University of North Florida
Browse the Citations
-OR-

Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

View Stuart Chalk's profile on LinkedIn

Pawel Koscielniak

Abbrev:
Koscielniak, P.
Other Names:
Address:
Department Analytical Chemistry, Jagiellonian University, P. L. Krakow Poland
Phone:
NA
Fax:
(48-12) 634 05 15

Citations 13

"Flow System For Calibration And Interference Examination In Two-component Analysis"
Lab. Rob. Autom. 2000 Volume 12, Issue 5 Pages 228-235
Pawel Koscielniak, Malgorzata Herman

Abstract: The next flow system with fully rotary valve (FRV) has been designed and applied for calibration purposes in chemical analysis. In the present case the system was aimed at performing two-component analysis, namely, at preparing the set of two-component standard solutions and using them for calibration and determination of both components in a sample. It has been proven that the FRV, if suitably configured and operated, was capable of using only two initial standards for preparation of eight two-component solutions and furthermore, of composing them in accordance with the incomplete 32 experimental plan. Owing to that, the mathematical models then formulated on the basis of measurement data could serve not only for estimation of the concentrations of both analytes in a sample, but also for evaluation and elimination of the mutual influences between them. It has been experimentally revealed that the system developed allows the calibration procedure to be performed with low consumption of time, work, and reagents, providing reliable analytical results and valuable information about interferences.

"Flow Calibration System With The Use Of Fully Rotary Directive Valve"
Lab. Rob. Autom. 1999 Volume 11, Issue 2 Pages 111-119
Pawel Kóscielniak*, Malgorzata Herman, Joanna Janiszewska

Abstract: The flow system with fully rotary valve (FRV) operated as a directive valve has been designed and applied for calibration purposes. The role of the FRV was to create the set of standard solutions of compositions desired by directing and merging the streams of a single initial standard solution inserted into a flow manifold. The idea is presented of how different numbers of standards with the analyte concentrations distributed variously along a calibration line are possible to be prepared. It has been experimentally revealed that the system developed allows one to perform the calibration procedure with low consumption of time, work, and reagents, providing accurate and precise analytical results.

"Design Of The Fully Rotary Valve For Calibration Purposes In Flow Analysis"
Lab. Rob. Autom. 1997 Volume 9, Issue 2 Pages 47-54
Pawel Koscielniak*, Joanna Janiszewska

Abstract: Design of the fully rotary valve (FRV) that has been developed in our laboratory as a part of a manifold of flow analysis is presented. It can serve as both a directive and an injection valve. In both versions, it can be used for various calibration purposes that can make analytical procedures simpler, faster, and more effective. In this report, some concepts are described that allow one to perform a single-component analysis with the use of a single standard solution.

"Flow System From Analytical Calibration By The Integrated Method"
Instrum. Sci. Technol. 2002 Volume 30, Issue 3 Pages 251-266
Pawe&#; Koscielniak, Joanna Kozak, Ma&#;gorzata Herman

Abstract: The flow system has been designed for the purpose of performing analytical determinations according to the integrated calibration method. The system is equipped with a fully rotary valve which serves in preparation of the set of standard solutions from a single stock solution. A standard is exposed to measurements in two forms: by itself, and as a mixture with a sample. Each of the two solutions is able to be propelled to the detector at two different flow rates. As a consequence, the measurement information gathered during a single calibration run permits calculation of several estimations of an analytical result, in both the interpolative and extrapolative manner. Since some estimations are independent of each other, the final result is reliable in terms of accuracy, more than if using a conventional calibration approach. Owing to the instrumental simplicity and analytical efficiency, the system is expected to be useful for routine analysis.
Calibration

"Review Of Univariate Standard Addition Calibration Procedures In Flow Analysis"
Crit. Rev. Anal. Chem. 2006 Volume 36, Issue 1 Pages 27-40
Pawelstrok Kosacutecielniak; Joanna Kozak

