Related Experiment Video
Updated: Jan 28, 2026
06:19
Chinese Herbal Retention Enema for the Treatment of Ulcerative Colitis
Published on: May 16, 2025
1.4K
Retrieval of structure information from retention index
1Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco 94143-0446.
Journal of Chromatography. A
|September 2, 1994
Summary
This study introduces a new method using chromatographic parameters like Kováts retention index and column difference to determine compound identity and retrieve structural information. This approach uniquely utilizes gas chromatography retention characteristics for structure elucidation.
Area of Science:
- Analytical Chemistry
- Chromatography
- Physical Chemistry
Background:
- Chromatographic retention data, specifically Kováts retention index (I), is crucial for compound identification.
- Retrieving structural information from retention data requires a deeper understanding of the factors influencing chromatographic behavior.
Purpose of the Study:
- To develop a system for uniquely utilizing gas chromatography (GC) retention characteristics for structure elucidation.
- To redefine the Kováts retention index and introduce new parameters for enhanced structural information retrieval.
Main Methods:
- Utilizing four parameters: I, A, Z, and (GRF), interrelated by a linear regression equation.
- Separating retention index (I) into molecular and interaction contributions.
- Defining column difference (delta I) to characterize functional groups and their interactions with the stationary phase.
Main Results:
- The retention index is uniquely determined by parameters A, Z, and (GRF).
- Pre-calibrated terms (m and n) account for polar and polarizable atom group contributions to retention.
- Column difference (delta I) reflects interaction strength and is characteristic of functional/polarizable groups.
Conclusions:
- A system can be devised to uniquely utilize GC retention characteristics for structure elucidation.
- Retrieving structural information from retention data is straightforward for monofunctional compounds but requires additional data for multifunctional compounds.
Related Concept Videos
01:05Bioavailability Enhancement: Drug Stability Enhancement and GI Retention
206
Body:Improving a drug's stability in the gastrointestinal (GI) tract is paramount for enhancing its bioavailability and therapeutic effectiveness. Various strategies are employed to protect the drug from the harsh gastric milieu and to ensure its release and absorption at the desired site within the GI tract.Polymer coatings are one such method used to shield drugs from the stomach's acidic environment. By preventing premature drug release, these coatings improve the bioavailability of unstable...
206
01:12Retrieval
435
Retrieval is the process of getting information out of memory storage and back into conscious awareness. This ability is essential for daily tasks like brushing hair and teeth, driving to work, and performing job duties. Retrieval occurs in three ways: recall, recognition, and relearning.
Recall involves accessing information without cues, such as during an essay test, where individuals must retrieve facts and concepts from memory unaided. Another example is remembering the name of a colleague...
Recall involves accessing information without cues, such as during an essay test, where individuals must retrieve facts and concepts from memory unaided. Another example is remembering the name of a colleague...
435
01:45ER Retrieval Pathway
4.8K
In the secretory pathway, vesicles transport proteins from one cellular compartment to another in forward transport to deliver the protein to its correct location. Occasionally, misfolded proteins and incorrect proteins escape their original compartments, and a retrieval pathway is used to return the escaped proteins to their original compartment.
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
4.8K
02:41Chromatin Structure Regulates pre-mRNA Processing
8.2K
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
8.2K
02:22Structures of Solids
17.7K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
17.7K
02:34Structural Isomerism
21.7K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
21.7K