The review deals with soft ionization mass-spectrometry use in retrospective toxicological analysis of highly dangerous toxicological. Advantages and disadvantages of LC-MS and MALDI-MS in detection of both toxic agents and biomarkers of intoxication are described.

*Institute for Analytical Instrumentation RAS, Saint-Petersburg **Research Institute of Hygiene, Occupational Pathology and Human Ecology, Saint-Petersburg

Using MX-5310 complex a method for quantitative evaluation of melamine content in milk products was de-veloped. Tris-buffer was used as a standard. Caliber curve was developed for the device. It allows to determine melamine content in milk products.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

A mass spectrometric method of serum amyloyd A (SAA) identification was developed. SAA is a protein, characteristic marker for ovarian cancer diagnostics. Its determination was accomplished directly in the human blood serum by regulated trypsinolysis without a preliminary separation. New approaches to quantitative deter-mination of this protein in blood sera with using of concentration of its tryptic fragment (67–87) SAA, present in hydrolysates, were developed. Besides mass spectrometric method of determination of α2-macroglobulin (α2-M) in blood sera and plasma were developed. Concentrations of α2-M in blood sera under ovarian cancer and in blood plasma under Alzheimer disease were measured using developed methods. It was shown that concentra-tion of α2-M significantly increases under ovarian cancer and decreases under Alzheimer disease relatively of donor’s blood sera.

*Institute for Analytical Instrumentation RAS, Saint-Petersburg **Oreсhovich Institute of Biomedical Chemistry RAMS, Moscow ***Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Mosсow ****The Hospital of RAS, Saint-Petersburg

New economical HPLC-method for cyclosporine A determination in patient blood serum has been proposed. Chromatography analysis was carried out on liquid chromatograph "Milichrom A02". For cyclosporine A peak identification and its homogeneity confirmation spectral ratios and on line LC-MS complex were used. The method allows determination of cyclosporine A in 100–400 ng/ml range with no more than 15 % error. Results of determination are used for therapeutic monitoring of cyclosporine A in oncology department of pediatric clinic.

*Limnological Institute SD RAS, Irkutsk **Institute for Analytical Instrumentation RAS, Saint-Petersburg

It is a well-known fact that organophosphates (OP) inhibit several major enzymes, and this fact can be easily proved by simple laboratory and clinical biochemistry methods. On the other hand, diagnostics of low dosed chronic OP action, or their delayed effects after subacute intoxication is a serious problem because of lack of in-hibition or recovery of the enzymes activity. Determination of peptide or serum blood plasma spectrum can serve an alternative and more sensitive method for intoxication diagnostics. In this paper, we demonstrate data on peptide spectra of rat plasma or serum after subchronic intoxication with Russian VX (RVX) in vivo, and that of human plasma or serum after human blood exposure to RVX in vitro. It is shown that the principal peptide plasma or serum component after RVX exposure is peptides derivatives of fibrinopeptide A, thus showing inac-tivation of exopeptidases under RVX exposure.

*Institute for Analytical Instrumentation RAS, Saint-Petersburg **Research Institute of Hygiene, Occupational Pathology and Human Ecology, Saint-Petersburg ***Institute for Cell Biophysics RAS, Pushchino ****Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Mosсow

The main products of the chiral 2-methyl-4(S)-isopropyl-2-oxazoline oxidation with urea-hydrogen peroxide combination in the presence of MeReO₃ is the corresponding ring-opened N-(2-hydroxiehtyl)acetamide. ESI-TOF mass-spectrometric analysis was used to identify this product in the complex reaction mixture. The main ion in MS-spectra corresponds to its dimmer with losing of water molecule.

*Saint-Petersburg State University, Chemical department **Institute for Analytical Instrumentation RAS, Saint-Petersburg

Calorimetric evaluation of МО₂(СF₃СОО)₄ and МО₂(СH₃СОО)₄ enthalpy of solution in HMPA and DMF has been performed. Using mass-spectrometry methods it has been established that formed adducts composition corresponds to formulas МО₂(RСОО)₄ •(HMPA)₂ and МО₂(RСОО)₄•(DMF)₂.

*Saint-Petersburg State University, Chemical department **Institute for Analytical Instrumentation RAS, Saint-Petersburg

A protein fraction of human blood serum exposed in vitro to sulfur mustard (bis-2-chloroethylsulfide, HD) has been studied using MALDI-TOF and ESI-TOF methods, and a number of HD-modified albumin peptides have been identified. A tryptic peptide with molecular mass of 2536.19 Da has been identified by MALDI-TOF and MALDI-TOF-TOF methods. In addition 3 modified chymotryptic peptides with molecular masses 838.37 Da, 1200.53 Da, 2378.13 Da were found with ESI-TOF method.

*Institute for Analytical Instrumentation RAS, Saint-Petersburg **Research Institute of Hygiene, Occupational Pathology and Human Ecology, Saint-Petersburg ***Institute for Cell Biophysics RAS, Pushchino ****Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow

Data on qualitative composition of aqueous stearic acid monolayer with the presence of Fe³⁺ ions were ob-tained by means of mass-spectrometry. Using these data monolayer surface properties were interpreted. Monolayers isothermal compression was studied and stearic group area in different pH conditions was calcu-lated. The main products of stearic acid monolayers interaction with Fe (III) are proved to be particles with two stearic groups. Similar results have been obtained for Cr³⁺ ions. These findings prove that steric factor prevents Me(St)₃ formation.

*Saint-Petersburg State University, Chemical Department, Saint-Petersburg **Institute for Analytical Instrumentation RAS, Saint-Petersburg

Using ESI-MS and MALDI-MS the process of isotope exchange of ¹⁶О for ¹⁸О in peptide carboxyl groups was studied. It was shown, that carboxyl group protonization is a limiting stage in this exchange. Protonization depends on carboxyl group acidity as well as acidity of the medium. Optimum conditions for the production of 18O-containing peptides and amino acid derivatives which can be used as standards for the quantitative analysis are determined. Stability of the introduced label in the conditions approaching physiological, and in media commonly used in experimental work with specimen using HPLC and ESI-MS was evaluated.

*Institute for Analytical Instrumentation RAS, Saint-Petersburg **FSU Research Institute of Physico-Chemical Medicine, Moscow ***Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Mosсow

Poly(N-acryloyl-11-aminoundecanoic acid) was synthesized via free-radical polymerization in micellar and molecular solution. The structures of polymerization products in dimethylformamide were elucidated from MALDI data; mechanisms of the above products formation are discussed.

*Saint-Petersburg State University, Chemical department **Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Mosсow ***Institute for Analytical Instrumentation RAS, Saint-Petersburg

A study of the interaction of selenium (Se) with elements of biological systems cysteine (Cys) and glu-tathione (GSH) as an example was performed. The study was carried out using complex which includes the liq-uid chromatograph Milichrom А02 and time-of-flight mass spectrometer with electrospray ionization МХ-5310, developed in the Institute for Analytical Instrumentations RAS. Result of this study was a new scheme of chemical reactions. Besides a possibility of the analytical complex to perform a research of a competitive inter-action of selenium and silver with sulfhydryl groups GSH was demonstrated.

*Institute for Analytical Instrumentation RAS, Saint-Petersburg **Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry RAS, Mosсow

This paper deals with the development of domestic nano-LC-MS analytical system. The main functional blocks of the system are chromatography installation based on HPLC micro column techniques, nano-ESI ioni-zation block and TOF analyzer. This system was realized on the bases of MX-5310 mass-spectrometer (IAI RAS). The article describes the main parameters of the developed system and compares them with those of do-mestic LC-MS systems. The developed system allows working with nano amounts of testing samples. Capillary column use as nano emitter increases quality of analysis and makes the system more economic in solvent con-sumption.

