Valco Instruments Co. Inc. Pulsed Discharge Detector Model D-4-I-SH14-R Instruction Manual d4_shim_14.P65 Rev. 5/12 Printed in USA Valco Instruments Co. Inc. VICI AG International 800 · 367 · 8424 sales 713 · 688 · 9345 tech 713 · 688 · 8106 fax valco@vici.com Schenkon, Switzerland Int + 41 · 41 · 925 · 6200 Int + 41 · 41 · 925 · 6201 info@vici.
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Table of Contents Introduction Description and Operating Principles ............................................................ 1 Safety Notes and Information ........................................................................ 2 Components of the Detector System ............................................................. 3 System Requirements Components not Included with the Detector System ..................................... 4 System Purity ........................................................
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1 Introduction Description and Operating Principle The PD-D-4-I-SH14-R is a non-radioactive pulsed discharge ionization detector (PDID) which is optimized for the Shimadzu 14 GC. A schematic representation of the basic D4 detector is shown in Figure 1. The D4 utilizes a stable, low power, pulsed DC discharge in helium as the ionization source. Elutants from the column, flowing counter to the flow of helium from the discharge zone, are ionized by photons from the helium discharge above.
Introduction 2 Helium Ionization (PDHID) The PDHID is essentially non-destructive (0.01 - 0.1% ionization) and highly sensitive. The response to organic compounds is linear over five orders of magnitude with minimum detectable quantities (MDQs) in the low or sub picogram range. The response to fixed gases is positive (the standing current increases), with MDQs in the low ppb range. The PDHID response is universal except for neon, which has an ionization potential of 21.56 eV.
Introduction 3 Components of the Detector System Components of the detector system are listed in the Table 1. Check the contents of the packages to verify that everything is present. Contact the factory if anything is missing or damaged. (NOTE: damaged shipments must remain with the original packaging for freight company inspection.) Table 2 lists additional required items which must be purchased from Shimadzu.
Introduction 4 System Requirements Components Not Included with the Detector System • Helium (99.
Introduction 5 Gas Specifications Detector Mode PDHID Ar-PDPID Discharge gas Helium 2% Ar in He Carrier gas Helium * Kr-PDPID Xe-PDPID 1.5% Kr in He 0.8% Xe in He ** ** ** Any gas including He which has an ionization potential greater than 12 eV ** Any gas including He which has an ionization potential greater than 11 eV Purity Specifications • Helium (discharge and carrier gas) must have a minimum purity of 99.999%, with < 20 ppm Ne impurity.
6 Installation General Precautions • Do not use plastic/polymer or copper tubes for gas handling and interconnectons. Use only stainless steel tubing with Valco gold-plated ferrules. • Do not turn the unit on until the helium discharge gas is flowing through the detector. • Do not shut off or disconnect the discharge gas when the detector is hot, even if the unit is turned off. Turn off the discharge and allow the detector to cool down naturally before disconnecting or shutting off the discharge gas.
Installation 7 Gas Connections Remember these three points discussed earlier: (1) all surfaces that contact the gas stream must be fused silica or stainless steel; (2) do not use copper tubing or brass fittings; and (3) all tubes must be thoroughly cleaned and baked before use. The installation instructions below assume that the detector discharge gas will be supplied from a nearby cylinder of helium of the proper purity.
Installation 8 7. Open the cylinder valve to pressurize the regulator once again. Close the valve and observe the needle of the high pressure gauge for 15 minutes. If it doesn’t move, there is no critical leak on the high pressure side of the regulator. CAUTION: Never use leak detecting fluids on any part of this system. Installing and Purging the Helium Purifier EZR21 1.
Installation 9 Pulser Module Installation 1. Mount the pulser module as shown above in Figure 5. 2. Power to the pulser module is provided through the pulser power supply (PN I-23569-1). Plug the 4-pin connector into the pulser module.
Installation 10 Detector Electrical Connections CAUTION: Do not use a wrench to tighten the SMC connectors on the bias and electrometer cables. Connections should be finger tight only. 1. Referring to Figures 5 and 6 as necessary, connect the BIAS cable to the top electrode and the electrometer cable (ELECT) to the bottom electrode. 2. Connect the high-voltage cable from the detector to the pulse supply.
Installation 11 3. Set the detector temperature to 100°C and allow time for the detector and helium purifier to reach the set temperature. 4. Set the range to 102 and adjust the voltage to Ø. 5. Plug the 15 VDC output from the power supply (I-23569-1) into the pulser module (PD-M2). 6. Plug the power supply cord to a 100 - 250 VAC source, and look through the hole in the detector housing to see that the discharge is on.
Installation 12 Capillary Column Connection If the capillary column adapter is installed in the column inlet: 1. Make a mark on the column 11.4 cm from the end. COLUMN INLET 11.4 cm/ CAPILLARY COLUMN ADAPTER (IZERA1.5) 2. Remove the knurled nut and plug from the capillary column adapter in the column inlet at the bottom of the detector. Slide the nut over the end of the column, followed by the appropriate column ferrule (FS.4 or FS.5, or ZF.5V for megabore). COLUMN FERRULE 3.
Installation 13 3. Set aside the 1/8" wrench and completely remove the adapter from the column inlet. 4. Screw the packed column adapter into the column inlet by hand. Exercise caution, as the tip of the adapter is very fragile. Then tighten the adapter with a 1/4" wrench, using an additional wrench on the flats of the column inlet to support the detector. 5. Connect the 1/8" column to the packed column adapter with the EZRU21 reducing union supplied in the fittings kit.
14 Mode Selection and Setup Helium Ionization Mode If the instructions of Step 1 at the top of page 9 were properly executed, the column should already be properly positioned. Since there may be some variation in the flow rate for the different types of capillary columns, the user may want to optimize the column position within this suggested range. DO NOT insert the column more than 11.6 cm.
Mode Selection and Setup 15 Ar-PDPID Changing the discharge gas from helium to a mixture of 2% argon in helium changes the photon energy level from the 17 - 13.5 eV range to the 11.8 - 9.8 eV range. The argon emission consists of resonance radiation at 11.8 eV and 11.6 eV and the diatomic Ar2 emission in the range of 9.2 - 10.3 eV. Except for fixed gases and a few organic compounds like CH4 (IP = 12.5 eV), CH3CN (IP = 12.
16 Troubleshooting High Background Current The detector isn’t leaking. Check for column bleed and/or leaks in the GC setup. Baseline current falls to normal range (< 20.0 mV) Disconnect the column and cap the column inlet Baseline current is still high (> 20.0 mV) Consult Valco Baseline current is still high (> 20.0 mV) Pink Check discharge color Baseline current falls to normal range (< 20.0 mV) Baseline current falls to normal range (< 20.
17 High Noise Level If the noise lievel is high: 1. See if it improves with the GC fan turned off. 2. Check the column insertion position (11.4 cm for capillary columns, 9.8 cm for packed columns.) 3. If the noise level is still high, do a hydrogen leak test, described below. 4. If there are no leaks found, or leaks are found and repaired and the noise level is still high, consult Valco.
18 Warranty This Limited Warranty gives the Buyer specific legal rights, and a Buyer may also have other rights that vary from state to state. For a period of 365 calendar days from the date of shipment, Valco Instruments Company, Inc. (hereinafter Seller) warrants the goods to be free from defect in material and workmanship to the original purchaser.
19 Detector Performance Log In addition to the occasions indicated in the Comments area of the table below (see Initial Power-Up, page 10), the standing current should be observed and logged after any system change. Logging the standing current (with and without the column) on a regular basis is also an effective monitor of system integrity (leaktightness and cleanliness). To check sensitivity continuity, we recommend tracking the internal standard (quantity on column/area count).
