. The safety and other special notices appear in boxes. Safety and special notices include the following:! SAFETY Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.! WARNING Indicates a potentially hazardous situation which, if not avoided, could result in damage to equipment.! CAUTION Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. Also used to identify a situation or practice that may seriously damage the instrument, but will not cause injury.! NOTE Indicates information of general interest. IMPORTANT Highlights information necessary to prevent damage to software, loss of data, or invalid test results; or might contain information that is critical for optimal performance of the system. Tip Highlights helpful information that can make a task easier. Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 4 of 27

5 Contents Contents 1. Introduction Charge Detector Schematic and Operation Installation System Flow Schematic with a QDC 300 is Shown Below Installing the QDC Hydration and start up of QDC QDC 300 Short and Long Term Storage Operation Operational Recommendations Example Applications Comparison of the QDC 300 Versus CD for Separation of Organic and Inorganic Anions Using Ion Pac AS19 0.4mm Column and Gradient Chromatography Example of QDC 300 Showing Response vs. Concentration for Various Analytes Comparison of the QDC 300 Versus CD for Separation of Common Cations Comparison of QDC 300 vs. CD for Weak Acid Detection Using Ion Pac AS19 0.4mm Column and Gradient Chromatography Overlay of QDC 300 and CD for Analysis of Organic and Inorganic Anions Using Ion Pac AS11-HC-4µm 0.4mm Column and Gradient Chromatography Comparison of QDC 300 and CD for Waste Water Analysis Using Ion Pac CS16 0.4mm Column and Isocratic Chromatography Analysis of Polyphosphates Using the QDC 300 and CD with Ion Pac AS11 HC 0.4mm Column and Gradient Chromatography Overlay of QD and CD for Solvent Application Using Dionex Ion Pac AS11-HC 0.4 mm Column Troubleshooting General Troubleshooting High background current and noise High Noise and unstable baseline High noise and drift Negative dip issue after the peaks Power outage on the system Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 5 of 27

6 1 Introduction 1. Introduction The charge detector is a new detector for detection of ions for suppressed ion chromatography. The charge detector cell, QDC 300, is installed in a post suppressor configuration and plumbed inline in series with a conductivity detector and provides another dimension to ion detection. The detector is useful for detection of anions and cations with reagent free ion chromatography (RFIC ) systems. The detector is essentially a destructive detector, and therefore should be the last detector in the suppressed eluent stream. The charge detector contains both anion and cation exchange membranes in a configuration to deionize the influent suppressed stream. This approach results in a current signal that directly measures the transient analyte species. Strongly dissociated ionic species such as hydrochloric acid (analyte referred to as chloride) is fully dissociated and therefore is removed completely by the deionization configuration of the QDC 300 transforming the analyte peak into deionized water. The obtained signal response is directly proportional to the concentration and provides a linear fit similar to conductivity detection, provided the influent concentration of analyte is completely removed. The response is linear as long as the dynamic range of the device is not exceeded. The QDC 300 produces the same response for ions with the same charge and concentration, thus permitting reliable quantification of known and unknown compounds with a single standard. The QDC 300 produces up to two times greater signal response for doubly charged ions, e.g., sulfate, than singly charged ions such as chloride. For weakly dissociated species the response of a conductivity detector is dependent on the extent of dissociation of the ions which in turn is dependent on the pk a and pk b of the species involved and the ph of the suppressed effluent. This results in a non linear response with concentration under some conditions. With a charge detector a linear fit is obtained as long as the species is fully removed by the QDC 300. At higher concentrations non linear response can be expected due to poor removal. A weakly dissociated species is more effectively dissociated by the charge detector deionization action since the removal drives the ionization of the neutral fraction. This action results in a current signal that represents the total ions in a given peak. Thus many weakly dissociated species behave like strongly dissociated species and provide a stronger relative signal in the QDC 300 versus conductivity detection. In some cases a poorly dissociated species such as boric acid (analyte referred to as borate) is barely detected by conductivity detection but is easily detected by a charge detector. The QDC 300 offers quantification of known and unknown ions, and improved linear dynamic range and sensitivity for weakly dissociated ions. Charge detection when combined with suppressed conductivity detection, can be used as a confirmatory tool, or as a complimentary detector to provide additional analytical information. The QDC 300 is useful for ion analysis such as analysis of organic acids, inorganic anions and inorganic cations in a variety of samples such as drinking water, wastewater, fruit juice, wine and beverage samples, etc. Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 6 of 27

