4th EucheMs chemistry congress

Poster Session 2
s1144
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - Analytical Chemistry
P - 0 5 6 4
PotentioMetriC deterMinAtion of
PiroxiCAM in Pure And PhArMACeutiCAL
doSAGe forMS
n. PeJiC 1 , n. SArAP 2 , J. MAKSiMoviC 3 ,
S. BLAGoJeviC 1 , L. KoLAr-AniC 3 , S. AniC 4
1 University of Belgrade Faculty of Pharmacy, Department of
Physical Chemistry and Instrumental Methods, Belgrade,
Serbia
2 Institute of Nuclear Science Vinca, Radiation and
Environmental Protection Department, Belgrade, Serbia
3 University of Belgrade Faculty of Physical Chemistry,
Department of Dynamic and Structure of Matter, Belgrade,
Serbia
4 University of Belgrade Institute of Chemistry Technology and
Metallurgy, Department of Catalysis and Chemical
Engineering, Belgrade, Serbia
Different analytical methods for determination of piroxicam
(PX) in various real samples were summarized in [1] . However,
some new methods based on relatively simple and inexpensive
equipment were desirable. Regarding that, the method based on
employing the analyte pulse perturbation technique to the
Bray-Liebhafsky (BL) oscillatory reaction as very nonlinear
system, as well as using the potentiometric monitoring of analyte
perturbation, promise the alternative to some instrumental
methods due to its low cost instrumentation and relatively rapid
detection procedure.
For quantitative determination of PX [2] , the BL matrix in a
stable non-equilibrium stationary state that was generated in
continuously fed well stirred tank reactor, was used. The BL matrix
response to perturbations by different concentrations of PX is
followed by a Pt electrode. The method relies on the linear
relationship between maximal potential shift, ΔE m , and the added
PX concentration in the range of 6.8 x 10 –5 –1.9 x 10 –3 mol L –1 . Under
the optimized conditions (T=64.0°C, [H 2 SO 4 ] 0 =8.55x10 -2 mol L -1 ,
[KIO 3 ] 0 = 5.90x 10 -2 mol L -1 , [H 2 O 2 ] 0 = 1.50 x10 -1 mol L -1
and j 0 =2.95x10 -2 min -1 ), the regression equation of the standard
series calibration curve is ΔE m =-5.9 - 14671.9 x c PX . The method
has a rather good sample throughput of 30 samples h -1 with the limit
of detection LOD =6.3x 10 –5 mol L –1 , precision RSD =4.2 %, as
well as recoveries RCV ≤ 104.7 %. Applicatibility of the proposed
method to the direct determination of PX in different
pharmaceutical formulations (tablets, ampoules and gel) was
demonstrated.
references:
1. M. Starek, J. Krzek, Talanta, 2009, 77, 925.
2. V. Vukojevic, N. Pejic, D. Stanisavljev, S. Anic,
Lj. Kolar-Anic, Analyst, 1999, 124, 147.
Keywords: piroxicam; potentiometric; oscillatory reaction;
4 th EucheMs chemistry congress
P - 0 5 6 5
deterMinAtion of diffuSion CoeffiCientS By
tAyLor diSPerSion AnALySiS uSinG CAPiLLAry
eLeCtroPhoreSiS inStruMentAtion with
vAriouS deteCtorS
J. Petr 1 , P. GinterovA 1 , r. KnoB 2 , J. znALezionA 1 ,
v. MAier 1 , J. SevCiK 2
1 Regional Centre of Advanced Technologies and Materials
– Palacky University in Olomouc, Department of Analytical
Chemistry, Olomouc, Czech Republic
2 Palacky University in Olomouc, Department of Analytical
Chemistry, Olomouc, Czech Republic
Determination of diffusion coefficient represents an
important task for many branches of the research ranging from
pure physical chemistry to medicine where the diffusion of
pharmaceutical active substances has an impact on the physiologic
state of organism. There a plenty of methods used for such
measurements. A special place is hold by capillary electrophoresis
(CE). CE represents a fast, low cost, easy operation technique that
needs only a few microliters of samples. On the basis of the Taylor
and Aris theory, CE can be utilized for the measurements of the
rate of the diffusion during the flow of compounds through the
capillary. The aim of our work was to apply this methodology,
called Taylor dispersion analysis (TDA), for measurements of the
diffusion coefficient of model compounds employing various
detectors that have an additional power (e.g. can be applied for
UV non-absorbing compounds, provides structural information).
In our study, three types of detectors were used: (i) contactless
conductivity detector for analysis of some saccharides,
(ii) laser-induced fluorescence detector for analysis of carbogenic
quantum dots, and (iii) single quadrupole mass spectrometer for
analysis of a mixture of aminoacids. We observed that the
utilization of such detectors can be very profitable for the
determination of diffusion coefficients.
Acknowledgement: The financial support by the
KONTAKT project LH11018, the Operational Program
Research and Development for Innovations – ERDF
(project CZ.1.05/2.1.00/03.0058), and the Operational
Program Education for Competitiveness – ESF (project
CZ.1.07/2.3.00/20.0018) is gratefully acknowledged.
Keywords: diffusion coefficient; capillary electrophoresis;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc