4th EucheMs chemistry congress

Poster Session 2
s1157
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - Analytical Chemistry
P - 0 5 9 0
SiLiCon deterMinAtion in niCKeL
SuPerALLoyS By iCP-AeS Method
M. yAKiMovA 1 , f. KArAChevtSev 1 ,
t. zAGvozdKinA 1 , r. dvoretSKov 1
1 All-Russian Scientific Research Institute of Aviation Materials,
Laboratory “Spectrum chemico-analytical researches and
standard specimens”, Moscow, Russia
Silicon is impurity in heat-resistant Ni alloys such as Inconel
and determinate in ranges from 0,001 to 0,2 % wt, whereas at Si
content from 0,5 to 2 % wt silicon reduce erosion. In nickel
brazing (Solbraz, Nicrobraz, Colmonoy) silicon exclude erosion
of brazed alloy at Si content more than 5 % wt.
This work deals with of method of sample preparation and
test method of Si analysis from 0,001 to 10 % wt in Ni alloy by
using ICP-AES method.
It’s known Si with HF forms volatile compound SiF ; under
4
the influence of HF Si is washed away from glass spray system
of spectrometer; Si is adsorbed on plastic spray system of
spectrometer; in mixture of HCl and HNO3 silicon precipitate into
silica sol (H SiO ) . Therefore two ways of a sample preparation
2 3 n
and determination of silicon were offered.
The first way consists in alloy dissolution in the minimum
quantity of chlorazotic acid diluted with water in ratio 1:10. The
second way consists in alloy dissolution in the minimum quantity
of a mixture of H O, HCl, HNO , HF (in ratio 10:3:1:1). Alloy
2 3
samples are dissolved by using microwave digestion system
MARS5. Measurements of Si content carried out on ICP-AES
spectrometer VARIAN 730 ES in reference materials. At first way
quartz spray system was used, at second - fluoroplastic spray
system, a plastic spray.
It’s shown that this way allows to determinate silicon in a
range from 0,001 to 3 % wt with error no more than 3 % relative
by using first way and in a range from 0,1 to 10 % wt with an
error of no more than 5 % relative by second one.
The proposed ways of Si analysis can be successfully
applied in the silicon determination in alloys based on iron, cobalt,
titanium, copper, etc.
Keywords: silicon analysis; ICP-AES; test method; Ni alloys;
4 th EucheMs chemistry congress
P - 0 5 9 1
SeLeCtive deteCtion of ProteinS in SdS-PAGe
AnALySiS
t. zAnni 1 , B. KÖniG 1
1 University of Regensburg, Institute of Organic Chemistry,
Regensburg, Germany
SDS-PAGE is a widely used technique when dealing with
biomacromolecules. The most used proteins detection techniques
nowadays in SDS PAGE analysis are Coomassie brilliant blue
stain and silver stain; both techniques allow to detect proteins in
gels with good sensitivity and reasonable time consumption.
When analysing complex mixture of proteins selectivity is often
desired. Even if well-established techniques are available for this
purpose (such as western blotting and post-translational
modifications selective probes), the development of new, cheaper
and faster methods to selectively detect proteins is of great
interest.
Several compounds showing affinity towards different kind
of functional groups which are present in amino-acids side chains
(e.g. phosphorylated sites [1] , imidazole ring [2] , carboxylates [3] )
have been reported in literature.The structure of such compounds
consists of Zn(II) or Cu(II) coordination complexes as recognition
moiety combined with a reporting fluorophore. Binding activity
leads to changes in fluorescence, such as variation of intensity or
emission wavelength shift, allowing detection.
By mean of the same strategy, we designed different
potential probes consisting of Zn(II) – cyclen complex covalently
linked to fluorescent dyes such as nile blue, hodamine B and eosin
Y. We are currently synthesizing such compounds, which will be
tested as probes for selective recognition of consecutive
negatively charged aminoacids sequences (e.g EE, DD, EED etc.)
in model proteins.
As different approach, we are going to use known specific
interactions between metal cations and given amino acid
sequences, followed by detection of bound cations (e.g by
colorimetric indicators). The detection of polihistidine-tagged
proteins by using the interaction with copper(II) cations is
currently under investigation.
references:
1. Riechers, A. et al. ; Bioconjugate Chemistry, 20, 804-807
(2009).
2. Stadlbauer, S. et al.; Chemistry-A European Journal 14,
2536-2541 (2008).
3. Bhuyan, M. et al. ;. European Journal of Organic
Chemistry 2011, 2807-2817 (2011).
Keywords: molecular recognition; electrophoresis; fluorescent
probes;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc