Was it a good encapsulation? Vadoud Niri, assistant professor and director of the chemistry graduate program at State University of New York—Oswego , holds a PhD in analytical chemistry. Besides teaching analytical chemistry courses at both undergraduate and graduate levels, his research group in the Analytical Chemistry Research Lab ACRL focuses on developing new analytical methods for analyzing different types of compounds in a variety of environmental, biological, and food samples.
A: The current projects where we use headspace analysis are as follows: Analyzing high molecular weight alcohols and flavors from Scotch samples from different regions of Scotland, analyzing microbial volatile organic compounds MVOCs from mold samples to develop a method for early detection of mold growth, and analyzing fragrances from plants used for extracting essential oils.
A: One of the important aspects of headspace analysis is reducing sample preparation steps, especially for samples with complicated matrices. So using the headspace method, in most cases, saves us sample preparation time and provides cleaner results.
A: Headspace analysis works effectively for analyzing volatile compounds; however, it can be challenging for semi-volatile or non-volatile compounds. A: In the case of semi-volatile compounds, increasing the temperature is the easiest way to solve this problem. This approach has its own limitations based on the sampling method used. For example, if you are using solid-phase microextraction for extraction from a headspace, increasing the temperature will be useful until some point; after that, the extraction efficiency will go down because of increasing desorption from the fiber at the higher temperature.
In this case, we usually find an optimal temperature by plotting the temperature profile. A: Papers by other researchers in this area, both published as articles or presented at a conference, are great sources to find new improvements in this area.
The experience that we get in the lab over time teaches us a great deal. A: Time is always money! Shortening analytical methods can save huge [amounts of] time and expenses, especially when we are dealing with a large number of samples. We are also looking to lower the detection limits of analytical methods [in order] to be able to analyze lower concentrations.
Related Articles. It all taste so good. Volatile sample components diffuse into the gas phase, forming the headspace gas.
Headspace analysis is therefore the analysis of the components present in that gas. Dynamic headspace is done to increase the headspace sample size, thus, the sensitivity of the technique. DHS is best used for analysis of heavy molecular weight materials, such as plasticizers. Therefore, reproducibility of sample preparation is important with heating, agitation rate, and the ratio of the sample volume or weight to the headspace gas volume being critical for optimum, reproducible results.
The headspace gas can be sampled manually using a heated gas tight syringe to avoid condensation or by using an automated system employing a heated gas loop which transfers the sample to the GC column via a heated transfer line. February 29, Question: Why would headspace GC be a good sampling technique?
Typical examples of headspace analyses include: Volatile Organic Compounds VOC from wastewater and contaminated land samples Residual solvents in packaging and pharmaceuticals Blood alcohol and toxicology screening. Answer: Headspace GC is amenable to the analysis of both liquids and solids. References K. Karthikeyan et al. Hollender and E. Hammersley, Chromatography Today 30
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