7^th International Conference and Exhibition on Analytical & Bioanalytical Techniques September 28-30, 2016 Orlando, Florida, USA

Biography:

Shobini Jayaraman has completed her PhD from Indian Institute of Technology, Madras, India and postdoctoral studies from Weizmann Institute of Science, Israel. She was the recipient of Sir Charles Clore fellowship at Weizmann Institute of Science. Currently she is a senior research scientist at Boston University School of Medicine. She serves as the liaison for academic and industrial contract research services at Boston University. She has published more than 25 papers in reputed journals. Here recent publication in JBC has been chosen as Paper of the month in May-2014 by International Atherosclerosis Society.

Abstract:

Lipoproteins are nanoparticles comprised of proteins and lipids that provide vehicles for transport of fat and cholesterol in circulation. High levels of certain lipoproteins increase the risk of heart disease. Each lipoprotein is a non-covalent assembly of several proteins and several hundred lipids. The major challenge in the biophysical analysis of lipoproteins arises from their heterogeneity in size (7-100 nm), density (1.06-1.22 g/L), and protein and lipid composition. Moreover, lipoproteins are highly dynamic assemblies undergoing continuous remodeling via various enzymatic and non-enzymatic reactions. This provides a major challenge for detailed structural studies of lipoproteins. To overcome this challenge, we designed an integrated biophysical approach by combining far- and near-UV circular dichroism (CD) spectroscopy, turbidity, differential scanning calorimetry (DSC), fluorescence spectroscopy, transmission electron microscopy (EM), size-exclusion chromatography (SEC) and other methods to analyze the structure and remodeling of all major lipoprotein classes. This integrated approach was used to study thermal denaturation of human low- and high-density lipoproteins (LDL and HDL, or bad and good cholesterol). The results clearly showed that lipoprotein stability is controlled by kinetics barriers. Interestingly, heat-induced remodeling of all lipoproteins involves partial protein unfolding/dissociation and lipoprotein fusion and rupture. These structural transitions mimic key aspects of in-vivo lipoprotein remodeling. These and other emerging approaches will allow one to study structural, dynamic and functional properties of larger more challenging systems. Ultimately, such integrated approaches are hoped to bridge the gap between the biophysical studies of isolated macromolecules or their complexes, and the complexity of cellular systems.

Biography:

Eamonn completed his PhD at the age of 25 years from the University of Oxford working on membrane proteins within the laboratory of Prof. Dame Carol Robinson, where he held a collaboration with GSK on drug metabolite structure determination. He then performed a year’s postdoctoral study at King’s College London with Prof. Paula Booth before being awarded a BBSRC Future Leader Fellowship in 2016. His main focus is developing new analytical techniques and protocols for structural biology, particularly in the areas of membrane protein folding, function, and drug and lipid interactions.

Abstract:

Ion mobility-mass spectrometry (IM-MS) in combination with molecular modeling offers the potential for small molecule structural isomer identification by measurement of their gas phase collision cross sections (CCSs). Successful application of this approach to drug metabolite identification would facilitate resource reduction, including animal usage, and may benefit other areas of pharmaceutical structural characterization including impurity profiling and degradation chemistry. However, the conformational behavior of drug molecules and their metabolites in the gas phase is poorly understood. We investigated the gas phase conformational space of drug and drug-like molecules as well as the influence of protonation and adduct formation on the conformations of drug metabolite structural isomers. The use of CCSs, measured from IM-MS and molecular modeling information, for the structural identification of drug metabolites has also been critically assessed. Detection of structural isomers of drug metabolites using IM-MS is demonstrated and, in addition, a molecular modeling approach has been developed offering rapid conformational searching and energy assessment of candidate structures which agree with experimental CCSs. Here it is illustrated that isomers must possess markedly dissimilar CCS values for structural differentiation, the existence and extent of CCS differences being ionization state and molecule dependent. The results present that IM-MS and molecular modeling can inform on the identity of drug metabolites and highlight the limitations of this approach in differentiating structural isomers.

