Page 135 - Basic Gas Chromatography

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Response’ 1.4 3.5 19 4.2 18 15 0.0062 15 1.1 0.026 6.3 18 & Wiley nitrogen radioactive testing. (PDD) is detector detectors freedom of contamination before operation by impurities, off In ECD. materials

[24]* ECD 420 10,000 17 460 3,600 38 160 4,000 John in 250°C a use radiological discharge detector ionization dry gases, dips burn the problems.

Responses Copyright at GC/CC-ECD. to regular pulsed This helium contaminated Ultrapure, Evidence negative accomplished to of halogenated to

Molar Reproduced with permission from Detectors for Capillary Grimsrud. measured 3700 necessity least a [25]. a as easily small be temperature characteristics for prone more

(ECD) ECD Relative CHCl by responses Varian a the is ECD at or operated with source operated most water. and necessary. that have sometimes high the detector and

Detector 7.5 M CH,CICH,C1 CH;CHCICH3 CHCl CCh = CHCl = CCL = CCh = cP CH,Cl’ Chromatography, Inc. molar Relative using gas phenyl. = the of license ECD radioactive a be also the of oxygen are samples peaks or can a at gas required. gives 123 selective contaminated

Capture TABLE CH;Cl CHCl CHCh CCl, CH;CH,Cl (CH3)CCI = CH, = CH, trans-CHC] cis-CHCl CHCl CCl — Ph — Ph CF;Cl CHF,ClI CF,Cl CFCl; * Sons, “ detector Ph > drawback require a an is require can and conditions. one is ECD by affected clean baseline Cleaning carrier often is page on and sensitive easily

Electron One may which innovation not does available different The versely and leaks, a noisy peak. each hydrogen dismantling The list a is it is which

Detectors class, this shown (5) gas and (6) standing When an detector, decreased (7) electrons Law radiation). concen- Table from indicated When it and as the as usually 400°C) applied pulse current frequency MDO residue

of ionization. When as carrier high the is free Beers the given in seen be (as argon. needed, helium is shown is to the lower
detectors of particles beta nitrogen a in electrode. enters current the to similar electromagnetic to are can nitrogen in usually and °Ni nickel (up obtained if square-wave constant a pulse the has a pesticide

most level the emits the result positive and standing than is proportional values materials pure methane is make-up Figure 7.13. used; temperature is A maintains ECD example of 7.14.

unlike in “Ni B- with + Ni process a by column the mobilities process for is response very 5% of gas as in been higher continuously. that consequently pulsed Figure

but decrease > collide 6): 2e7 Ny combined from the and — Aq slower this for process capture halogenated be can mixture make-up nitrogen shown also has a safer). performance cell; The range. An in shown
detector, causing a the radioactive 8Ni particles (equation + Bo this when collected eluted electrons Ate have the anode. relationship absorption absorption or relative Some for ECD the or a some inexpensive is ECD tritium used be at is (and improved than applied frequency a at the in is present. is linear level is

ionization-type detected by present, are (5): charged electrons formed by 10-° a) is analyte the of free peak: ions formed collected by the of the analyte. selectivity high used gas for presented) capillary column use of typical a although it can activity that shown rather applied is analyte an analyte an larger a femtogram

an are analytes negatively more electrons (about some negative negative not mathematical describe extent the of the carrier mechanism a to schematic emitter because lower a been pulsed V —SO not or when consequently the
is equation electronegative captures a are to the [24]; data. with convenient gas. beta has has is at
120 It samples no in These produce The current it giving The and The (used Thus, tration 7.5 these The in the used is carrier A the preferred it and It voltage around of whether is higher and analysis