UHPLC Method Development for Studying the Impact of Northern Growth Latitude and Environmental Factors on Tocopherols and Tocotrienols of Sea Buckthorn
Pajunen, Lumi (2023-10-09)
UHPLC Method Development for Studying the Impact of Northern Growth Latitude and Environmental Factors on Tocopherols and Tocotrienols of Sea Buckthorn
(09.10.2023)
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.
avoin
Julkaisun pysyvä osoite on:
https://urn.fi/URN:NBN:fi-fe20231101142189
https://urn.fi/URN:NBN:fi-fe20231101142189
Tiivistelmä
High-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography (UHPLC) are both techniques used to separate the components in a mixture. The most significant difference between the methods is the properties of the particle sizes filled into the used columns. When HPLC generally uses a size range from 3 to 5 µm in classical analytics, in UHPLC, the particle size generally stays at ≤ 2 µm. This allows UHPLC to utilize higher pressures, allowing for faster running times, lower solvent consumption, and better analyte separation and detection by the detector.
This thesis studied the effect of northern growth latitude and environmental factors on tocopherol and tocotrienol contents in sea buckthorn berries. The work focused on upgrading the current high-performance liquid chromatography (HPLC) method to ultra-high-performance liquid chromatography (UHPLC) and optimizing the chromatographic separation of tocopherols.
In this work, an HPLC column with a particle size of 3.0 µm was replaced with a UHPLC column with a particle size of 1.9 µm. Also, the flow rate, mobile phase, and injection volumes were optimized. By HPLC, the running time of one sample was 25 minutes, the flow rate was 2.0 ml/min, and the injection volume for the samples was 10 µl. The development of the method made it possible to reduce the running time to eight minutes, reduce the flow rate to 0.4 ml/min, and reduce the samples’ injection volume to only 2 µl.
The upgraded UHPLC method was used to study how different environmental conditions affect tocopherol and tocotrienol levels in sea buckthorn berries. As expected, the highest tocopherol concentrations were observed for α- and γ-tocopherols and the lowest for β-tocopherols. Of the tocotrienols, only α-tocotrienol was detected.
The tocochromanol content of the sea buckthorn berries grown in Kittilä was higher than those grown in Turku. The average α-tocopherol concentration for berries grown in Turku was 66.6 ± 20.4 mg/100 g, while for those grown in Kittilä, same result was 91.5 ± 32.9 mg/100 g. Average relative humidity had the most effect on the concentration of tocochromanols compounds. The variety of the berries was not crucial regarding tocochromanol content in seabuckthorn berries.
This thesis studied the effect of northern growth latitude and environmental factors on tocopherol and tocotrienol contents in sea buckthorn berries. The work focused on upgrading the current high-performance liquid chromatography (HPLC) method to ultra-high-performance liquid chromatography (UHPLC) and optimizing the chromatographic separation of tocopherols.
In this work, an HPLC column with a particle size of 3.0 µm was replaced with a UHPLC column with a particle size of 1.9 µm. Also, the flow rate, mobile phase, and injection volumes were optimized. By HPLC, the running time of one sample was 25 minutes, the flow rate was 2.0 ml/min, and the injection volume for the samples was 10 µl. The development of the method made it possible to reduce the running time to eight minutes, reduce the flow rate to 0.4 ml/min, and reduce the samples’ injection volume to only 2 µl.
The upgraded UHPLC method was used to study how different environmental conditions affect tocopherol and tocotrienol levels in sea buckthorn berries. As expected, the highest tocopherol concentrations were observed for α- and γ-tocopherols and the lowest for β-tocopherols. Of the tocotrienols, only α-tocotrienol was detected.
The tocochromanol content of the sea buckthorn berries grown in Kittilä was higher than those grown in Turku. The average α-tocopherol concentration for berries grown in Turku was 66.6 ± 20.4 mg/100 g, while for those grown in Kittilä, same result was 91.5 ± 32.9 mg/100 g. Average relative humidity had the most effect on the concentration of tocochromanols compounds. The variety of the berries was not crucial regarding tocochromanol content in seabuckthorn berries.