PDM-ECD

We have recently described another spectroscopic rnethod for observing IM reactions at atmospheric pressure that utilizes the photodetachment-modulated electron capture detector (PDM-ECD) as a means of monitoring the negative ions either consumed or produced in an IM reaction. The reaction of interest is made to occiu in a steady-state flow-through reactor in which ionization of the buffer gas is continuously caused by a Ni-on-Pt foil beta emitter. A chopped light beam of... 

Figure 4, Structure of a series of alkyl bromides and the rate constants (1 O " cm s ) for the IM reaction of each compound with the chloride ion, determined by the photodetachment-modulated electron capture detector (PDM-ECD) in 10% argon-inmethane buffer gas at atmospheric pressure and 125 °C. ...

The PDM-ECD kinetic method demonstrated above is expected to be applicable to any IM reaction where (1) the reactant ion can be generated by a thermal electron capture reaction, (2) the neutral reactant does not react significantly with thermal electrons, and (3) either the reactant or the product negative ion possess a uniquely high PD cross section in some region of the UVA is/near-IR spectral range between 250 and 1200 nm. ... 

Figure 5. The photodetachment spectra of Az measured by the photodetachment-modulated electron capture detector (PDM-ECD) in 10% argon-in-methane buffer gas at three different temperatures.

BSA LIF, MALDI-MS ECD, SPR PDMS, glass, fused silica, PMMA-CD, polycarbonate 100 fM [56,58,69-74]... 

Dopamine SVD, ECD, LIF PMMA, glass PDMS, quartz, glass 60 nM [61,62,87-89]... 

Abbreviations AOD, Acousto-optical deflection BCB, bisbenzyocyclobutadiene CCD, indirect contact conductivity detection CL, chemiluminescence ECD, electron capture detector FCS, fluorescence correlation spectroscopy FRET, fluorescence resonance energy transfer ICCD, integrated contact conductivity detection GMR, giant magnetoresistive LED-CFD, light emitting diode confocal fluorescence detector LIF, laser-induced fluorescence LOD, limit of detection MALDI, matrix-assisted laser desorption ionization PDMS, poly(dimethylsiloxane) PMMA, poly(methylmetha-crylate) SPR, surface plasmon resonance SVD, sinusoidal voltammetric detection TLS, thermal lens spectroscopy. 

Abbreviations DNA, deoxyribose nucleic acid ECD, electrochemical detection LIF, laser induced fluorescence LOD, limit of detection PDMS, poly(dimethylsiloxane) PSA, prostate specific antigen TOF-MS, time-of-flight mass spectrometer TNT, 2,4,6-trinitrotoluene. 

Phthalates have also been analysed by SPME-GC using an ECD detector. Prokupkova et al. studied different SPME parameters including two fibers PDMS and PA. PA extraction at room temperature for 20 min was the experimental condition selected. Samples were stirred during extraction. Desorption was performed at 250°C for 50 min to minimize carryover. Quantification was based on calibration curves for distilled water after subtraction of blanks. 

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