A novel thin layer chromatography-flame ionization detection method for saturated, asphaltenes, resins, and asphaltenes group-type composition analysis with reverse order of chromatogram development.

The methodologies of asphaltenes-containing petroleum materials: saturated, aromatics, resins, asphaltenes group-type composition analysis are performed with the use of column adsorption-desorption or thin layer chromatography (TLC)-flame ionization detection under normal phase conditions with silica gel as the adsorbent. In a three-step procedure, the TLC chromatogram is developed within a decreasing distance by the mobile phase with increasing elution strength (polarity). The n-alkane used in the first step does not dissolve asphaltenes, which leads to the occlusion effect and an underestimation of the percentage of saturated hydrocarbons.

Separation and determination of the group-type composition of modern base and lubricating oils with a wide range of polarity, especially emitted to the environment.

Lubricating oils are composed of base oils (>85% v/v) and enriching additives (<15% v/v). Three types of base oils may be distinguished: 1) traditional bases (obtained by low-volatile fractions from crude oil distillation refining), 2) synthetic bases (mainly poly-alpha-olefins, sometimes esters, especially succinic acid esters), 3) bases of natural origin (especially obtained from refined plant oils). The bases of natural origin are the only ones recommended for application when lubricating oil may be emitted to the environment (e.

Ecological and Health Effects of Lubricant Oils Emitted into the Environment.

Lubricating oils used in machines with an open cutting system, such as a saw or harvester, are applied in forest areas, gardening, in the household, and in urban greenery. During the operation of the device with an open cutting system, the lubricating oil is emitted into the environment. Therefore, the use of an oil base and refining additives of petroleum origin in the content of lubricants is associated with a negative impact on health and the environment.

Hydrogen Production from Energy Poplar Preceded by MEA Pre-Treatment and Enzymatic Hydrolysis.

The need to pre-treat lignocellulosic biomass prior to dark fermentation results primarily from the composition of lignocellulose because lignin hinders the processing of hard wood towards useful products. Hence, in this work a two-step approach for the pre-treatment of energy poplar, including alkaline pre-treatment and enzymatic saccharification followed by fermentation has been studied. Monoethanolamine (MEA) was used as the alkaline catalyst and diatomite immobilized bed enzymes were used during saccharification.

Pretreatment of Lignocellulosic Materials as Substrates for Fermentation Processes.

Lignocellulosic biomass is an abundant and renewable resource that potentially contains large amounts of energy. It is an interesting alternative for fossil fuels, allowing the production of biofuels and other organic compounds. In this paper, a review devoted to the processing of lignocellulosic materials as substrates for fermentation processes is presented.

Chromatographic separation, determination and identification of ecdysteroids: Focus on Maral root (Rhaponticum carthamoides, Leuzea carthamoides).

The review presents general principles for choosing optimal conditions for ecdysteroid separation, identification, and isolation using HPLC/TLC techniques in RP, NP-HILIC or NP modes. Analytics of ecdyteroids pose a still insufficiently resolved problem. Plant-derived ecdysteroids are a point of interest of pharmaceutical industry and sport medicine due to their postulated adaptogenic and anabolic properties.

The Thin-Layer Microchromatography (μTLC) and TLC-FID Technique as a New Methodology in the Study of Lubricating Oils.

This paper concerns the possibility of using TLC coupled with a flame ionization detector (FID) and micro-TLC (μTLC) as precursors for microfluidized devices of analytical techniques to identify and determine the presence and content of the petroleum/vegetable oil base in the lubricating oils applied in cutting devices (chainsaws). This research is related to the problem of ensuring, in compliance with the requirements of environmental protection, a sufficient level of biodegradability of lubricating oils emitted to the environment during operation of equipment lubricated with these oils. Such oils include those mainly used in cutting devices and emitted in the form of a mist into the environment during the operation of those devices.

Novel stationary phases based on asphaltenes for gas chromatography.

We present the results of investigations on the possibility of the application of the asphaltene fraction isolated from the oxidized residue from vacuum distillation of crude oil as a stationary phase for gas chromatography. The results of the investigation revealed that the asphaltene stationary phases can find use for the separation of a wide range of volatile organic compounds. The experimental values of Rohrschneider/McReynolds constants characterize the asphaltenes as stationary phases of medium polarity and selectivity similar to commercially available phases based on alkyl phthalates.

Studies of the separation performance of silanized silica gel for simulated distillation.

We present the results of investigations of the chromatographic (sorptive) properties of silanized silica gel as a stationary phase for gas chromatography used for simulated distillation. Commercially available silanized sorbent (particle diameter range 63-200 μm, average pore size 60 Å) was sieved to obtain the 80-100 mesh fraction (180-150 μm). The obtained results revealed that silanized silica gel allows the complete separation of a mixture of n- and iso-alkanes in the C1 -C7 range.

Size-exclusion chromatography for the determination of the boiling point distribution of high-boiling petroleum fractions.