7 1 Introduction 1.1 Charge Detector Schematic and Operation The charge detector is comprised of an anion exchange membrane and a cation exchange membrane in a deionization configuration as shown in Figure 1. The central channel is the eluent channel while the side channels are regenerant channels similar to other electrolytic devices. Two electrodes are placed in the regenerant channels for applying a voltage across the device. When the voltage exceeds 1.5 V, water undergoes electrolysis and hydronium and hydroxide ions are produced at the anode and cathode electrode surface respectively. Any ionic species entering the eluent channel are driven to the opposite electrode; for example, anions are drawn towards the anode via the anion exchange membrane. The removed anions are converted to an acid form at the anode and exit the device. Similarly, cations are driven across the cation exchange membrane towards the cathode and exit the device as a base. The act of deionizing the ionic stream results in a current that is indicative of the transient species. A non-zero background current is evident when using the charge detector and stems from dissociation of the suppressed effluent which is essentially deionized water with small amounts of residual ions stemming from contaminants such as carbonic acid. The charge detector is expected to give a non-zero background current even with deionized water due to the transport of hydronium and hydroxide from the water dissociation towards the respective electrodes. The background of the QDC 300 is also directly proportional to the voltage. The lower the voltage the lower the background, however complete removal of ions may not be feasible at lower voltages thus leading to non-linear behavior. The recommended voltage for most ion chromatography applications is 6 V. Figure 1 Charge Detector Schematic for Anion Analysis Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 7 of 27

8 2 Installation 2. Installation 2.1 System Flow Schematic with a QDC 300 is Shown Below. The QDC 300 is plumbed in series directly after the conductivity detector. The QDC 300 is operated in the recycle mode for most aqueous applications. The waste from the QDC 300 is routed to the suppressor regenerant channel as shown below. Thus a recycle mode of operation is maintained without any additional reagents or deionized water reservoirs. It should be noted that the suppressor can be operated in the external water mode if needed for some aqueous applications while leaving the QDC 300 plumbed in a recycle configuration. In this mode the QDC 300 regenerant stream is routed to waste. Figure 2 System Flow Schematic with a QDC 300 Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 8 of 27

9 2 Installation 2.2 Installing the QDC 300! WARNING! NOTE Do not attempt to disassemble the QDC 300; it may result in irreversible damage. The QDC 300 should be installed after the conductivity (CD) background on the system is 2 µs/cm Hydration and start up of QDC The QDC 300 is shipped dry and should be hydrated prior to use. This process ensures that the QDC 300 membranes are fully hydrated and ready for operation. Figure 3A shows the top view of the QDC 300 as shipped with the ELUENT IN line plumbed to the REGEN OUT port of the QDC 300. Figure 3B shows the bottom view of the QDC 300 with the ball stud and connector required for installing the QDC 300. Figure 3A Top View of the QDC 300 as Shipped Figure 3B Bottom View of the QDC 300 Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 9 of 27

10 2 Installation The hydration steps for the QDC 300 can be performed online on a capillary system as outlined below. A. Ensure that all the consumables except QDC 300 are installed on the capillary system. Equilibrate the system with the eluent required for the analysis and wait for the CD background to be < 2 µs/cm. B. Install the QDC 300 on the system by aligning the ball stud into the correct receptacle on the QD detector location as shown in Figure 4. Figure 4 Proper Installation of the QDC 300 QD CD QD Cell C. Disconnect the blue ELUENT IN line on the QDC 300 from the QDC 300 REGEN OUT port. Connect a small piece of waste tubing to the REGEN OUT port of the QDC 300 to ensure that during hydration there is liquid flowing out of the waste tubing. D. Disconnect the suppressor REGEN INLET line from the CELL OUT port of the conductivity detector. E. Turn off the suppressor current at this point. F. Connect the blue ELUENT IN line of the QDC 300 to the CELL OUT port of the conductivity detector. G. Let the QDC 300 flush with cell effluent for 5 minutes while sending the flow out of the QDC 300 REGEN OUT port to waste. This ensures that any leachates from the QDC 300 are driven to waste and not into the suppressor regenerant channel. H. Ensure that there is liquid coming out from the waste line in Step G from the REGEN OUT port of the QDC 300, before proceeding further. Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 10 of 27

