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.g. when the machine with an open cutting system is used). Group-type separation and analysis of group-type composition of base and lubricating oils are of significant importance in quality control and environmental monitoring. Due to the potentially wide range of polarity of the components of base and lubricating oils, group- type separation becomes a difficult separation problem. It is also a serious analytical problem due to the considerable diversity of physicochemical properties. The authors propose a new procedure for the separation and determination of the group-type composition of base and lubricating oils using thin-layer liquid chromatography in normal phase systems (abr. NP-TLC) on silica gel plates impregnated with berberine salt/in the coupling of thin-layer chromatography with flame ionization detection (abr. TLC-FID). A new, effective procedure of TLC plates impregnation with berberine sulphate was presented. The proposed procedure ensures the visualization of all groups of base oils. Extensive experimental research showed that a 2-step development procedure with application of n-hexane up to 100% height of development +15 min and further n-hexane: isopropanol: tri-fluoroacetic acid 96.25: 3: 0.75 (v: v: v) up to 75% height of development is advantageous for the group-type separation, both in TLC-FID and TLC.

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. In insects, ecdysteroids regulate larval transformation. Maral root (Rhaponticum carthamoides, Leuzea carthamoides), traditional Siberian folk-medicine plant used as stimulant to boost overall health and fitness, is a particularly rich source of a wide variety of phytoecdysteroids. The similarity of molecular structures of ecdysteroids present in its extracts together with high content of unrelated compounds of similar chromatographic characteristics makes optimization of separation, identification and isolation of ecdysteroids a difficult analytical task. In that respect, two-dimensional separations, two-dimensional separations, 2D HPLC or 2D TLC, could be of use. For identification, the hyphenated techniques are particularly important. Thus, comprehensive overview of MS spectral parameters of ecdysteroids is provided. Described principles could easily be applied for separation of ecdysteroids in extracts from other sources. They are also useful for development of separation procedures for isolation of ecysteroids in preparative-scale applications.

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. When oil components are eco-toxic, contamination of the environment occurs. New methodologies for the identification and determination of the petroleum oil base, which is very difficult to biodegrade, as well as the easily biodegradable ingredients of vegetable origin in the lubricating oils, are presented. The described procedures indicate in an indisputable way whether the oil contains the oil base originating from crude oil and whether it contains adequate enriching additives. The procedures also allow the assessment of the content of particular groups of constituents (µTLC) or the determination of the group composition (TLC-FID).