Biography:

Jie He is currently a 4^th year graduate student in the Sagle group at the University of Cincinnati.  Her thesis involves the devlopment of plasmonic on-chip devices for rapid, portable, colorimetric assays.  She has authored 4 peer-reviewed articles, in addition to a book chapter.

Abstract:

Localized Surface Plasmon Resonance shows excellent promise as next generation biosensing materials, since they provide sensitive, label-free, rapid, colorimetric detection that is amenable to on-chip devices.¹  We have recently incorporated uniform nanoparticle arrays into microfluidic and multiplexed devices through the combination of photolithography and colloidal lithography.²  This presentation will highlight two recent applications we have carried out using this technology.  The first application involves the fabrication of 96-well glass/PDMS plates that fit into commercially available UV-Vis plate readers.  With these plates, we have carried out drug screening aimed at disrupting the interaction between the Human Antigen R (HuR) protein and its RNA binding partner, which has recently been implicated in cardiac hypertrophy.³  In addition, these uniform nanoparticle arrays can be fabricated on other substrates including flexible polymers, which make the devices less expensive and more portable.  The second application discussed is a rapid, point-of-care assay for pathogenic species associated with sexually transmitted disease.  These assays involve portable, miniaturized spot plates in which small sample volumes can be used to test for pathogenic species in a multiplexed manner.  Combining our technology with color analyzing software available on the I-Phone enables rapid read-out in low resource settings. 

1. Unser, S., Bruzas, I., He, J., and Sagle, L., Sensors, Vol. 15, No. 7, 15684-15716, 2015.
2. He, J., Boegli, M., Bruzas, I., Lum, W., and Sagle, L., Analytical Chemistry, Vol. 87, No. 22, 11407-11414, 2015.

Kraynik, S., Anthony, S., and Tranter, M., The FASEB Journal, Vol. 29, No. 1, 982, 2015

Biography:

Jie Wang is working in DMPK Department at Sanofi Genzyme, USA

Abstract:

Serial sampling methods have been routinely used for rat pharmacokinetic (PK) studies . It is still common to take 100-250 µL of blood at each timepoint when performing a PK study in rats using serial sampling.  Recently, microsampling (< 50 µL) techniques have been reported as an alternative process for collecting blood samples from rats. In this report, three proprietary compounds and two marketed drugs, fluoxetine and glipizide, were dosed orally into rats. Whole blood (and plasma) and capillary microsampling (CMS) samples were collected from jugular vein cannula (JVC) and tail-vein from the same rats. For the three proprietary compounds, the blood AUC as well as the blood concentration-time profile obtained from the tail vein was different from that obtained via JVC sampling.  For fluoxetine, the blood AUC was not statistically different when comparing tail-vein sampling to JVC sampling, while the blood concentration-time profile that was obtained from the tail vein was different than the one obtained from JVC sampling. For both fluoxetine and glipizide, the blood concentration profiles obtained from CMS were equivalent to the blood concentration profiles obtained from the standard whole blood sampling, regardless of the sampling site.  Thus, it is recommended that a consistent blood sampling method should be used for serial microsampling in discovery rat PK when testing new chemical entities. If the rat tail-vein sampling method is selected for PK screening, a bridging study on the lead compound is recommended to confirm that PK from JVC sampling is comparable to the tail vein sampling.

Biography:

Dr. Rogatsky serves as the Editor-in-Chief for the Journal of Chromatography and Separation Techniques (OMICS publishing group). During the last 10 years (from 2005), Dr. Rogatsky has published over 30 scientific papers in per-reviewed journals (mostly as the first author) and has presented over 50 posters and lectures. Overall, he has made more than a hundred scientific presentations and publications. Dr. Rogatsky completed his M.Sc. in physical chemistry at Belarus State University (former USSR) in 1990. He completed his PhD in bioanalytical chemistry (Bar-Ilan University, Israel) in 1998. At the end of 1999, he started his post-doctorate at Albert Einstein College of Medicine and became a faculty member since 2001 and was a mass spectrometry director at the Biomarker Analytical Resource Core. His title was Associate Research Professor of Medicine. From October 2015 Dr. Rogatsky is a supervisor of the Chemical Threat Laboratory in the Division of Environmental Health Sciences at Wadsworth Center, Albany NY, USA.

