Simultaneous quantification of seven glycols in antifreeze liquids using direct liquid injection gas chromatography coupled with mass spectrometry.

Glycol-based antifreeze liquids, commonly composed of ethylene glycol or propylene glycol, have important uses in automotive cooling, but they should be handled with care due to their toxicity. Ethylene glycol is highly toxic to humans and animals. A fast, accurate, precise, and robust method was developed for the simultaneous quantification of seven most important glycols and their isomers. METHODS: Glycols were analyzed from diluted sample solution of coolants using gas chromatography coupled with mass spectrometry (GC-MC) in single ion monitoring mode. RESULTS: The method was developed and validated for seven individual glycols (ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol). Limits of detection (1-2 µg/mL) and limits of quantification (10 µg/mL) obtained were appropriate. The present method was applied for the determination of glycols in 10 different antifreeze liquids commercially available on the Romanian market, proving to be reliable. CONCLUSIONS: A method that requires only a two-step dilution of antifreeze samples combined with direct liquid injection GC-MS was validated for the simultaneous quantification of seven glycols (and their isomers) in 10 different types of antifreeze liquids. The results obtained in the validation procedure proved that the GC-MS method is sensitive and precise for the quantification of glycols.

CO2 supercritical extraction and microencapsulation of oleoresins from rosehip fruits for getting powders with multiple applications.

The supercritical fluids extraction (SFE) was used to extract the oleoresins from rosehip, followed by an in-depth phytochemical analysis and the development of two design-customized powders for different food and pharmaceutical applications. The SFE experiments allowed obtaining an oleoresins extraction yield of 11.85%. Two fractions were separated (S40 and S45), with significantly different phytochemical profile (p < 0.05), highlighting the efficiency of extraction of fatty acids in S40 extract, whereas the extraction of polyphenols, phytosterols, carotenoids and polyphenols was favored in S45 extract. The phytochemical profile revealed that the linoleic acid (C18:2) and α-linolenic acid (C18:3) represented approximatively 82% and 58% from the total fatty acid content in S40 and S45, respectively. α-Tocopherol and γ-tocopherol prevailed in both extract fractions, with a higher concentration in S45 (229.66 mg/g dry matter (DM) and 112.36 mg/g DM, respectively), whereas ß-sitosterol was the major phytosterol in S45 fraction (118.75 mg/g DM). The S40 fraction was used to design two microencapsulated powders, by combining emulsification, complex coarcevation and freeze-drying. In order to develop new wall materials, with unique properties, the soy protein isolates were used for cross-linked reactions, by using an approach in one step (transglutaminase mediated) (coded as N) and two-steps (heat-induced and transglutaminase mediated) (coded as T). The N powder showed a better phytochemical content, leading to a higher antioxidant activity (5.27 mM Trolox equivalents/g DM), whereas for variant T, the bioactive were apparently doubled encapsulated.

Early detection of cannabinoids in biological samples based on their affinity interaction with the growth hormone secretagogue receptor.

Herein we report on the early detection of cannabinoids in urine samples according to their affinity profiles in competitive assays with labelled ghrelin (GHR). We have demonstrated for the first time that cannabidiol (CBD) and 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid (carboxy-THC) act as extracellular ligands for the growth hormone secretagogue receptor (GHS-R1a), strongly promoting the binding of ghrelin (GHR), the endogenous ligand of GHS-R1a. The affinity profiles of CBD and carboxy-THC are significantly different from the profiles of synthetic GHR mimetics such as CJC-1295 or [D-Arg1-D-Phe5-D-Trp7,9-Leu11]-Substance P peptides, which are the most common interferents; the cannabinoids promoted the GHR/GHS-R1a interaction, while the ghrelin mimetics acted rather as competitive inhibitors. The analysis of 1:4 diluted urine samples proved that the proposed method displays good linearity and sensitivity in the range of 5-30 ng/mL for both CBD and carboxy-THC, whereas GHR mimetics display no interference at concentrations up to 100 ng/mL. The results were validated by comparison with the gas chromatography tandem mass spectrometry reference method. CBD may exert the same promoting effect on the interaction of GHS-R1a with other GHR mimetics listed as performance-enhancing substances.

Whey Proteins Isolate-Based Biopolymeric Combinations to Microencapsulate Supercritical Fluid Extracted Oleoresins from Sea Buckthorn Pomace.

