Sample modulation

Fig. 3.96. Schematic figure of membrane sampling modules from bioreactor coupled to HPLC-DAD. Reprinted with permission from A. Plum et al. [156].

A. Plum, G. Braun and A. Rehorek, Process monitoring of anaerobic azo dye degradation by high-performance hquid chromatography-diode array detection continuously coupled to membrane filtration sampling modules. J. ChmmatogrA, 987 (2003) 395-402. 

Figure 12. Sample modulation data of chemical amplifier of Cantrell et al. (130,), showing stability over a 1-h time period (top) and the time dependence on a shorter time scale (3 min).

Besides offering enhanced sensitivity, the vapor concentrator can also act as a sample modulator for baseline drift compensation. As illustrated in Figure 6.17 (page 389), the enriched vapor concentration discharged from the concentrator exhibits a characteristic maximum at a predictable time after the desorptimi cy-... 

Auother dust sampler that uses a haud-held vacuum cleaner but is capable of collectiug large dust samples was desigued by Rudel et al. (2001). The method employs a Eureka Mighty-Mite vacuum cleaner (8 A) (The Eureka Company, Bloomington, IL, USA) with the dust bag replaced by a 19-uun x 90-mm cellulose Soxhlet extraction thimble contained in a special PTFE sampling module. 

The volume-sampling module (Module 4) consists of three submodules. The purpose of submodule 4.1 is the gas suction or pump (not needed in pressurised gasification). In the. submodule 4.2 a gas meter measures the volume of gas flow. Additionally a flow meter, a pressure indicator and a temperature indicator are needed. 

Analyses of inorganic and organic carbon were made on dry sediment samples by combustion on a Shimadzu TOC-5000 total organic carbon analyzer equipped with a solid sample module SSM-5000A. 

Thus, the recorded signal corresponds to the integral of the excess minority carrier profile throughout the sample modulated by the relative carrier mobilities. This finding was the basis for the analysis of the charge transfer and surface recombination velocity profiles above (cf Figures 2.16 and 2.17). 

S.L. Daniel, J.N. Ngunjiri, and J.C. Gamo, Investigation of the magnetic properties of ferritin by AFM imaging with magnetic sample modulation. Aruil. Bioanal. Chem., 394, 215-223 (2009). 

FIA analyzers or FIA components. One company produces a series of instruments that are flow injection systems with atomic absorption spectrometric detection dedicated to determination of mercury. Some companies produce flow injection analyzers for a large number of ions. One supplier has an analyzer that comprises three separate units a basic analytical module, an automatic sample module, and a data capture module, all these units being completely automated. The instrument is capable of analyzing nutrients, ions, and metals. It offers a wide analytical choice using ion-selective electrodes (ISEs), chemiluminescence, or fluorescence. With analysis speeds up to 120 samples per hour and detection limits down to parts per billion levels, this flow injection analyzer performs determinations well compared with other techniques. 

The SPIA amplification product can be cleaned up using the GeneChip sample module as deseribed previously, with only the few modifications that follow. 

R. U. Seidel, et al, Capilary Force Mixing Device as Sampling Module for Chemical Analysis, in Proceeding of Transducers 99 Sendai, 1999, 438-441. 

Ovemey, F.L., Enke, C.G. (1996) A mathematical study of sample modulation at a membrane inlet mass spectrometer—potential application in analysis of mixtures. Journal of the American Society for Mass Spectrometry, 7, 93-100. 

A d.c. voltage was applied to the polyacetylene gap, which acts as a pulser upon excitation and biases the second gap. The quantity measured is the total charge at the output of the Si gap as a function of the relative delay between the two light pulses. The signal was amplified with a broadband preamplifier and integrated with a fast-sampling module of a boxcar system. 

The sample-tip-cantilever system can be modeled as a mechanical system with springs and dash-pots 11,12). Solving the motion equations of this model at low frequency (i.e. below the cantilever resonance frequency) and neglecting the damping constants (i.e. neglecting viscoelastic effects in polymers) leads to the following relation for the ratio between the sample modulation amplitude, z, and the tip response amplitude, also called the dynamic elastic response ... 

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