Abstract:

Method transfer from conventional LC/MS to UHPLC/MS seems to be straightforward and simple. Reality however, may be different. Hardware design of LC, UPLC and mass spectrometer, method throughput  and assay ruggedness, - these factors may have a critical impact on method transfer. Certain case studies will be presented and critical aspects and typical issues of LC/MS to UHPLC/MS method transfer will be discussed.

Biography:

Tianyu Zheng received his BS in Chemistry from the Northwest University of China in 2014. He is currently a PhD candidate in Chemistry with Dr Qun Huo in the NanoScience Technology Center at University of Central Florida (UCF). His primary research interest is gold nanoparticles together with dynamic light scattering for protein detection, size analysis and structural study.

Abstract:

Dynamic light scattering (DLS) is an analytical technique used routinely to measure the hydrodynamic sizes of particles with diameters in the nanometer region. Gold nanoparticles are known for their exceptional light scattering properties. By combining the strong light scattering property of gold nanoparticle probes with the size measurement capability of DLS, a new technique named as D2Dx (from diameter to diagnostics) for chemical and biological target detection and analysis was developed. Gold nanoparticles can be surface-modified with various chemical ligands, antibodies or other binding molecules to form gold nanoparticle probes. The binding of chemical or biological target analytes with their specific gold nanoparticle probes can lead to nanoparticle cluster formation, and subsequently, an average particle size increase of the assay solution. Such particle size increases can be measured by DLS, and correlated to the quantity of the target analytes. D2Dx is a single-step homogeneous solution assay, easy to perform, of low cost, and has excellent sensitivity and reproducibility. So far, this technique has been applied successfully for quantitative detection and analysis of a wide range of chemical and biological targets, including proteins, DNAs, viruses, carbohydrates, small chemicals, toxic metal ions, food and environmental toxins. In this talk, I will explain the principle of D2Dx, give an overview on the application potentials of this technique in biomedical research, food safety and environmental protection, and then present several specific examples of using D2Dx for protein detection and analysis.

Biography:

Dan Jin completed her MSc and BSc at Peking University and is currently working towards a PhD under the supervision of Dr. Jie Chen at the University of Alberta. Her current research is a joint venture between the University of Alberta and Labs-Mart Inc., blending analytical chemistry, biochemistry, and biomedical engineering to develop practical solutions usable in industry.

Shengxi Jin holds a BSc in chemical engineering from the University of Alberta and a MBA from Queen’s University. He applies his academic knowledge and business experience to improve laboratory efficiency in industrial settings. Shengxi’s expertise includes LIMS development and computer process control.

Abstract:

Research on medicinal cannabis has been hampered by its legal status as a narcotic. However, the recent legalization in North America regarding the use of medicinal cannabis necessitates standardized phytochemical composition for commercial products in the interest of consumer safety and medicinal efficacy. The first step towards utilizing medicinal cannabis as a reliable mainstream medicine is cannabis cultivar distinction based on two main groups of medicinal ingredients: cannabinoids and terpenes. We have recently developed and validated GC-MS and HPLC-UV methods for quantifying dozens of phytochemicals characteristic to commercially-available cannabis strains. We are applying these analytical methods to profile cannabinoids and terpenes in cannabis strains and, together with PCR, to correlate chemotaxonomic and genetic information. The results will contribute to the establishment of an industrial standard for phytochemicals in commercially-available cultivars in support of a continuously-growing market.

