Nicotine is an alkaloid found in Solanaceae plants (including tobacco). Alkaloids are a class of nitrogen-containing basic organic compounds found in nature, exhibiting properties similar to bases. Examples of alkaloids include ephedrine, caffeine, and atropine.
When people smoke, they inhale nicotine, which is then transported through the bloodstream and crosses the blood-brain barrier, taking an average of just 10 seconds to reach the brain. This triggers the release of dopamine and other neurotransmitters, causing feelings of pleasure and excitement. However, this effect quickly fades, leading to irritability and restlessness when not smoking. Consequently, the natural craving to smoke again arises. Objectively speaking, nicotine is largely responsible for the addictive nature of smoking.
Nicotine poses certain hazards, but currently, there are relatively few methods for detecting it. This article will provide a method for nicotine detection and briefly share the development strategies for this method.
There are very few existing methods for detecting nicotine. When using conventional C18 columns for analysis, nicotine retention on the C18 column is very weak, making quantification difficult. However, during mass spectrometry analysis using a positive ESI source under acidic conditions, nicotine becomes positively charged. This allows for the use of ion exchange mode for analysis.
We chose the Welch zwitterionic chromatography column (the reasons for selecting this column are explained at the end of the article) and explored the experimental conditions as follows:
Experimental Conditions
- Chromatography Column: UItisil® DLC UHPLC HILIC Amphion II (2.1×100mm, 1.8μm)
-
Mobile Phase:
- A: 10 mmol/L ammonium formate solution
- B: Acetonitrile
- Column Temperature: 30°C
- Flow Rate: 0.3 mL/min
- Injection Volume: 5 μL
Chromatography Conditions:
Time(min) | Phase A% | Phase B% |
0 | 20 | 80 |
15 | 20 | 80 |
Mass Spectrometry Conditions:
- Ion Source: ESI+
- Detection Mode: MRM
- Drying Gas: Nitrogen, 400°C
- Flow Rate: 1000 L/hr
- Collision Gas: Argon
- Ion Spray Voltage: 3 kV
Names |
Parent Ion(m/z) |
Daughter Ion(m/z) |
Cone(V) |
Collision(V) |
Polarity |
Nicotine | 163.2 | 106.1 | 38 | 12 | Positive |
117.1 | 28 | ||||
132.1 | 12 |
Spectrum
Conclusion
Under these conditions, the Welch UItisil® DLC UHPLC HILIC Amphion II (2.1×100mm, 1.8μm) column enables effective analysis and detection of nicotine, showing good retention time and peak shape. As nicotine is one of the most challenging components to analyze in actual samples, successfully resolving nicotine detection also facilitates the separation of other components in the sample.
Finally, let's review the column selection process. Why is the zwitterionic chromatography column particularly suitable for this project? Let’s explore that.
HILIC Amphion II Zwitterionic Chromatography Column Profile
Separation Capability: Suitable for the separation of most polar compounds. The mobile phase typically consists of acetonitrile and water, without the need for ion-pair reagents.
Packing Structure: Contains both cationic and anionic sites, with positive and negative charge centers, which greatly enhances the retention of acidic and basic compounds through ion exchange mechanisms.
Hydrophilicity: Exhibits excellent hydrophilicity, making it suitable for separating polar, hydrophilic small molecules or basic compounds in HILIC mode.