Characterization of crude oil and its saturate, aromatic and resin fractions by high-field asymmetric waveform ion mobility spectrometry – high resolution mass spectrometry

High-field asymmetric waveform ion mobility spectrometry (FAIMS) was coupled to a high-resolution Orbitrap mass spectrometer (MS) with a heated electrospray ionization (HESI) source for the analysis of crude oil and respective saturate, aromatic, and resin fractions. Four classes of compounds N1, N1S1, O1S1, and O2S1 were investigated using FAIMS one-dimensional compensation field scans from −3 to 5 Td for the crude oil and FAIMS static scans from 0.5 to 2.5 Td with 0.5 Td increments for fractions. In all cases, the incorporation of FAIMS into the analysis resulted in an increased number of detected peaks for both the crude oil and fractions. The most significant change was noticed in the aromatic fraction, with an increase of 218% for N1 and up to 514% for the O2S1 class of compounds observed. In addition, pre-analytical fractionation combined with FAIMS–MS enabled a higher number of molecular features to be observed in comparison to whole oil for three classes of compounds N1, O1S1, and O2S1 by 19, 45, and 83%, respectively

The quantitative surface analysis of an antioxidant additive in a lubricant oil matrix by desorption electrospray ionization mass spectrometry

Rationale Chemical additives are incorporated into commercial lubricant oils to modify the physical and chemical properties of the lubricant. The quantitative analysis of additives in oil-based lubricants deposited on a surface without extraction of the sample from the surface presents a challenge. The potential of desorption electrospray ionization mass spectrometry (DESI-MS) for the quantitative surface analysis of an oil additive in a complex oil lubricant matrix without sample extraction has been evaluated. Methods The quantitative surface analysis of the antioxidant additive octyl (4-hydroxy-3,5-di-tert-butylphenyl)propionate in an oil lubricant matrix was carried out by DESI-MS in the presence of 2-(pentyloxy)ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate as an internal standard. A quadrupole/time-of-flight mass spectrometer fitted with an in-house modified ion source enabling non-proximal DESI-MS was used for the analyses. RESULTS An eight-point calibration curve ranging from 1 to 80 μg/spot of octyl (4-hydroxy-3,5-di-tert-butylphenyl)propionate in an oil lubricant matrix and in the presence of the internal standard was used to determine the quantitative response of the DESI-MS method. The sensitivity and repeatability of the technique were assessed by conducting replicate analyses at each concentration. The limit of detection was determined to be 11 ng/mm additive on spot with relative standard deviations in the range 3-14%. CONCLUSIONS The application of DESI-MS to the direct, quantitative surface analysis of a commercial lubricant additive in a native oil lubricant matrix is demonstrated

Direct analysis of oil additives by high-field asymmetric waveform ion mobility spectrometry-mass spectrometry combined with electrospray ionization and desorption electrospray ionization

© 2016 American Chemical Society. The analysis of corrosion inhibitors in the presence and absence of an oil matrix is reported using electrospray ionization (ESI) and desorption electrospray ionization (DESI), hyphenated with miniaturized high-field asymmetric waveform ion mobility spectrometry (FAIMS) and mass spectrometry (MS). The target analytes were successfully ionized in solution by ESI and directly from steel surfaces using DESI ambient ionization at levels ≥0.0004% w/w (4 ppm) in oil. Differences in the mass spectral profiles observed for the additive/oil mixture are attributed to differences between the ESI and DESI ionization processes. The use of FAIMS improved selectivity for ESI generated analyte ions through reduction in the chemical noise resulting from the oil matrix. DESI enabled the direct, rapid, native state interrogation of oil samples on steel surfaces without sample pretreatment, and the hyphenation of DESI with the miniaturized FAIMS enhanced the relative analyte responses of the surface-active corrosion inhibitors

‘There’s no helpline’: how mental health services can support young people with climate distress

Climate distress in young people is very likely to increase in coming years, and young people’s mental health services need to be prepared to meet the demand. This paper reports a qualitative pilot study to establish the views of three stakeholder groups involved in youth mental health counselling services in England: young people, mental health counsellors, and strategic partners. We find broad agreement amongst youth mental health service users and providers that climate distress comprises a range of emotional responses to climate change, including anxiety, hopelessness, isolation, guilt and injustice, exacerbated by developmental, social and informational contexts. Service providers can support young people by surfacing, validating, and channelling these emotional responses, but they themselves need training and support to do this effectively

Steroid based toroidal facial amphiphiles

The fields of anion recognition and anion transport are active areas of research within supramolecular chemistry. This project utilised choiic acid as an advanced starting material to produce a family of macrocyclic oligosteroids. The aim was to apply these novel materials to three separate supramolecular applications; firstly, to bind anions, secondly, to form pseudorotaxanes of DNA, and thirdly to effect the transport of anions across membrane bilayers.EThOS - Electronic Theses Online ServiceGBUnited Kingdo