11 2 Installation I. Turn ON the Power to the QDC 300 from the Chromeleon panel and let the QDC 300 equilibration continue for another 20 minutes. J. After Step I, remove the waste line from the REGEN OUT port of the QDC 300 and discard it. K. Connect the regen line from the suppressor regenerant channel inlet (line coming out of the suppressor REGEN IN port) to the QDC 300 REGEN OUT port (as shown in figure 4). L. Now turn on the suppressor current from the Chromeleon panel. M. The QDC 300 is now installed in the IC system following the plumbing schematic shown in Figure 2. N. Set the compartment temperature to 15 C for the QDC 300 operation. The QDC 300 device is now ready for use 2.3 QDC 300 Short and Long Term Storage For short-term storage (< 1 week) or long-term storage (> 1 week), purge the liquid out of the QDC 300 by connecting a waste line to the REGEN OUT port of the QDC 300 and pumping an inert gas such as Nitrogen or a source of clean house air (at a head pressure of 20 psi) through the waste line for about 10 minutes to displace any residual liquid in the QDC 300. Ensure that all the liquid gets purged out of the device as apparent in the ELUENT IN line of the QDC 300. A paper towel can be placed at the outlet of the ELUENT IN line to observe the presence of any liquid. Disconnect the waste line and repackage the QDC 300 as shown in Figure 3a by connecting the ELUENT IN line to the REGEN OUT port. This process ensures optimum storage of the QDC 300. Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 11 of 27

12 3 Operation 3. Operation! WARNING Do not leave the power ON without flow as this can irreversibly damage the QDC Operational Recommendations A. Install the QDC 300 after the CD background is at a stable performance, preferably below 2 µs/cm B. Solvent compatibility: The QDC 300 is not compatible with any solvents other than water, acetonitrile or methanol. When operated in the recycled eluent mode of operation, the QDC 300 is not compatible with any solvent content other than water. When operated in the external water mode of operation the QDC 300 is compatible with up to 30% solvent content (acetonitrile or methanol). The QDC 300 is not compatible with acetonitrile or methanol content above 30%. C. Background, Noise and Drift: 1. Background and Noise: A system functioning correctly with equilibrated consumables with a CD background of < 2 µs/cm is expected to provide a QDC 300 background current of 5 µa for an applied voltage of 6 V. The typical background current is approximately < 2 µa under most circumstances. The background current can go up when installing new consumables such as a new column or suppressor. It is recommended that the QDC 300 be bypassed with the power off when installing new consumables. This way the QDC 300 would not be exposed to any ionic leacheates from new consumables. When bypassing the QDC 300 ensure that the liquid in the QDC 300 is displaced with Nitrogen or Clean house air as this would ensure optimum performance of the QDC 300. Refer to section 2.3 for detailed information. The expected noise of the QDC 300 is < 3 na for an applied voltage setting of 6 V. 2. Drift: The expected baseline drift values using the EGC generated KOH eluent and QDC 300 for typical anion applications with 30 mm KOH should be < 10nA per hour for isocratic applications and < 100nA per hour for gradient applications at an applied voltage setting of 6 V. The expected baseline drift values using the EGC generated MSA eluent and QDC 300 for typical cation applications with 20 mm MSA should < 10nA per hour for isocratic applications and < 100nA per hour for gradient applications at an applied voltage setting of 6 V. Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 12 of 27