*Institute for Analytical Instrumentation RAS, Saint-Petersburg **Protein Interaction Laboratory, Center for Experimental Bioinformatics, University of Southern Denmark, Odense

The work presents a theoretical bases of a non-uniform electrostatic field application in the pulser of TOF mass-spectrometer. Using TOF mass spectrometer МХ-5303 developed in the Institute for analytical instrumen-tation of the Russian Academy of Sciences as an example, it was shown that monopole use in the scheme of the orthogonal accelerator allows nearly two-fold increase of the device resolution.

*Saint-Petersburg State Polytechnical University **Institute for Analytical Instrumentation RAS, Saint-Petersburg

The method of reception of identical resolving ability ∆М = const in an analytical quadrupole mass spec-trometer in a range of masses 2–500 u is described. It is achieved by the maintenance of strictly certain law of change of precision voltages relation changes — constant component U to the amplitude of a variable V voltage component φ = ± (U + V cos ωt), applied to the quadrupole analyzer electrodes. The method of precise U/V rela-tion measurement with the resultant curve which can be reproduced with high accuracy that maintains target electronic parameters of the HF-generator strictly constant and at the qualitative analyzer maintains ∆М = = const is suggested.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

A. N. Baltiysky, N. V. Krasnov, Characteristics of the small-sized precision high-speed high-frequency generator of analytical quadrupole mass analyzer are presented. The necessary parameters of the quadrupole analyzer, and accordingly generator parametres are defined, considering modern requirements presented to quadrupole mass analyzers, making a part of various mass spectrometer devices and complexes and realizing high-speed techniques of the analysis. Such parameters include long-term accuracy of mass maintenance within the ranges of 0.1 а.u.; hopping from one top of a peak to another during not more than 20 ms with accuracy of hitting the top of a peak not worse than ±0.1 a.u. and prolonged work at the top of the peak with this accuracy not less than 8 hours. Quadrupole mass-analyzer can work in two modes: RF — with a wide mass window and transition during 1 s to the mode DC/RF — divisions of ions in relation of mass to a charge.A. F. Kuzmin, S. B. Turtia

Institute for Analytical Instrumentation RAS, Saint-Petersburg

Algorithms to find peptides in protein databases for partially interpreted mass spectra of peptides have been developed. It has been shown that the use of mass index peptides allows users to search for online time a single sample, while the use of nondeterministic finite automata allows users to search a large number of samples dur-ing the reading of the database. For the first time algorithm tolerant to errors caused by replacing one amino acid by another or by one final mass by another was developed.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

A way to eliminate defocusing of charged particle beams in the dispersion plane in fringing fields of a sector deflector is proposed. The method is based on forming, by modification of the geometry of the deflector fring-ing field region, a non-monotonic distribution of the deflecting electrostatic field strength at the optic axis.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

The dynamics of growth of a gas bubble caused by stationary and oriented towards the surface of the bubble diffusional flux of molecules of the dissolved gas from the strongly supersaturated solution around the bubble is described analytically. The obtained dependence of the radius of the bubble on time since its nucleation ac-counts accurately for Laplace forces; and three stages, different from a physical viewpoint, are traced within this dependence. Characteristic bubble sizes that stipulate the boundaries of each of the stages and times correspond-ing to these stages are found. For each of the stages limitations on gas solubility necessary for stationary bubble growth are provided.

*Saint-Petersburg State University, Research Institute of Physics **Institute for Analytical Instrumentation RAS, Saint-Petersburg

The method for network designing with symmetrical neurons transformation functions (SNTF) based on higher-order statistics (HOS) was analyzed. This network was shown to provide noise lowering for un-stationary signal. In the information-measurement systems noises with Gauss distribution and noises with non-Gauss but symmetric distribution are well suppressed. The structure of the network based on HOS is shown, and is compared with the network structure (having SNTF) and common learning LMS algorithm.

Saint-Petersburg