Biography:

Ashraf Ali Khan has completed his PhD at the age of 28 years from Advanced separation science laboratory, Department of Chemistry and chemical engineering, Inha University South Korea and now he is postdoctoral fellow in the same laboratory. He is working on the preparation of silica based stationary phases (C8, C18, Mixed mode) for reversed phase high performance liquid chromatography (RP-HPLC). Preparation of highly efficient CEC and long LC columns for carbohydrate, peptide and protein analysis. Coupling of our developed long LC columns with mass spectrometry (LC/MS). He has published more than 10 papers in reputed journals.

Abstract:

Sub-2μm porous silica monolith particles have been prepared successfully prepared by sol-gelprocess followed by grinding and calcinations at 550ËšC. The particles were derivatized with a C18 ligand followed by end-capping with a mixture of hexamethyldisilazane (HMDS), andtrimethylchlorosilane (TMCS). The resultant phase was packed in glass lined stainless steel microcolumn is much better than that of commercial C-18 phase. This phase has shown some encouraging possibility for fast analysis when packed in a short column. This study offers a promising vision towards commercialization of chromatographic phases based on silica monolith particles.

Graphical abstract

Fig.1. Microscopic view of silica monolith particles (a) and SEM images of C18-bound silicamonolith particles with different magnification (b, c, d). The scale bars are 20, 10, and 1 μm forc, and d, respectively. 0 5 10 15 20 25 30 min

Fig.2. Chromatogram C18-bound sub-2μm silica monolith particles of current study. The mobilephase and column dimension is 60/40 acetonitrile/water, 0.1% TFA, 214nm and (1mm ID x 300m m length). The analytes elusion order is: Phenol, Acetophenone, 4-Methyl-2-nitroanailine, Benze ne and Toluene

Biography:

Dr Makhafola is currently the General Manager: Research & Development at Mintek. He worked as Lecturer in Analytical Chemistry at Technikon Northern Gauteng (now called Tshwane University of Technology) and University of Venda. In 2004 was appointed Director: Quality Assurance at Border Technikon (now called Walter Sisulu University). Dr Makhafola was the Director: Quality Assurance at the University of Venda until he joined University of Kwa-Zulu Natal as the Director Quality Promotion & Assurance in July 2010, part of his responsibility was to lead the World University Rankings project. 

Dr Makhafola served as member of Umalusi Council and also as Chairperson of Lovedale FET College Audit Committee. He is currently the Chairperson of DST/MINTEK Nanotechnology Innovation Centre Steering Committee. He served as a member of the Higher Education Quality Assurance Manager’s Forum and also chaired and facilitated various workshops on quality assurance in higher education. He is also serving as an academic committee member of QS World Ranking Universities. Dr Makhafola did the post-doctoral training in Analytical Chemistry at Indiana University. He presented his research work in more than 19 international conferences and published in credible journals.

Abstract:

Mintek provides world class research and development expertise, testwork, and process optimization for the mining industry locally and internationally. Mintek’s Cynoprobe online in-process cyanide analyzer for gold leaching operations continues to enjoy success, with close to 100 installations on sites across the globe. The use of the amperometric method helps limit interferences from unwanted species, makes the instrument cost effective to run, facilitates rapid measurement cycles, and enables the measurement of both Free and Weak Acid Dissociable (WAD) cyanide in one instrument. One of the notable outputs from Mintek’s 2015 research is a prototype hand-held version of Mintek’s Laboratory “Lab” Cynoprobe. The Lab Cynoprobe was developed several years ago to broaden the impact of Mintek’s cyanide measurement technology, and facilitates the use and evaluation of this amperometric technique within a Client’s own laboratory to assist with International Cyanide Management Code (ICMC) compliance and to evaluate the measurement principle for wider online implementation of the Cynoprobe v3 as part of a broader ICMC compliance strategy. Mintek has sold over 15 of these units in recent years, and has seen increased requests from industry for the instrument. The present version of the Lab Cynoprobe unit is ultimately a simplified version of the Cynoprobe 3 instrument. The drawback of the existing Lab Cynoprobe unit is the high cost associated with manufacturing the instrument. As a consequence, a project was initiated to develop a portable Handheld Cynoprobe unit using embedded technology to replace the expensive Lab Cynoprobe. In 2015 a hand-held, battery operated prototype of the unit was tested and shown to produce excellent results. A cost comparison was performed and indicates an expected manufacturing cost reduction of greater than 70% between the old Lab Cynoprobe and new Handheld Cynoprobe.

Biography:

Peter J Baugh is currently the Environmental and Food Analysis Special Interest Group Leader for The British Mass Spectrometry Society.  He has published over 70 papers in a variety of  radiation and environmental fields and in respected journals.

Abstract:

The hazardous constituents of cigarette smoke have attracted considerable attention lately, especially with increasing regulation around the world limiting or banning smoking in public places – and even in private cars if children are present.

From an analytical perspective, however, there is much that remains to be learnt about the composition of cigarette smoke, because of its high degree of complexity – tobacco smoke is thought to contain thousands of components across multiple chemical classes and wide concentration ranges.

Comprehensive two-dimensional gas chromatography (GC×GC), when coupled with time-of-flight mass spectrometry (TOF MS), has been shown to provide improved chemical fingerprinting of complex samples in areas of study as diverse as petrochemical analysis and fragrance profiling.  However, commonly-used thermal modulation devices are unable to successfully modulate the most volatile components.

 In this study, we use thermal desorption (TD) for collection and analysis of whole cigarette emissions, and couple it with flow-modulated GC×GC–TOF MS, to enable the constituents of whole smoke to be routinely and confidently sampled, separated and identified.

The use of novel Tandem Ionisation™ is also harnessed to increase the analytical resolution of the system, by providing both reference-quality 70 eV spectra and soft electron ionisation (EI) spectra simultaneously in a single analysis. The complementary soft EI spectra provide a powerful means of identifying compounds that exhibit similar mass spectral characteristics (or extreme fragmentation) at conventional 70 eV energies, but without the inconvenience typically associated with conventional soft ionisation techniques.

Biography:

Song Gao, Ph.D., is currently an Associate Professor of Chemistry at Stetson University in Florida, USA. He received his Ph.D. in Chemistry from the University of Washington and did his postdoctoral training on Atmospheric Chemistry at California Institute of Technology (Caltech).  He has received

Abstract:

The detailed chemical composition of atmospheric aerosols plays a key role in understanding their impact on the climate system, yet this information is still poorly understood due to the complicated molecular identity and transformation pathways involved.  In addition, aerosol chemistry involved in urban smog pollution also requires detailed analytical characterization.  This talk discusses how some analytical techniques can yield insights on aerosol chemical composition.  In the laboratory, reactions among carbonyls and amines, common pollutants in urban areas, were carried out to verify the validity of the Mannich reaction in the urban atmosphere. Gas Chromatography-Mass Spectrometry analyses indicate that Mannich-type products form under common acidity and temperature conditions, consistent with ambient observations and proposed mechanisms.  In a separate case involving long-range transport, size-resolved aerosol samples were collected in the Caribbeans. Meteorological and chemical analyses, utilizing atomic absorption, show that these aerosols frequently had their origins in African desert, and carried mineral elements to enrich the soil in the Caribbeans.  In addition, dust and black carbon were distributed in coarse and fine aerosol particles, respectively, due to their different sources and evolution pathways.  Novel analytical techniques are needed to further unravel the unknown species in atmospheric aerosols and their roles in climate and pollution studies.

Biography:

Prof. Chenzhong Li, is the director of the Nanobioengineering/Bioelectronics laboratory at Florida International University. The impact of his work is documented in 9 granted patents and more than 100 peer-reviewed journal papers and over 140 presentations at National/International conferences including more than 90 keynote/invited lectures and seminars. He is the associate editor of 3 SCI indexed scientific journals and received numerous awards and honors such as Kaufmann Professor Awards.

Abstract:

Understanding and controlling the interface between neuronal cells and neuronal network and electrical devices is vital to both biological science and technology. Recent developments in the field of in vitro neuron mapping focus on the development of optical and electrochemical strategies for either single neuron cell/neuron measurement or artificial neuronal networks/brain slices mapping. To mimic in vivo neuronal networks and to elucidate the mechanisms of computation, spontaneous and elicited electrical activity need to be monitored, and multiple simultaneous recordings are required for monitoring individual unit and collective network activity. In this way, both individual cells and cell networks can be scrutinized in order to understand how changes in single unit activity and functionality. In the present study, we developed a large-scale integration -based amperometric sensor array system for electrochemical bioimaging and throughput sensing of dopamine expression from three-dimensional (3D)-cultured PC12 cells upon dopaminergic drugs exposure. It has been shown that individual cells behave differently from the population even under the identical conditions, as a complementary study, we also explore the possibility of single cell-on-chip based analytical technique which can collect real-time change in cell physiology by measurement of cell exocytosis, i.e., release of neurotransmitters, in a neuronal model cell line, i.e. PC12 cells. The study of single cell dynamics could help us better understand the complex processes, such as, neurotransmitter kinetics, ion channel functions, and cell communications, single cell analysis can be an equivalent and complementary strategy to existing approaches.

Biography:

Dr. Zahir Akhunzada a PPD Consultant in the Analytical & Bioanalytical Development department at Bristol-Myers Squibb in New Brunswick, New Jersey where he is responsible for the analysis and characterization of proteins by MFI and related techniques. Before joining PPD, he worked for Schering-Plough/Merck. He was Assistant Prof. at King Saud University Riyadh Saudi Arabia and a Guest Investigator at the VA Hospital in Newark, NJ. He has a broad range of expertise in R&D, spectroscopy, chromatography, wet analytical techniques and biologics. He acquired research experience in the Netherland, Pakistan and earned his Ph. D. in Chemistry in 1992. He did his Post doctorate in Germany, has several research publications and co-Authored , a textbook with Prof. Atta-ur-Rahman on ”Stereoselective Synthesis in Organic Chemistry”, published (1993) by Springer Verlag, New York.

Abstract:

Waste Plastic is huge problem in USA and around the Global. This is global problem . Inventions of the twentieth century, plastics are everywhere. Society has found ample ways to use plastics. But users are less adept at managing the material when they are finished with it—often after only one use. The volume of plastics being produced, used, generated, and discarded is greater than ever before. Plastics therefore require increasing effort and ingenuity to properly manage. Annually, of the 120 billion pounds of plastics produced in the United States only about 6% or 4.8 billion pounds are recycled. For all the talk of plastic bans, plastic production is increasing. Waste Technologies LLC (WTL) has the solution at its disposal. This technology can produce approximately 1.3 liter of “WTL fuel” from one kilogram of plastic waste. The exact yield depends on the type of plastic, and the grade of WTL fuel desired. Typically, the process produces a residue of less than 5% of the weight of the plastic waste. This residue is rich in carbon and may be an environmentally superior substitute for coal with a higher BTU value. The WTL technology is able to cater to a wide range of diverse applications, including but not limited to fuel, gas and electrical generation. NSR’s / WTL patented technology, in conjunction with WTL technology and know-how, is a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbons of liquid fuel. WTL believes that it can convert approximately one tonne of plastic into about 300 gallons of fuel at a cost of about $0.75-$1.00 per gallon and produces 4,205 ft3 (CFT) of light gas (C1-C4) byproduct when developed to commercial size. WTL’s refining process is uncomplicated and promises to be very competitive with large crude oil installations. In financial projections WTL uses $30/bbl. ($0.71 per gallon) for preprocessing and refining costs. Other plastic recycling technologies generally have a very narrow band of plastics they can use. Nearly all recycling is done with plastic designations 1 or 2 while designations 3 through 7 are virtually untapped (over 70% of all plastic fall within these categories). A combination of economic and technological factors account for this situation. The advantage of WTL technology is that it can produce a profitable product from material that society generally pays to thrown away. It is this no or low cost feedstock that is the key advantage.

Biography:

Dr. Zahir Akhunzada a PPD Consultant in the Analytical & Bioanalytical Development department at Bristol-Myers Squibb in New Brunswick, New Jersey where he is responsible for the analysis and characterization of proteins by MFI and related techniques. Before joining PPD, he worked for Schering-Plough/Merck. He was Assistant Prof. at King Saud University Riyadh Saudi Arabia and a Guest Investigator at the VA Hospital in Newark, NJ. He has a broad range of expertise in R&D, spectroscopy, chromatography, wet analytical techniques and biologics. He acquired research experience in the Netherland, Pakistan and earned his Ph. D. in Chemistry in 1992. He did his Post doctorate in Germany, has several research publications and co-Authored , a textbook with Prof. Atta-ur-Rahman on ”Stereoselective Synthesis in Organic Chemistry”, published (1993) by Springer Verlag, New York.

Abstract:

The presence of sub-visible particles (SVPs) is a major challenge in the development of therapeutic protein formulations. Distinction between proteinaceous and non-proteinaceous SVPs is vital in monitoring the formulation stability. The current compendial method based on light obscuration (LO) has limitations in analyzing translucent particles, requires large analysis volume and therefore demands urgent need for an unambiguous method to characterize SVPs. A number of attempts have been made to characterize SVPs, albeit with limited success. This presentation reveals a method that successfully characterizes and distinguishes, both potentially proteinaceous and non-proteinaceous SVPs in protein formulations by using Microflow Imaging (MFI) in conjunction with the MVAS (MFI View Analysis Suite) software.

Biography:

Mr. Miroslav Ryska (1938) holds an undergraduate degree from Charles University, along with an M.S. in Physical Chemistry from Moscow State University and a PhD. from the Institute of Macromolecular Chemistry of Czechoslovak Academy of Sciences. From 1961 to 1978 he worked at the Institute of Macromolecular Chemistry of the Czechoslovak Academy of Sciences. In 1978 - 1997 he worked as a researcher in the field of MS and its application in research of metabolism and pharmacokinetics of drugs at the Research Institute for Pharmacy and Biochemistry in Prague. He has written more than 100 publications mainly on the topic of mass spectrometry, trace analyses, analyses of drugs, metabolites and quantitative analysis. In the 1990’s Mr. Ryska acted as an Editor of two international journals, The Journal of Mass Spectrometry and Rapid Communication in Mass Spectrometry. He founded Quinta-Analytica s.r.o.in 1997 and currently holds the position of Vice President.

Abstract:

The source of the Matrix effect as a consequence of analyte ions suppression or ions enhancement must be sought in the presence of unknown impurities from matrix. These impurities can be regarded as Brønsted bases or acids. They are participating in the complex ionization process in parallel or competing ion-molecular reactions. Not only impurities from extracts but impurities adsorbed in the ion source and/or in the analytical system may play an important role in the extensively understood term “Matrix effects“. These adsorbed substances cannot be fully removed from the system by any cleaning procedure. On the other hand, this effect may be effectively used in the sensitive method of the determination of some drugs (e.g. lacidipine). To fully compensate for the negative impact of the “Matrix effect“, use of isotopically labeled internal standards (isotope dilution technique) proved to be the only effective technique. This applies especially to LC/MS/MS determination of drugs and their metabolites in complex extracts of biological matrices. The isotope dilution technique is successful regardless of the method of purification, the ionization technique (APCI or ESI in both positive and negative ion modes), and the type of the equipment used. In addition, the quality of isotopically labeled internal standards (with respect to the kinetic isotope effects dependent on the number of deuterium atoms present) is not crucial either. The isotope dilution technique proved to be 100% effective for the compensation of matrix effect influences in more than 100 analytical methods developed and validated. The strict requirements of EMEA guidelines to investigate different plasma sources for the assessment of the matrix effect in the analytical method validation are discussed further within this context.