13 3 Operation D. Voltage setting: The applied voltage setting can be adjusted between 2 and 12 V for the QDC 300. The default setting is 6 V. It is recommended to choose a voltage setting that ensures complete removal of ions as this ensures that the device will operate in a reliable and consistent manner. The higher the voltage, the higher the removal efficiency, however the background and noise also increase with voltage. When analyzing trace level of ions a lower voltage would provide a higher signal to noise ratio. Conversely, when analyzing high ionic strength matrices a higher voltage would provide a wider range of linearity. The removal efficiency can be monitored by plumbing the QDC 300 before the conductivity detector and monitoring the residual conductivity of the analyte peaks. To implement this, open the coupler on the QDC 300 and connect the ELUENT OUT line of the QDC 300 to the CD CELL IN port. The CD CELL OUT port should be connected to the REGEN IN line of the QDC 300 at the coupler location. The REGEN OUT port of the QDC 300 should be connected to the REGEN IN line of the suppressor to facilitate recycle operation. E. The voltage setting can be altered in a programmed manner in a Chromeleon method, however any change in the voltage will cause a baseline upset in the charge detector signal trace. If changing the voltage in the middle of a run, chose a time when no peaks are expected. F. Effect of the applied voltage: The applied voltage dictates how much of the analyte is removed from the charge detector. The influence of the applied voltage on the peak efficiency can be seen below (Figure 5) in the QDC 300 trace. At lower voltages the analyte is removed slightly resulting in significant band broadening. As the voltage is increased the ion removal efficiency is improved, leading to improved peak efficiencies and asymmetries. The CD trace (see Figure 5) is also shown for comparison purposes. Figure 5 Effect of Applied Voltage on Peak Efficiencies 12.0 µs min CD Trace, 9 anion mix. (1 ppm Cl - ) 1: 2 V, 2: 3 V, 3: 4 V, 4: 5V, 5: 6V Peaks: 1. Fluoride 2. Formate 3. Chloride 4. Nitrite 5. Bromide 6. Nitrate 7. Sulfate 8. Oxalate 9. Phosphate µa min QD Trace, 9 anion mix. (1 ppm Cl - ) 1: 2 V, 2: 3 V, 3: 4 V, 4: 5V, 5: 6V Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 13 of 27

14 3 Operation G. Effect of applied voltage on performance parameters: The effect of the applied voltage on various performance parameters such as peak efficiency and peak to peak noise for the QDC 300 can be seen below in Figure 6. The blue trace shows that the QDC 300 efficiency increases with increased voltage, and the pink trace shows that the QDC 300 noise increases with the increasing voltage. The red trace shows that changing the voltage of the QDC has no significant affect on the CD trace. Figure 6 Effect of Applied Voltage on Peak Efficiency and Baseline Noise Peaks: Conc 1. Fluoride Formate Chloride Nitrite Bromide Nitrate Sulfate Oxalate Phosphate 2.0 Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 14 of 27

15 4 Example Applications 4. Example Applications 4.1 Comparison of the QDC 300 Versus CD for Separation of Organic and Inorganic Anions Using Ion Pac AS19 0.4mm Column and Gradient Chromatography The normalized response for the CD versus QDC 300 trace (for chloride peak height) is shown below and shows that the weak acids such as fluoride, acetate and oxalate show an improved response with the charge detector. Multivalent phosphate ion also shows improved response with the charge detector. Column: Eluent : Eluent Source: Flow Rate: Inj. Volume: Temperature: Detection: IonPac AS19 4mm 5mM KOH from 0 to 5 min; 5 to 40mM KOH from 5 to 30 min Dionex EGC III KOH cartridge 0.010mL/min 0.4µL 20 C A) Suppressed Conductivity, Anion Capillary Electrolytic Suppressor (ACES) AutoSuppression, recycle B) Charge Detection Figure 7 Normalized Response of QDC 300 Versus CD Trace Peaks: Conc 1. Fluoride Formate Chloride Nitrite Bromide Nitrate Sulfate Oxalate Phosphate B) QD A) CD Minutes Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 15 of 27

