BACKGROUND The foraging choices of honey bees are influenced by many factors, such as floral aroma. The composition of volatile compounds influences the bioactivity of the aromatic plants and honey produced from them. In this study, Agastache rugosa was evaluated as part of a project to select the most promising medicinal plant species for production of bioactive honey. METHODS Headspace soli...

This research presents the results of a series of stability studies on freeze-dried formulations of human growth hormone (hGH). Chemical decomposition via methionine oxidation and asparagine deamidation as well as irreversible aggregation are characterized by HPLC. Water sorption isotherms, DSC thermograms, and pulsed proton NMR data are also obtained. No glass transition temperatures are obser...

The application of headspace solid phase microextraction (SPME) for flavor analysis has been studied. Headspace SPME sampling was tested for nine common wine flavor compounds in 10% (v/v) aqueous ethanol: linalool, nerol, geraniol, 3-methyl-1-butanol, hexanol, 2-phenylethanol, ethyl hexanoate, ethyl octanoate, and ethyl decanoate. The chemical groups (monoterpenoids, aliphatic and aromatic alco...

Accelerated stability studies of pharmaceutical products are commonly conducted at various combinations of temperature and relative humidity (RH). The RH of the sample environment can be controlled to set points using humidity-controlled stability chambers or via storage of the sample in a closed container in the presence of a saturated aqueous salt solution. Herein we report an unexpected N-ni...

An automated extraction and determination method for the gas chromatography (GC)-mass spectrometry (MS) analysis of amphetamine-related drugs in human urine is developed using headspace solid-phase microextraction (SPME) and in-matrix derivatization. A urine sample (0.5 mL, potassium carbonate (5 M, 1.0 mL), sodium chloride (0.5 g), and ethylchloroformate (20 microL) are put in a sample vial. A...

Two samples of oak honeydew honey were investigated. Headspace solid-phase microextraction (HS-SPME) combined with GC and GC/MS enabled identification of the most volatile organic headspace compounds being dominated by terpenes(mainly cis- and trans-linalool oxides). The volatile and less-volatile organic composition of the samples was obtained by ultrasonic assisted extraction (USE) with two s...

During simulation-type biodegradation tests, volatile chemicals will continuously partition between water phase and headspace. This study addressed how (1) this partitioning affects test results and (2) can be accounted for by combining equilibrium partition and dynamic biodegradation models. An aqueous mixture of 9 (semi)volatile chemicals was first generated using passive dosing and then dilu...

OBJECTIVE Access to Allied Psychological Services (ATAPS) was introduced in 2001 by the Australian Government to provide evidence-based psychological interventions for people with high prevalence disorders. headspace, Australia's National Youth Mental Health Foundation, was established in 2006 to promote and facilitate improvements in the mental health, social wellbeing and economic participati...

In this present study, it was aimed to determine the composition of essential oil obtained by water distillation from aerial parts Origanum acutidens. The analysed GC-FID and GC/MS. Carvacrol (69.3%), p-cymene (8.3%), y-terpinene (6.3%), β-caryophyllene (2.7%) borneol (2.2%) were found as main constituents. addition, headspace-solid phase microextraction using a Polydimethylsiloxane-Divinylbenz...

A multiple headspace extraction (MHE) method using the Agilent 7697A Headspace Sampler coupled with an Agilent 7890A Gas Chromatograph has been developed for quantitative determination of residual monomers and solvents in polystyrene pellets. The polystyrene pellets were freeze-ground before analysis by the MHE procedure. The optimization of headspace temperature and time for sample equilibrati...