نتایج جستجو برای: assisted headspace spme ua

تعداد نتایج: 139598  

Journal: :Chemija 2022

Hypericum Perforatum L., commonly known as St. John’s wort, is one of the best-known medicinal herbs. wort infused oils are mostly used externally, but can be taken orally for stomach ulcers, a food supplement. Therefore, it important to develop methods that allow rapid and reliable determination β-caryophyllene, which main active components wort. In this work, two gas chromatographic technique...

2004
Mikael Gröning

The extraction and quantitative analysis of low molar mass compounds in polymers is an analytical challenge. It is also important from a practical point of view because the low molar mass compounds in time will migrate from the polymers into the surrounding environment. It is especially important to gain knowledge about the migrating compounds in applications such as medical implants, packaging...

2010
S P Cummings A Nelson P J Purcell A De Soyza S J Bourke

chiectasis and Cystic Fibrosis clinics. The gold standard for diagnosing P. aeruginosa infection was positive sputum cultures. 72 sputum samples were analysed. A sputum sample was kept in a glass vial with a cap containing septum. The septum was pierced with a solid phase microextraction (SPME) fibre allowing sampling of the headspace for 50 min at 378C before transferring the fibre into gas ch...

Journal: :Molecules 2011
Igor Jerković Zvonimir Marijanović Mladenka Malenica Staver

Headspace solid-phase microextraction (HS-SPME; PDMS/DVB fibre) and ultrasonic solvent extraction (USE; solvent A: pentane and diethyl ether (1:2 v/v), solvent B: dichloromethane) followed by gas chromatography and mass spectrometry (GC, GC-MS) were used for the analysis of Prunus mahaleb L. honey samples. Screening was focused toward chemical composition of natural organic volatiles to determi...

Journal: :Microchemical Journal 2022

• Validation of MHS-SPME-GC-MS method for the analysis two plasticizer metabolites. No matrix effect, no external calibration, loss, solvents free and quick method. Application to urine samples population with exposure plastics. In present work, an optimization validation analytical determination metabolites, 2-ethylhexanol 4-heptanone in urine, were carried out by multiple headspace solid-phas...

Journal: :Revista Brasileira De Fruticultura 2022

Abstract despite the high social and economic importance of Spondias tuberosa Arruda, to best our knowledge there are very few detailed studies on volatile compounds this fruit popularly named umbu. Therefore, aim study was find extraction conditions by solid-phase microextraction in headspace mode (HS-SPME) determine from umbu pulp gas-chromatography coupled mass spectrometry (GC-MS). The opti...

Journal: :Analytical chemistry 2014
Ezel Boyacı Janusz Pawliszyn

Determination of quaternary ammonium compounds (QACs) often is considered to be a challenging undertaking owing to secondary interactions of the analytes' permanently charged quaternary ammonium head or hydrophobic tail with the utilized labware. Here, for the first time, a micelle assisted thin-film solid phase microextraction (TF-SPME) using a zwitterionic detergent 3-[(3-cholamidopropyl)dime...

2010
Hamed Mirhosseini Chin Ping Tan Mahsa Naghshineh

In this study, the effect of glycerol (0.5, 1 and 1.5% w/w) and vegetable oil (2, 3 and 4% w/w) on the equilibrium headspace concentration of target volatile flavor compounds released from the orange beverage emulsions during storage was investigated by using the headspace solid phase microextraction (HS-SPME). The peak areas of 13 target orange flavor compounds (i.e. ethyl acetate, α-pinene, e...

Journal: :Journal of agricultural and food chemistry 2008
Russell L Rouseff Ebenezer O Onagbola John M Smoot Lukasz L Stelinski

Volatiles from crushed and intact guava leaves (Psidium guajava L.) were collected using static headspace SPME and determined using GC-PFPD, pulsed flame photometric detection, and GC-MS. Leaf volatiles from four common citrus culitvars were examined similarly to determine the potential component(s) responsible for guava's protective effect against the Asian citrus psyllid (Diaphorina citri Kuw...

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