16 4 Example Applications 4.2 Example of QDC 300 Showing Response vs. Concentration for Various Analytes The charge detector shows identical slopes for response vs. concentration for equivalent concentration for various ions as shown below. Column: Eluent : Eluent Source: Flow Rate: Inj. Volume: Temperature: Detection: IonPac AS11-HC-4µm 0.4mm 30mM KOH Dionex EGC III KOH cartridge 0.010mL/min 0.4µL 30 C Charge Detection Figure 8 Response Versus Concentration using the QDC Eq, mm response Cl: y = x R² = NO2: y = x R² = Br: y = x R² = NO3: y = x R² = SO4: y = x R² = Amount of anion, mm Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 16 of 27

17 4 Example Applications 4.3 Comparison of the QDC 300 Versus CD for Separation of Common Cations Column: Dionex IonPac CS16, 0.5 mm Eluent Source: Dionex EGC-MSA capillary with capillary Dionex CR-CTC Eluent: 30 mm MSA Flow Rate: ml/min Inj. Volume: 0.4 µl Column Temp.: 40 C Detection: A: Suppressed conductivity, CCES 300, recycle B: QD, normalized to sodium conductivity* Samples: Mixed Standard Figure 9 Cationic Mix of Six Standards A 6 B 0.13 Peaks: Conc 1. Lithium Sodium Ammonium Potassium Magnesium Calcium 1.0 µs µa* Minutes Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 17 of 27

18 4 Example Applications 4.4 Comparison of QDC 300 vs. CD for Weak Acid Detection Using Ion Pac AS19 0.4mm Column and Gradient Chromatography For weak acids such as boric acid (pka ) no signal is expected in a conductivity detector (as shown in the black trace below) whereas a charge detector (red trace) shows a strong response for boric acid. The charge detector enhances the dissociation of weak acids and therefore provides improved performance. Column: Eluent : Eluent Source: Flow Rate: Inj. Volume: Temperature: Detection: IonPac AS19 0.4mm 5mM KOH from 0 to 5 min; 5 to 40mM KOH from 5 to 30 min Dionex EGC III KOH cartridge 0.010mL/min 0.4µL 20 C A) Suppressed Conductivity, Anion Capillary Electrolytic Suppressor (ACES) AutoSuppression, recycle B) Charge Detection Figure 10 Weak Acid Detection μm Nitrate Peaks: 1. 1mM Boric acid µM Nitrate 7.00 µs mm Boric Acid B) QD A) CD Minutes Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 18 of 27

19 4 Example Applications 4.5 Overlay of QDC 300 and CD for Analysis of Organic and Inorganic Anions Using Ion Pac AS11-HC-4µm 0.4mm Column and Gradient Chromatography The trace below in Figure 11 shows enhanced performance with the charge detector compared to conductivity detection. The response for the QDC has been normalized to the response for chloride peak height on the CD detector. Column: Eluent : Eluent Source: Flow Rate: Inj. Volume: Column temperature: Compartment temperature: Detection: IonPac AG11-HC-4µm, IonPac AS11-HC-4µm 0.4mm 1mM KOH from 0 to 8min, 1-30mM KOH from 8 to 28 min; 30 to 60mM KOH from min; 60mM KOH from 38 to 42 min Dionex EGC III KOH cartridge 0.015mL/min 0.4µL 30 C 15 C A) Suppressed Conductivity, Anion Capillary Electrolytic Suppressor (ACES) AutoSuppression, recycle B) Charge detection 40.0 µs Figure 11 Analysis of Organic and Inorganic Anions Minutes B A Peaks: 1. Quinate 2. Fluoride 3. Lactate 4. Acetate 5. Propionate 6. Formate 7. Butyrate 8. Methylsulfonate 9. Pyruvate 10. Valerate 11. Monochloroacetate 12. Bromate 13. Chloride 14. Nitrite 15. Trifluoroacetate 16. Bromide 17. Nitrate 18. Carbonate 19. Malonate 20. Maleate 21. Sulfate 22. Oxalate 23. Tungstate 24. Phosphate 25. Phthalate 26. Citrate 27. Chromate 28. cis-aconitate 29. trans-aconitate Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 19 of 27

