GC Analysis – Part V. FID or MS for Essential Oils?
Alexis St-Gelais – Popularization [Minor addenda to the original text were made on March 23, 2019, and are noted in green] An important task of analytical chemistry is to select the detector that best suits the purpose of an analysis. Each detector has indeed its pros and cons. In the area of essential oils, FID and […]
GC Analysis – Part IV. Retention Indices
Alexis St-Gelais – Popularization I mentioned in the first post of this series on GC analyzes that PhytoChemia resorted simultaneously to two capillary columns to analyze essential oils, one polar (Solgel-Wax) and one non-polar (DB-5). The rationale behind this technique will reveal some of the art of interpreting essential oils profiles. We have seen that […]
GC Analysis – Part III. Mass Spectrometry Detection (MS)
Alexis St-Gelais – Popularization My last post gave some details about a detection method commonly used in GC, the FID. Another detector that is widely used for the analysis of volatile compounds, including at PhytoChemia, is the mass spectrometer (MS). Unlike the FID, the MS is a complex detector. Typically, in GC-MS (although other modes […]
GC Analysis – Part II. The Flame Ionization Detector (FID)
Alexis St-Gelais – Popularization The first part of this series dealt with the principles of separation of volatile molecules upon analysis by GC. After their separation, the analyst has yet to be able to detect molecules as they leave the capillary column, either to identify or quantify them. At PhytoChemia, we mainly use two types […]
Extracting Essential Oils in the Lab
Alexis St-Gelais – Popularization Many of the samples we analyze are sent to us directly as essential oils. However, sometimes a customer wishes to compare plants before their extraction. He may also need a measure of oil yield so that he can plan ahead larger extractions. In these cases, we use two main extraction techniques, each with […]
GC Analysis – Part I. Separation Principles
Alexis St-Gelais – Popularization I have explained in a previous post the main theoretical principles of chromatography. Today, I will detail one of its practical applications, widely used by PhytoChemia: gas chromatography (GC). It lends itself to the analysis of volatile molecules – that is to say molecules capable of passing to gas phase at […]
Chromatography
Alexis St-Gelais – Popularization Chromatography refers to a wide range of separation techniques, frequently used in the field of analytical chemistry . The principles of chromatography allow PhytoChemia to achieve several of its analyzes. Chromatography is, for every chemist working in organic chemistry, a valuable tool. It brings together all techniques used for separating mixtures of […]
The importance of plant identification – Part 2
Hubert Marceau – Popularization Figure 1: A. ursinum (source) In 2004, in the canton of Neufchâtel, Switzerland, clients from a restaurant who ordered fish with a bear’s garlic sauce, Allium ursinum (Figure 1), went on a painful adventure. Shortly after eating they started to have severe gastrointestinal troubles. After analysis, it was found that the sauce contained colchicine, a toxic alkaloid. […]