Abstract: The calibration procedures related to the standard addition method and used in flow analysis are critically reviewed. All examples met in the literature are considered with respect to their facilities for overcoming the interferences. It is disclosed that the flow techniques give a chance to add the standard(s) to a sample by different manners allowing the analytical result to be calculated by either interpolative or extrapolative way. However, from among various calibration procedures those of extrapolative character are distinguished as they are exclusively able to compensate the multiplicative interference effect in wide range of the interferent(s) concentration. It is also shown how the flow standard addition approaches can be employed to solve different analytical problems and - on the other hand - why some of them reveal limited usefulness for calibration purposes. The particular groups of calibration procedures are compared with each other and discussed in terms of their analytical performance. Copyright © Taylor and Francis Group, LLC.

"Review And Classification Of Univariate Interpolative Calibration Procedures In Flow Analysis"
Crit. Rev. Anal. Chem. 2004 Volume 34, Issue 1 Pages 25-37
Pawel Koscielniak; Joanna Kozak

Abstract: A novel classification system introducing three main categories of the calibration methods - interpolative, extrapolative, and indicative - is suggested once more to be used in analytical chemistry. Then the univariate interpolative calibration procedures developed in the flow analysis are reviewed. In contrast to other similar reports, the present article does not present them with respect to instrumental aspects but as to how the measurement data recorded are interpreted and transformed into the analytical results. On such a basis, five groups of the calibration approaches have been specified. Finally, the particular groups of methods are compared with each other and discussed in terms of their analytical performance.

"A Critical Look At The Interpolative Standard Addition Method"
Analusis 1996 Volume 24, Issue 1 Pages 24-27
P Koscielniak

Abstract: The cited method (ISAM; Tyson, Anal. Proc., 1981, 18, 542) is compared theoretically and experimentally with conventional FIA AAS calibration procedures. Experimental results for the determination of Mg in the presence of the interferent Al show that ISAM is not as effective as conventional calibration procedures in eliminating interference effects. The use of ISAM is not recommended in general. It may be useful in process control procedures in which the interferent produces a constant effect but conventional calibration methods will give better precision and require a smaller amount of sample.
Magnesium Spectrophotometry Interferences

"Simple Flow Injection Titration Method Based On Variation Of The Sample Volume"
Anal. Lett. 2002 Volume 35, Issue 13 Pages 2145-2155
Pawelstrok Koscielniak; Joanna Kozak

Abstract: A simple single-line flow injection system incorporating the fully rotary valve (FRV) has been developed for titration purposes. The FRV enables to inject the titrand solution to the titrant stream in four different volumes producing a set of four adequate analytical signals. Due to this fact the titration procedure can be performed with the use of only two standard solutions which allow four parallel calibration lines to be constructed. The method was tested on the example of spectrophotometric acid-base titration. Under optimized flow conditions (flow rate of 8.3 mL/min, the volumes injected of 30, 100, 300, and 800 µL, titrant containing 0.1 mmol/L NaOH and 4 x 10^-4% bromothymol blue) the analytical results of precision less than 0.6% (RSD) and of accuracy less than 0.5% (relative error) were obtained for the HCl samples of pH ranged from 1 to 2.

"A New Approach To The Integrated Calibration In Flow Injection Analysis"
Ann. Chim. 2003 Volume 93, Issue 12 Pages 1045-1058
P. Koscielniak, G. Akcin, M. Herman, J. Kozak, M. Wieczorek

Abstract: A new proposal how to perform the analytical procedure according to the integrated calibration method is presented. An original flow injection system has been designed for this purpose. When using only a single standard solution, the measurement information gathered during a single analytical course permits construction of four calibration graphs and calculation of as many as four independent estimations of the analyte concentration in the sample examined. As the calibration method applied integrates the set of standards method and the standard addition method, the analytical estimations may be obtained in both the interpolative and the extrapolative manner and the final result can be effectively verified in terms of accuracy. The system developed was experimentally tested on the example of spectrophotometric determination of chromium. It has been proved to be capable of saving time and reagents as well as providing reliable analytical results. Owing to the instrumental simplicity and analytical efficiency the system is expected to be useful for routine analysis.