The paper describes a new procedure for the determination of boiling point distribution of high-boiling petroleum fractions using size-exclusion chromatography with refractive index detection. Thus far, the determination of boiling range distribution by chromatography has been accomplished using simulated distillation with gas chromatography with flame ionization detection. This study revealed that in spite of substantial differences in the separation mechanism and the detection mode, the size-exclusion chromatography technique yields similar results for the determination of boiling point distribution compared with simulated distillation and novel empty column gas chromatography.

Characteristics of volatile organic compounds emission profiles from hot road bitumens.

A procedure for the investigation and comparison of volatile organic compounds (VOCs) emission profiles to the atmosphere from road bitumens with various degrees of oxidation is proposed. The procedure makes use of headspace analysis and gas chromatography with universal as well as selective detection, including gas chromatography-mass spectrometry (GC-MS). The studies revealed that so-called vacuum residue, which is the main component of the charge, contains variable VOC concentrations, from trace to relatively high ones, depending on the extent of thermal cracking in the boiler of the vacuum distillation column.

Research on the separation properties of empty-column gas chromatography (EC-GC) and conditions for simulated distillation (SIMDIS).

Previous studies have revealed it is possible to separate a high-boiling mixture by gas chromatography in empty fused-silica capillary tubing rather than in columns coated with stationary phase. Chromatographic separation occurs solely on the basis of the different boiling points of the substances separated. The high similarity of such separations to those in classic distillation seems advantageous when gas chromatography is used for simulated distillation.

Application of normal-phase high-performance liquid chromatography followed by gas chromatography for analytics of diesel fuel additives.

The paper presents the results of investigations on new procedures of determination of selected cleaning additives in diesel fuel. Two procedures: one-step analysis using gas chromatography with flame ionization detection (GC-FID) or mass spectrometry (GC-MS) and a two-step procedure in which normal-phase high-performance liquid chromatography (NP-HPLC) was used for preliminary separation of the additives, were compared. The additive fraction was collected using either simple elution or eluent backflush.

T cell activation is driven by an ADP-dependent glucokinase linking enhanced glycolysis with mitochondrial reactive oxygen species generation.

Mitochondria-originating reactive oxygen species (ROS) control T cell receptor (TCR)-induced gene expression. Here, we show that TCR-triggered activation of ADP-dependent glucokinase (ADPGK), an alternative, glycolytic enzyme typical for Archaea, mediates generation of the oxidative signal. We also show that ADPGK is localized in the endoplasmic reticulum and suggest that its active site protrudes toward the cytosol.

Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen.

This paper describes a novel method of sample preparation for the determination of trace concentrations of polycyclic aromatic hydrocarbons (PAHs) in high-boiling petroleum products. Limits of quantitation of the investigated PAHs in materials of this type range from tens of nanograms per kilogram to <20 μg/kg. The studies revealed that in order to separate most of interferences from the analytes without a significant loss of PAHs, it is necessary to use size exclusion chromatography as the first step of sample preparation, followed by adsorption using normal-phase liquid chromatography.

A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions.

The distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures is often investigated by simulated distillation (SIMDIS) using capillary gas chromatography (CGC) with a short capillary column with polydimethylsiloxane as the stationary phase.

Application of high-performance liquid chromatography with ultraviolet diode array detection and refractive index detection to the determination of class composition and to the analysis of gasoline.

A method of effective application of normal-phase high-performance liquid chromatography (NP-HPLC) with ultraviolet diode array detection (DAD) and refractive index detection (RID) for the determination of class composition of gasoline and its components, i.e. for the determination of content of alkenes, aromatic and saturated hydrocarbons in gasoline meeting modern quality standards, has been developed.

Optimized conditions for hydrocarbon group type analysis of base oils by thin-layer chromatography-flame ionisation detection.

The results of research on the optimization of the thin-layer chromatography-flame ionisation detection for the determination of group composition of natural base oils, including separation of the aromatics into subgroups, are presented. Neutral base oils obtained in several steps of refining from vacuum distillation petroleum fractions are the most difficult to analyze by hydrocarbon group type analysis (HGTA) because of the high content of aliphatic fragments in their molecules. Factors affecting the accuracy and precision of the results were identified.

Determination of carbon monoxide, methane and carbon dioxide in refinery hydrogen gases and air by gas chromatography.

This paper illustrates a method for determining trace amounts of CO, CH4 and CO2 with the detection limit of 0.15, 0.15 and 0.

Determination of the amount of wash amines and ammonium ion in desulfurization products of process gases and results of related studies.

This paper describes a method for the determination of the so-called wash amines and their degradation products, including ammonium ions, in process liquids and wastewater generated during the desulfurization of hydrogen sulfide gas in the process of crude oil refining and also reports the results of related studies. Ion-exchange liquid chromatography employing an inexpensive cation-exchange HPLC column and refractometric detection was used. The results obtained were compared with those obtained by potentiometric titration.