Some Metrological Aspects of the Optimization of Thermal-Lens Procedures

Проскурнин, М. А.; Chernysh, V. V.; Филичкина, В. А.

doi:10.1023/b:janc.0000040695.95051.be

Cited by 15 publications

(14 citation statements)

References 10 publications

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“…This led us to the conclusion that the sample preparation step makes a major contribution to the total measurement error. Of importance is the fact that the values of s rep for TLM were even lower than those for TLS (for three of four cases), which means that the flow reactions in TLM proves an even lower sample-preparation error than standard photometric procedures used in TLS [11].…”

Section: Simple Variance Analysis Of the Results Of Analytical Determmentioning

confidence: 81%

“…We selected water, ethanol, and 1-butanol as the most accepted solvents in microfluidic applications. The data for TLS were selected from our previous paper [11]. For TLM, a combination of the data obtained (63 measurements of the average signal) gave the normal distribution for both microscopes used (Fig.…”

Section: Normal Distribution Of the Results Of Thermallens Measurementsmentioning

confidence: 99%

“…In our previous reports devoted to the instrumentation of thermal lensing, we showed that the combined use of the data on accuracy and precision of thermal lensing [11] and specific features of the reactions at the nanogram level enhances the sensitivity and selectivity of procedures. We also found that crossed-beam TLS (CB-TLS), the most accepted photothermal-detection technique in capillary electrophoresis [12], and TLM [7,13] have differences in appara-tuses, but have the same advantages of chemistry at the trace level.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Thermooptical detection in microchips: From macro‐ to micro‐scale with enhanced analytical parameters

Smirnova¹,

Проскурнин²,

Bendrysheva³

et al. 2008

Electrophoresis

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In this paper, we compared the methods of photothermal spectroscopy used in different spatial scales, namely thermal-lens spectrometry (TLS) and thermal-lens microscopy (TLM) to enhance the performance parameters in analytical procedures. All of the experimental results were confirmed by theoretical calculation. It was proven that the design for both TLM and TLS, despite a different scale for the effect, is governed by the same signal-generating and probing conditions (probe beam diameter at the sample should be equal to the diameter of the blooming thermal lens), and almost does not depend on the nature of the solvent. Theoretical and experimental instrumental error curves for thermal lensing were coincident. TLM obeys the same law of instrumental error as TLS and shows better repeatability for the same levels of thermal-lens signals or absorbances. TLS is more advantageous for studying low concentrations in bulk, while TLM shows much lower absolute LODs due to better repeatability for low amounts. The behavior of the thermal-lens signal with different flow rates was studied and optimum conditions, with the minimum contribution to total error, were found. These conditions are reproducible, are in agreement with the existing theory of the thermal response in thermal lensing, and do not significantly affect the design of the optimum scheme for setups. TLM showed low LODs in solvent extraction (down to 10(-8) M) and electrokinetic separation (10(-7) M), which were shown to be governed by discussed instrumental regularities, instead of by microchemistry.

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Section: Simple Variance Analysis Of the Results Of Analytical Determmentioning

confidence: 81%

Section: Normal Distribution Of the Results Of Thermallens Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermooptical detection in microchips: From macro‐ to micro‐scale with enhanced analytical parameters

Smirnova¹,

Проскурнин²,

Bendrysheva³

et al. 2008

Electrophoresis

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“…Finally, because the sensitivity coefficient (calibration slope) and LOD are governed by different factors, mainly the sensitivity and reproducibility, 14,15,55,56 we compared the photothermal procedures by the minimum value of the reproducibility RSD and by the SE ratio, Eq. (5), which highlights changes in the reproducibility.…”

Section: Comparison Parametersmentioning

confidence: 99%

“…14 Moreover, simultaneous consideration of the accuracy of TLS and reaction conditions at the nanoscale level also enhances the selectivity. 15 However, the dependence of the TLS sensitivity on the thermophysical properties of the solution poses a problem: What is more important, an increase in the strength of the photothermal effect (photothermal sensitivity) or an increase in the analytical sensitivity due solvent selection as a chemical component? From the viewpoint of photothermal sensitivity, the best are nonpolar organic solvents, 2,16,17 which can be used in extraction procedures and preconcentration.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Performance Parameters of Photothermal Procedures in Homogeneous and Heterogeneous Systems

et al. 2011

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The main types of analytical procedures used in thermal-lens spectroscopy and microscopy, which are based on photometric reactions in (i) aqueous solutions, (ii) organo-aqueous mixtures, (iii) polymer-containing (nonionic surfactants or polyethylene glycol) aqueous solutions, (iv) water-organic extraction systems, and (v) two-phase aqueous extraction systems, were compared from the viewpoint of both reproducibility and sensitivity. This comparison was made by examples of the determination of cobalt and iron for batch conditions, flow determination, and detection in HPLC, flow-injection analysis (FIA), and μFIA. It was revealed that for all five types, the real analytical efficiency (a decrease in the limit of detection (LOD) as compared to spectrophotometry) is primarily determined by the reaction conditions, provided that excitation of the thermal lens is the same. Aqueous solutions provide more efficient optimization of reaction conditions than do those in organo-aqueous solutions and solvent-extraction water-organic mixtures. The best results are achieved when shifting to polymer-containing aqueous solutions and two-phase aqueous extraction systems, which decreases in the LODs by a factor of 20 -100%.

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Analytical Measurement and Data Processing Considerations

2019

Photothermal Spectroscopy Methods

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Some Metrological Aspects of the Optimization of Thermal-Lens Procedures

Cited by 15 publications

References 10 publications

Thermooptical detection in microchips: From macro‐ to micro‐scale with enhanced analytical parameters

Thermooptical detection in microchips: From macro‐ to micro‐scale with enhanced analytical parameters

Comparison of Performance Parameters of Photothermal Procedures in Homogeneous and Heterogeneous Systems

Analytical Measurement and Data Processing Considerations

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