In this study, high-value, carotenoid-rich oleoresin obtained by supercritical carbon dioxide (SFE-CO2) extraction was used to develop five variants of microencapsulated delivery system, based on whey proteins isolate (WPI), in combination with inulin (I), pectin (P) or lactose (L). The WPI:I and WPI:L variants were also obtained by conjugation via Maillard reaction. The microencapsulation of the SFE-CO2 sea buckthorn pomace oleoresin was performed by emulsion, complex coacervation and freeze-drying, which allowed for the obtaining of five powders, with different phytochemicals profile. The WPI:I conjugate showed the highest level of total carotenoids, whereas the counterpart WPI:L showed the highest content in linoleic acid (46 ± 1 mg/g) and palmitoleic acid (20.0 ± 0.5 mg/g). The ß-tocopherol and ß-sitosterol were identified in all variants, with the highest content in the conjugated WPI:L variant. Both WPI:L and WPI:I conjugate samples presented similar IC50 value for inhibitory activity against pancreatic lipase and α-amylase; the highest activity was observed for the conjugated WPI:I. The WPI:P combination allowed the highest release of carotenoids in the gastro-intestinal environment. All the powders exhibited poor flowing properties, whereas water activity (aw) ranged from 0.084 ± 0.03 to 0.241 ± 0.003, suggesting that all variants are stable during storage. In case of solubility, significant differences were noticed between non-heated and glycated samples, with the highest value for the WPI:I and the lowest for glycated WPI:I. The structural analysis revealed the presence of finer spherosomes in WPI:I and WPI:L, with a reduced clustering capacity, whereas the particles in the conjugated samples were more uniform and aggregated into a three-dimensional network.

CO2 Supercritical Fluid Extraction of Oleoresins from Sea Buckthorn Pomace: Evidence of Advanced Bioactive Profile and Selected Functionality.

The processing of sea buckthorn generates a significant amount of pomace, seeds and skin considered valuable sources of health-promoting macromolecules, such as carotenoids, pectin, flavonoids, phytosterols, polyunsaturated fatty acids and tocopherols. In this study, the bioactives from sea buckthorn pomace (SBP) were extracted using supercritical carbon dioxide (SFE-CO2), at different temperatures and pressures, allowing for obtaining four fractions according to separators (S40 and S45). The highest carotenoid content of 396.12 ± 1.02 mg/g D.W. was found in the S40 fraction, at extraction parameters of 35 °C/45 MPa, yielding an antioxidant activity of 32.10 ± 0.17 mMol TEAC/g D.W. The representative carotenoids in the extract were zeaxanthin, ß-carotene and lycopene, whereas all enriched SFE-CO2 extracts contained α-, ß- and δ-tocopherol, with α-tocopherol representing around 82% of all fractions. ß-sitosterol was the major phytosterol in the fractions derived from S45. All fractions contained significant fatty acids, with a predominance of linoleic acid. Remarkably, the enriched extracts showed a significant palmitoleic acid content, ranging from 53 to 65 µg/g. S40 extracts showed a good antibacterial activity against Staphylococcus aureus and Aeromonas hydrophila ATCC 7966, whereas S45 extracts showed a growth inhibition rate of 100% against Aspergillus niger after three days of growth. Our results are valuable, and they allow identifying the different profiles of extracts with many different applications in food, pharmaceutics, nutraceuticals and cosmeceuticals.

Early Detection of Growth Hormone Secretagogue Receptor Antagonists Exploiting Their Atypical Behavior in Competitive Assays.

We report the proof-of-concept of a bioaffinity format designed for the early detection of growth hormone secretagogue receptor (GHS-R1a) antagonists in urine samples. We exploit here their atypical behavior in competitive experiments with labeled ghrelin (GHR), namely, the strong promoting effect on the GHR/GHS-R1a interaction at low molar ratios GHR/antagonist. The antagonists potentiate the GHR/GHS-R1a interaction, and they display the same effect on the interaction of GHS-R1a with other agonists listed as doping agents. The developed assay allows the estimation of affinity constants of ligand/receptor and antagonist/receptor binding and is amenable to optical, electrochemical, and mass-sensitive detection. The estimated affinity constants for GHR/GHS-R1a and antagonist/GHS-R1a in the absence of G proteins are in good agreement with recently reported data.