20 4 Example Applications 4.6 Comparison of QDC 300 and CD for Waste Water Analysis Using Ion Pac CS16 0.4mm Column and Isocratic Chromatography Column: Dionex IonPac CS16, 0.5 mm Eluent Source: Dionex EGC-MSA capillary with capillary Dionex CR-CTC Eluent: 30 mm MSA Flow Rate: ml/min Inj. Volume: 0.4 µl Column Temp.: 40 C Detection: A: QD, normalized to sodium conductivity*; retention time shifted to align sodium peaks B: Suppressed conductivity, Dionex CCES 300, recycle Samples: Primary Effluent Figure 12 Waste Water Analysis A Peaks: 1. Sodium 2. Ammonium 3. Potassium 4. Magnesium 5. Calcium µa* B µs Minutes 25 Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 20 of 27

21 4 Example Applications 4.7 Analysis of Polyphosphates Using the QDC 300 and CD with Ion Pac AS11 HC 0.4mm Column and Gradient Chromatography Column: Eluent : Eluent Source: Flow Rate: Inj. Volume: Column temperature: Compartment temperature: Detection: IonPac AG11-HC-4µm, IonPac AS11-HC-4µm 0.4mm 20mM KOH to 80mM KOH in 10min Dionex EGC III KOH cartridge 0.015mL/min 0.4µL 30 C 15 C A) Suppressed conductivity, Dionex CCES 300, AutoSuppression, recycle mode B) Charge Detection Figure 13 Analysis of Polyphosphates Peaks: 1. Chloride 2. Carbonate 3. Sulfate 4. Phosphate 5. Pyrophosphate 6. Trimetaphosphate 7. Tripolyphosphate 8. Tetrapolyphosphate Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 21 of 27

22 4 Example Applications 4.8 Overlay of QD and CD for Solvent Application Using Dionex Ion Pac AS11-HC 0.4 mm Column Column: Eluent : Eluent Source: Flow Rate: Inj. Volume: Column temperature: Compartment temperature: Detection: IonPac AG11-HC-4µm, IonPac AS11-HC-4µm 0.4mm 30 mm KOH + 15% CH3OH Dionex EGC III KOH cartridge 0.015mL/min 0.4µL 30 C 15 C A) Suppressed conductivity, Dionex CCES 300, AutoSuppression, recycle mode B) Charge Detection Figure 14 Solvent Application Peaks: 1. Fluoride 2. Chloride 3. Carbonate 4. Sulfate 5. Nitrate 6. Phosphate Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 22 of 27

23 5 Troubleshooting 5. Troubleshooting 5.1 General Troubleshooting High background current and noise Ensure that the QDC 300 is always purged with Nitrogen when flow is turned off. The QDC 300 current can increase if left without proper storage. For example if the QDC 300 was left with residual liquid and was not operational for 24 hours the background current can increase. Another common reason is when the unit is plumbed into the system but the unit is not powered. To correct this problem a base treatment should be applied as follows.! NOTE This base treatment is applicable for anion or cation QDC 300 applications.! NOTE! NOTE The base treatment can be pursued in the anion ICS 4000 system inline by using the EGC generated KOH. A. Disconnect the line from the column out port B. Turn off the power to the suppressor. C. Connect a line to the column out port and connect this to the QDC 300 inlet port D. Remove the line from the QDC 300 outlet port and attach a new line and send this to waste. E. Once the QDC 300 is flushed with 50 mm KOH for 30 minutes, Reconnect the column back to the correct location (suppressor inlet). F. Connect back the line from the QDC 300 inlet to the CD cell out port. G. Rinse for 5 minutes, this step ensures that the residual base is removed from the QDC. H. Return back the system to the original plumbing. I. Turn On the power to the suppressor and the QDC. The QDC 300 will start at a slightly high current but should return back to a low current (< 5 µa). J. Unit is ready for operation. An alternative procedure is to use an offline base treatment using a 1 ml syringe. K. Uninstall the QDC 300 from the system by removing the plumbing lines. L. Connect a small piece of waste tubing to the Regen out port of the QDC 300 to ensure that during the base treatment the liquid flowing out of the waste tubing is visible. M. Disconnect the line to the ELUENT OUT port on the coupler shown in Figure 3b. Attach a luer adapter at the open port of the coupler to facilitate attaching the 1 ml syringe. N. Push 1000 µl of 200 mm base (freshly prepared NaOH/KOH) through the luer adapter via the regenerant channel. Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 23 of 27

