Search results for "liquid chromatography"
showing 10 items of 942 documents
Increasing Yield and Antioxidative Performance of Litchi Pericarp Procyanidins in Baked Food by Ultrasound-Assisted Extraction Coupled with Enzymatic…
2018
Extraction with organic solvents is a traditional method to isolate bioactive compounds, which is energy-wasting and time-consuming. Therefore, enzyme and ultrasound treatments were combined to assist the extraction of oligomeric procyanidins from litchi pericarp (LPOPC), as an innovative approach to replace conventional extraction methods. Under optimum conditions (enzyme concentration 0.12 mg/mL, ultrasonic power 300 W, ultrasonic time 80 min, and liquid/solid ratio 10 mL/g), the yield of LPOPC could be improved up to 13.5%. HPLC analysis indicated that the oligomeric procyanidins (OPC) content of LPOPC from proposed extraction was up to 89.6%, mainly including (&minus
A fast liquid chromatography-mass spectrometry method combined with linear discriminant analysis for the characterization of extra virgin sicilian ol…
2008
UV filters: From sunscreens to human body and the environment
2007
Recognition of the harmful effects of ultraviolet (UV) radiation on the skin has triggered development of organic chemicals (commonly referred as UV filters) that can absorb UV radiation and attenuate the negative effects of sunlight exposure. Depending on the properties and the intended degree of protection, a wide array of combinations is being marketed as delivering protection against most kinds of UV-induced skin damage. However, some UV filters have dermatological implications, so maximum applicable concentrations have been established. To monitor to what extent commercial products comply with the mandatory limits, several analytical methods have been used for their determination in co…
Development of fast analysis methods for extractives in papermaking process waters
2011
A fast analysis method with an online sample enrichment technique for the analysis of resin and fatty acids present in papermaking process waters was developed. This method was based on atmospheric pressure chemical ionization (APCI) and mass spectrometry (MS) for the detection of [M-H]- ions of compounds of interest. The method was applied to the control of the most prevalent resin (dehydroabietic and abietic) and fatty (palmitic, stearic, oleic, and linolenic) acid levels in papermaking process waters. Continuous data on these acids are of practical importance when predicting possible deposit-derived problems in the paper machine. The first part of the study was focused on the development…
Polyphenols and Pharmacological Screening of a Monarda fistulosa L. dry Extract Based on a Hydrodistilled Residue By-Product
2021
This study aimed to determine the composition and content of polyphenols in the dry extract obtained from the hydrodistilled residue by-product of the wild bergamot (Monarda fistulosa L., Lamiaceae Martinov family) herb (MFDE) and to evaluate its safety and pharmacological properties. The total phenolic content (TPC) in the MFDE was 120.64 mg GAE/g. The high-performance liquid chromatography (HPLC) analysis showed the presence of a plethora of phenolic compounds, including hydroxycinnamic acids and flavone derivatives in the MFDE, with rosmarinic acid and luteolin-7-O-glucoside being the main components. With an IC50 value of 0.285 mg/mL, it was found to be a strong DPPH radical scavenger. …
Assays for detection of fungal hallucinogens such as psilocybin and psilocin
2016
Methods applicable to the detection of hallucinogenic indole compounds, namely psilocybin, psilocin, and related molecules, that have been developed so far for purposes of mycological research, toxicological studies, or forensic investigations are described in this chapter. The most current literature as well as some interesting older publications are cited, providing a historical overview of the subject. Methods of qualitative and quantitative analysis are presented. Additionally, preliminary purification steps and sample treatment before the exact quantitative determination are proposed. The methods described utilized various analytical techniques for the measurement of psilocybin/psiloci…
Data set: Towards a rapid screening of liver grafts at the operating room using mid-infrared spectroscopy
2020
The estimation of steatosis in a liver graft is mandatory prior to liver transplantation, as the risk of graft failure increases with the level of infiltrated fat. However, the assessment of liver steatosis before transplantation is typically based on a qualitative or semi-quantitative characterization by visual inspection and palpation, and histological analysis. Thus, there is an unmet need for transplantation surgeons to have access to a diagnostic tool enabling an in situ fast classification of grafts prior extraction. In this study, we have assessed an Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopic method compatible with the requirements of an operation…
Data set: Towards a rapid screening of liver grafts at the operating room using mid-infrared spectroscopy
2020
The estimation of steatosis in a liver graft is mandatory prior to liver transplantation, as the risk of graft failure increases with the level of infiltrated fat. However, the assessment of liver steatosis before transplantation is typically based on a qualitative or semi-quantitative characterization by visual inspection and palpation, and histological analysis. Thus, there is an unmet need for transplantation surgeons to have access to a diagnostic tool enabling an in situ fast classification of grafts prior extraction. In this study, we have assessed an Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopic method compatible with the requirements of an operation…
Data set: Towards a rapid screening of liver grafts at the operating room using mid-infrared spectroscopy
2020
The estimation of steatosis in a liver graft is mandatory prior to liver transplantation, as the risk of graft failure increases with the level of infiltrated fat. However, the assessment of liver steatosis before transplantation is typically based on a qualitative or semi-quantitative characterization by visual inspection and palpation, and histological analysis. Thus, there is an unmet need for transplantation surgeons to have access to a diagnostic tool enabling an in situ fast classification of grafts prior extraction. In this study, we have assessed an Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopic method compatible with the requirements of an operation…
Determination of glyphosate and its metabolite aminomethylphosphonic acid in fruit juices using supported-liquid membrane preconcentration method wit…
2005
Abstract The application of supported-liquid membrane (SLM) technique for effective extraction of N -(phosphonomethyl)glycine (glyphosate) and its primary metabolite aminomethylphosphonic acid (AMPA) from juices (orange, grapefruit, apple and blackcurrant) in combination with HPLC-UV detection after derivatization with p -toluenesulphonyl chloride (TsCl) is presented. The influence of various parameters such as the composition of acceptor phase, flow-rate, concentration of analytes, on the performance of extraction procedure, was studied. It was shown that by appropriate manipulation of SLM parameters the level of detection could be significantly improved. The influence of SLM conditions on…