"Calibration By The Gradient Ratio-standard Addition Method In Flow Injection Flame Atomic Absorption Spectrometry"
Anal. Chim. Acta 2002 Volume 460, Issue 2 Pages 235-245
Paweł KoŞcielniak and Joanna Kozak

Abstract: A calibration method has been developed which is realised in the flow injection analysis (FIA) by the gradient technique. According to this method two transient peaks, one for a sample and the other for a sample with standard addition, are recorded and compared point by point in the entire defined time range. The analytical result is estimated on the basis of information gained about the local analyte concentrations in the sample zone. The method allows the results to be reliable when both the non-linear calibration dependence and the interference effect occur. As an example, calcium in synthetic samples containing silicon, phosphate, aluminum, vanadium and titanium, and also in iron ore sample, were determined by flame atomic absorption spectrometry (FAAS). It has been proved, that the method can be effective in overcoming even extremely strong interferences, providing analytical results with average accuracy equal to ~5% and with precision 2-3 times inferior to that obtained by conventional FI calibration. (C) 2002 Elsevier Science B.V. All rights reserved.
Calibration

"Univariate Calibration Techniques In Flow Injection Analysis"
Anal. Chim. Acta 2001 Volume 438, Issue 1-2 Pages 323-333
Pawel Koscielniak

Abstract: A critical view of univariate calibration techniques developed in the flow injection analysis (FIA) is presented. A classification system based on three main calibration categories - interpolative, extrapolative or indicative - is proposed and rationale behind it discussed. Then, the reasons for rather poor applicability of FIA techniques to routine analysis are considered from various points of view. Finally, a novel approach to the FIA calibration is suggested: the integrated calibration technique. It is believed to be more acceptable in analytical practice due to such features (discussed theoretically and shown experimentally) as reliability, simplicity, versatility and procedural similarity to the common batch calibration technique.

"Examination Of Interferences In Flame Atomic Absorption Spectrometry Using A Flow Injection Technique"
Anal. Chim. Acta 2001 Volume 438, Issue 1-2 Pages 187-194
Paweł KoŞcielniak and Marek Kozak

Abstract: Interference effects were examined in FAAS by means of specific measurement of flow injection peaks. In each given case, a single Fl peak was examined - those parameters which define the inflection points were measured. Parameters characterising a common region of two parts of a double FI peak were also taken into consideration. The interferences were studied using the example of tested samples containing calcium in the presence of aluminum and phosphates. It was revealed that the parameters considered can be measured with very good precision allowing one to detect even slight peak deformations caused by interferences. Among the approaches applied, one using a double peak appeared to be most sensitive and reliable. It has been also noticed that the inflection points of an FI peak may play a special role in the interference examinations.

"Calibration Procedure For Flow Injection Flame Atomic Absorption Spectrometry With Interferents As Spectrochemical Buffers"
Anal. Chim. Acta 1998 Volume 367, Issue 1-3 Pages 101-110
Pawe

Abstract: The flow injection calibration procedure was developed to correct for interferences in flame atomic absorption spectrometry. For this purpose a sample and standard solutions were injected one after the other into the carrier stream containing some reagents known to usually produce strong interference effects. Affecting the analyte in both zones to the same extent they were able to act as spectrochem. buffers. As an example, calcium in synthetic samples containing aluminum, titanium and vanadium, and also in iron ore samples, was determined The procedure appeared to be quite effective in overcoming interferences even as strong as nearly 90%, providing anal. results with average accuracy equal to ~5%. Precision attained was 2-3 times inferior than that obtained using conventional FI calibration.
Calcium Iron Spectrophotometry Interferences Standard additions calibration Method comparison