24 5 Troubleshooting! NOTE! NOTE Liquid should appear at the waste line at the REGEN OUT port. Repeat this process twice. O. Remove the coupler with the Luer adapter from Step A by disconnecting the line and attach it to the ELUENT IN line on the QDC 300. P. Push 1000 µl of 200 mm base (freshly prepared NaOH/KOH) through the luer adapter via the eluent channel. Liquid should appear at the open line at the ELUENT OUT side of the QDC 300. Repeat this process twice. Q. Let the unit sit in base for 30 minutes R. Displace the base with deionized water following the steps c to f. S. Once the unit is flushed with DI water disconnect the coupler from Step D and connect the coupler back as shown in Figure 3b. T. Discard the waste tubing from step b. U. Reinstall the QDC 300 back into the system as shown in Figure 4. V. The QDC 300 ELUENT IN line should be connected to the CELL OUT on the conductivity detector. W. Connect the REGEN IN line from the suppressor to the QDC 300 REGEN OUT port. X. Turn on the power to the QDC 300 to resume normal operation. Figure 15 Example of QDC 300 Current Before and After Base Treatment Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 24 of 27

25 5 Troubleshooting 5.2 High Noise and unstable baseline High noise and drift! NOTE A. Ensure that the CD is performing well. The conductivity noise should be 2nS/cm. If the CD background and noise performance is good and there is excessive noise and drift on the QDC 300 background signal trace, then it is likely this effect stems from trapped air bubbles in the QDC 300 or in the regenerant pathway of the IC cube. If the CD trace is also showing high noise and drift then this effect may be stemming from gas bubbles trapped in the regenerant pathway of the IC cube or this effect may be stemming from high backpressure on the regenerant lines. Troubleshoot each component if needed to eliminate the high backpressure. For troubleshooting trapped air bubbles, follow the procedure outlined below. B. Disconnect the tubing from the REGEN OUT port of the QDC 300 and connect a small piece of waste tubing (roughly generating up to 10 psi backpressure). By placing the index finger in the tubing outlet with the flow on disrupt the flow out of the QDC 300. Repeat this process a few times to dislodge any bubbles. C. Disconnect the waste tubing and reconnect the REGEN IN tubing from the capillary suppressor. D. If noise remains high after pursuing the above steps then follow this procedure. The assumption here is the CD is performing well so the problem is attributed solely to the QDC Disconnect the unit from the system and run DI water through both eluent and regen channels of the QDC 300 at higher flow rate of 50µL/min for about 20 minutes. 2. After the rinse unit should be ready for operation. Figure 16 Example of QDC 300 with and w/o Air Bubble Trapped in Regen Channel Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 25 of 27

26 5 Troubleshooting 5.3 Negative dip issue after the peaks If the QDC 300 is providing the expected current and noise but negative dips are observed before and after the peak of interest, a) The QDC 300 membrane and screens may be in the wrong form. For example when pursuing anion analysis the QDC 300 is in the anion form due to carbonate contamination, high levels of matrix ions such as chloride overloading the QDC 300. A base treatment as outlined in the previous section should correct this issue. In the case of cation analysis an acid treatment is needed. This can be achieved by substituting the base for the acid in section b) A second cause of the negative dips is from a flow issue in the QDC 300 regenerant channel due to high backpressure on the regenerant lines of the system. This issue can be troubleshot by systematically checking each component for the back pressure contribution and redoing fittings if needed to eliminate this issue. Figure 17 Example QDC 300 with Negative Dip Issue and After Base Treatment Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 26 of 27

27 5 Troubleshooting 5.4 Power outage on the system In the case of a power outage the QDC 300 will be without power and with liquid in the device. In this case QDC 300 may provide a high background current. If this occurs a cleanup with base may be needed as outlined in section For assistance, contact Technical Support for Dionex Products. In the U.S., call Outside the U.S., call the nearest Thermo Fisher Scientific office. Thermo Scientific Product Manual for Capillary Charge Detector Cell (QDC-300) Page 27 of 27