4th EucheMs chemistry congress

Poster Session 2
s1141
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - Analytical Chemistry
P - 0 5 5 8
deterMinAtion PKA vALueS of AntifunGAL
druGS By uv SPeCtroSCoPiC Method
n. SAnLi 1 , f. BASArAn 2 , S. SAnLi 1 , n. CoLAK 2
1 Usak University, Chemistry, Usak, Turkey
2 Hitit University, Chemistry, Corum, Turkey
Email: nurullahsanli@gmail.com
Dissociation constants (pK values) are useful
a
physicochemical parameters describing the extent of ionization
of functional groups with respect to pH. The knowledge of pK is a
important in drug discovery and development since the
pharmacokinetic and pharmacodynamic properties of different
protonation/ionization forms of the drug molecules may vary
considerably [1] .
In this study, the acidity constants of eight antifungal drugs
(fenticonazole, isocanozole, itracanozole, ketocanozole,
mikanozole, ornidazole, tinidazole, tiocanozole) have been
determined in water and 10–20 % (v/v) MeCN-water mixtures at
(25.0 ± 0.1) °C and in 0.1 mol L-1 KCl by UV spectroscopic
method. Datas were processed using the program STAR (Stability
Constants by Absorbance Readings) which calculates stability
constants and molar absorptivities of the pure species by multi
linear regression [2] .
references:
1. P. J. Taylor, “Hydrophobic Properties of Drugs”.
In C. Hansch, P.G. Sammes, J.B. Taylor, (Eds.),
Comprehensive Medicinal Chemistry, Vol. IV;
Pregamon Press: Oxford, 1990; pp. 241-294.
2. J. L. Beltran, R. Codony, M. D. Prat, Anal Chim Acta
1993, 276, 441–454.
Keywords: Analytical methods; Antiviral agents; Drug design;
Solvent effect; UV/Vis spectroscopy;
4 th EucheMs chemistry congress
P - 0 5 5 9
iMPortAnCe of evALuAtinG the fALSe
non-CoMPLiAnCe And fALSe CoMPLiAnCe in
the deterMinAtion of the MiniMuM
ContentS of Protein, dry MAtter And the
rAtio fAt dry MAtter in zAMorAno CheeSe
when A nir-PLS ProCedure iS uSed
M. L. oCA 1 , M. C. ortiz 1 , L. SArABiA 2
1 University of Burgos (Faculty of Sciences)), Analytical
Chemistry, Burgos, Spain
2 University of Burgos (Faculty of Sciences)), Mathematics and
Computation, Burgos, Spain
Nowadays, near-infrared (NIR) spectroscopy means a useful
methodology in process monitoring, determination of quality,
geographical origin and adulteration of dairy products. However,
because of the changes in spectra caused by various physical
properties, a calibration against a reference method for the
constituent of interest is required. Generally, a Partial Least
Squares (PLS) regression is applied. The compliance of a
maximum or a minimum limit for the quantity of a substance in
food is mandatory in many of these determinations. So assessing
the efficiency of NIR-PLS procedures in terms of detection
capability (CDβ) evaluating the probabilities of false
non-compliance (α) and false compliance (β) is needed.
This work was aimed to develop a rapid analytical tool for
monitoring simultaneously the contents of fat, dry matter, protein
and the ratio fat/dry matter in Zamorano cheese samples by NIR
spectroscopy. Zamorano cheese is protected with a Designation
of Origin and registered as Protected Designation of Origin, which
represent the system of recognition of a distinctive quality within
the European framework. Calibration models based on a PLS
regression of the percentage in weight of every constituent on the
spectra recorded were estimated. Therefore, values of the
explained variance of the response between 92.54 and 96.57%
were obtained, and the mean and the standard deviation of the
absolute value of the relative error in calibration ranged
from 0.66 to 1.05% and from 0.43 to 0.87%, respectively.
The trueness of every method was also ensured, and the minimum
contents of protein, dry matter and the ratio fat/dry matter
according to specific regulations were calculated.
Experimental values of CDβ equal to 24.57% for protein,
53.28% for dry matter and 43.78% for the ratio fat/dry matter
were obtained (α=β=0.05)
Acknowledgements: financial support through projects
CTQ2011-26022 and BU108A11-2. M.L. Oca thanks to
University of Burgos for her FPI grant.
Keywords: NIR; Partial Least Squares; Cheese; False
compliance; Capability of detection;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc