Jelena Gorbatsova

• Ph D
• Researcher at Tallinn University of Technology

A compact, inexpensive sampler instrument for portable capillary electrophoresis (CE) was developed and tested to monitor common inorganic ions in drinking water samples. The sampler uses peristaltic and vacuum pumps and pinch and check valves to control liquid flows. The paper also addresses various aspects of CE associated with portability, open...

A compact, inexpensive sampler instrument for portable capillary electrophoresis was developed for monitoring illegal drugs in human body fluids and evaluated for γ-hydroxybutyric acid (GHB) in simulated saliva samples. The sampler uses peristaltic pumps and pinch and check valves to activate liquid flows. This short communication addresses aspects...

The aim of this study was to investigate the influence of organic solvents on the electrophoretic separation of phenylethylamines. The background electrolyte composition was adjusted with different protic (methanol, ethanol, and 2-propanol) and aprotic (dimethyl sulfoxide and acetonitrile) solvents. Two groups of analytes were studied. The first gr...

Currently used methods for in-field determination of illegal drugs involve various test kits based mainly on the immunoassay technique, where the presence of a compound of interest is assessed by antibody-antigen reaction and manifested by observable color change. Despite being accepted and widely used by police forces to test the presence of illeg...

Flow analysis is the science of performing quantitative analytical chemistry in flowing streams. Because of its efficiency and speed of analysis, capillary electrophoresis (CE) is a prospective method for the monitoring of a flow composition withdrawn from various processes (e.g., occurring in bioreactors, fermentations, enzymatic assays, and micro...

A proof of the principle of a gas chromatograph (GC) assembled using consumer products and operating with ambient air as a carrier gas and a gas sensor as a detector is described. Due to the wide availability of parts, as well as low cost (about one hundred Euros) this chromatograph serves as an example of a simple and portable instrument, which co...

The development of the instrument which will significantly ease the in situ samplings of volatile compounds is described. The purpose of this work was to design an automated, portable, handheld sample collection device that operates with monolithic adsorbents. The sampler contains two lithium-ion batteries, collects samples into micro-liter range v...

Hazardous remote places exist in the world. Why should health or life be risked sending a scientist to the investigation site, as the remote analytical instrumentation exists? Different scientific fields require instruments that could be used on-site (in situ), therefore the purpose of this work was to design a fully automated chemical analysis sys...

Capillary electrophoresis often causes unrepeatable peak migration times in the electropherogram due to changes of electroosmosis, yet in some cases this separation technique does not have a replacement alternative. Some attempts to overcome this issue have been performed introducing internal standards into the sample and compensating peak shifting...

The objective of this Short Term Scientific Mission was to test the suitability of capillary electrophoresis for determination of rain water chemical composition. The fully functional, open-hardware, low-cost instrument was assembled and tested. An original protocol for determination of the chemical content of rain water was established and validat...

Portable and autonomous analytical instrumentation is becoming more important. Portable instrumentation can be designed via the miniaturization approach and this is a challenging task due to: (i) the limited battery power supply, (ii) a low number of mechanical and moving parts allowed in the design and (iii) susceptibility to changing environment...

One of the main problems of the remote complex sample analysis instrumentation is that such systems are susceptible to temperature fluctuations. Temperature regulation is energetically ineffective, and it is not used in most of the field portable analytical systems. Separations performed in a changing temperature environment provide electropherogra...

In the present work we demonstrate the novel approach to improve the sensitivity of the “out of lab” portable capillary electrophoretic measurements. Nowadays, many enhancement methods are: (i) underused (non-optimal), (ii) overused (distorts the data), or (iii) inapplicable in field-portable instrumentation due to lack of computational power. Desc...

The axial C4D (Capacitively Coupled Contactless Conductivity Detection) measurement electronics for capillary electrophoresis is considered and a new improved C5D compensated detection concept is proposed and tested. Using the idle compensation channel with inversed signal and immediate analogue summation of the active and idle channel currents yie...

In this work, the concept of a field-portable analyzer is proposed that operates with milliliter amounts of solvents and samples. The need to develop such an analyzer is not only driven by specific extraterrestrial analysis but also, for example, by forensics applications where the amount of liquid that can be taken to the field is severely limited...

An automated fraction collection interface was developed for coupling CE with MALDI-MS. This fraction collection approach is based on the electrowetting on dielectric (EWOD) phenomenon performed on a digital microfluidic (DMF) board; it does not rely on a MALDI spotter. In this study, a four-peptide mixture was used as a sample test, and the separa...

Present article describes a novel technique based on digital microfluidics that allows collecting fractions of interest after electrophoretic separation and detection for further ESI-MS investigation. In this technique, a mixture is injected into a capillary electrophoresis (CE) apparatus, and microliter droplets are generated at the CE outlet at a...

The capillary electrophoretic separation of six water-soluble vitamins (thiamine, nicotinic acid, nicotinamide, d-pantothenic acid, pyridoxine and ascorbic acid) was studied. Four CE backgrounds electrolytes were optimized and the most suitable ones were applied for investigation of analytes in real samples (yeast, beer, syrups). Several extraction...

A new sample introduction/analysis approach was developed by combining a digital microfluidic (DMF) device with a portable capillary electrophoresis (CE) analyzer based on short separation capillary and contactless conductivity detection. The DMF sample injection was performed by transporting sample and buffer droplets in succession under the CE ca...

Because of their antioxidative capability polyphenols and vitamins are the most important naturally occurring compounds. Several widely consumed vegetables are rich in various phenolic compounds and vitamins. In this study, such vegetables as tomato (Solanum lyco-persicum), eggplant (Solanum melongena), chilli pepper (Capsicum annuum), and potato (...

The increased interest in sea buckthorn (Hippophae rhamnoides L.) made it possible to investigate the antioxidant content in it. To address this issue, the presence of following antioxidant compounds were analyzed: trans-resveratrol, catechin, myricetin, quercetin, p-coumaric acid, caffeic acid, L-ascorbic acid (AA), and gallic acid (linear range o...

N,N'-Alkylmethylimidazolium cations have been separated in NACE when one of the N,N'-dialkylimidazolium salts (ionic liquids (ILs)) was used as an electrolyte additive to the organic solvent separation medium. The separated species were 1-methyl-, 1-ethyl-, 1-butyl-, 1-octyl-, 1-decyl-3-methylimidazolium and N-butyl-3-methylpyridinium cations and B...