Amperometric detection IPAD

Figure 4 Typical potential step sequence in (A) pulsed amperometric detection (PAD) and (B) integrated pulsed amperometric detection (IPAD) of peptides.

Figure 4.2 Usual potential waveforms employed in PAD [22, 32], (a) Triple-pulse PAD, (b) quadruple pulse PAD, and (c) triangular scan integrated pulsed amperometric detection (IPAD), fjg, detection potential oxidation potential for electrode conditioning E,, reduc-...

Optimized Integrated Pulsed Amperometric Detection (IPAD) Waveform for Thiocompounds and Summary of Parameter Functions... 

Figure 8.127 Isocratic separation of giucose, fructose, and sucrose with integrated puised amperometric and MS detection. Separator coiumn CarboPac PA200 coiumn dimensions 250 mm x 3 mm i.d. eiuent 60 mmoi/L NaOH flow rate 0.5 mL/min detection IPAD and ESI-...

HPCEC, High-performance cation exchange chromatography IPAD, Integrated pulse amperometric detection ISWD,... 

RP-HPLC, reversed-phase HPLC IPAD, integrated pulse amperometric detection Au, gold working electrode pSPE, pre-anodlzed screen printed electrode. 

Summary of the Analytical Figures of Merit Achievable with High-Performance Liquid Chromatography with Integrated Pulsed Amperometric Detection (HPLC-IPAD). These Data were Collected by Injecting Each Compound Separately with a Mobile Phase Chosen to Yield Similar k Values for Each Compound... 

FIGURE 10.17 Detection of thiocompounds in various samples by High-performance anion-exchange chromatography with integrated pulsed amperometric detection (HPLC-IPAD). Samples were (A) grapefruit juice, (B) watermelon, and (C) chicken liver. Condition Ci8, 1-mm SepStik column 99.6% 100 mM phosphate buffer (pH 3)/0.4% acetonitrile 65 p,L/min 0.5 p,L injection volume and detection, IPAD waveform in Table 10.3. Peaks a, GSH b, methionine and c, GSSG. (Reprinted from LaCourse, W.R. and Owens, G.S., Anal. Chim. Acta, 307, 301, 1995. With permission.)... 

It is used in IC systems when the amperometric process confers selectivity to the determination of the analytes. The operative modes employed in the amperometric techniques for detection in flow systems include those at (1) constant potential, where the current is measured in continuous mode, (2) at pulsed potential with sampling of the current at dehned periods of time (pulsed amperometry, PAD), or (3) at pulsed potential with integration of the current at defined periods of time (integrated pulsed amperometry, IPAD). Amperometric techniques are successfully employed for the determination of carbohydrates, catecholamines, phenols, cyanide, iodide, amines, etc., even if, for optimal detection, it is often required to change the mobile-phase conditions. This is the case of the detection of biogenic amines separated by cation-exchange in acidic eluent and detected by IPAD at the Au electrode after the post-column addition of a pH modiher (NaOH) [262]. 

Figure 10.297 Separation of neomycin B from KOH (EG) flow rate 0.5 mUmin detection its impurities with integrated amperometric IPAD injection volume 20pL sample detection. Separator column CarboPac PA1 0.5 mg/mL neomycin B peaks (1) void, column dimensions 2S0mmx4mm i.d. col- (2)-(12) impurities,and (13) neomycin B. umn temperature 30 °C eluent 2.4mmol/L...

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