• Application Note

Quantitative Analysis of Phosphatidylethanolamine and Phosphatidylcholine from Rice Oil Lecithin and Sunflower Oil Lecithin by ACQUITY UPLC H-Class Plus System with PDA Detection

Quantitative Analysis of Phosphatidylethanolamine and Phosphatidylcholine from Rice Oil Lecithin and Sunflower Oil Lecithin by ACQUITY UPLC H-Class Plus System with PDA Detection

  • Dilshad Pullancheri
  • Dr. Gurubasavaraj HM
  • Bheeshmacharyulu. S
  • Padmakar Wagh
  • Shaju V A
  • Ramesh Chandran K
  • Rajeesh K R
  • Abhilash Puthiyedath
  • Waters Corporation
  • Kancor Ingredients Ltd.

Abstract

In this application note, we have developed a 15 minutes method for quantitative analysis of PE and PC on the ACQUITY UPLC H-Class Plus System with a PDA Detector.

Benefits

Quantification of PE and PC in rice and sunflower oil lecithin within 15 minutes run time on the ACQUITY UPLC H-Class Plus System with a PDA Detector.

Introduction

Phospholipids are major constituents of cell membrane and are found in all tissues and subcellular compartments as mixtures of various molecular species such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), sphingomyelin (SM), and lysophosphatidylcholine (LPC) depending on the type of polar head groups and the degree of unsaturation of the acyl chains. Among these phospholipids, PC and PE represents a major constituent of cell membranes. The demand for lecithin with high PC and PE content from vegetable or cereal source is increasing these days, particularly in pharmaceutical, cosmetic, food, and other applications due to their emulsifying properties and nonantigenic nature. The application of lecithins in pharmaceutical and cosmetics domain depends mainly on the PC and PE with its saturated or unsaturated fatty acid content.

Figure 1. Classification of phospholipids.

The present method of UltraPerformance Liquid Chromatography (UPLC) with UV detection offers advantages of high speed, resolution and simplicity for the separation and detection of phospholipids including phosphatidylcholine and phosphatidylethanolamine from rice and sunflower oil lecithin. The ultraviolet/visible spectrometer coupled with the UPLC system for the phospholipids detection has greater sensitivity over refractive index or flame-ionization detection. However, the UV detection restricts the use of common chromatographic solvents that are not transparent in 200 nm to 210 nm regions wherein phospholipids have tendency of absorbing the light energy. The Reverse Phase (RP) UPLC-UV system however can successfully engage solvents such as acetonitrile, ethanol, methanol, iso-propanol, and water. The significance of UV detection is that it has multiple choices of compositions of mobile phase to advance the isocratic or gradient elution. The available reverse phase methods are complex, laborious, and time-consuming, while this UPLC method is simple and short.

In this application note, we have developed a 15 minutes method for quantitative analysis of PE and PC on the ACQUITY UPLC H-Class Plus System with a PDA Detector.

Experimental

LC method parameters

Instrument:

ACQUITY UPLC H-Class Plus System with PDA Detector

Column:

ACQUITY UPLC BEH HILIC 1.7 μm, 100 mm × 2.1 mm

Flow rate:

0.2 mL/min

Mobile phase A:

10 mM ammonium formate and 0.05% ammonia solution in water

Mobile phase B:

Acetonitrile with 0.05% ammonia solution

Column temp.:

80 °C

Sample temp.:

15 °C

Injection volume:

10 μL

Sample concentration:

100 μg/mL for PE and 10 μg/mL for PC

Wash and purge solvent:

20:80 (Water:IPA)

Seal wash:

9:1 (water:methanol)

Diluent:

1:1 (chloroform:IPA)

PDA fixed wavelength:

205 nm

Data acquisition rate:

2 pts/sec

Figure 2. ACQUITY UPLC H-Class Plus System with an ACQUITY PDA Detector.
Table 1. Gradient program.
Table 2. Standard and sample details.

Standard solution preparation

Accurately weighed 100 mg of PC standard (75% pure) and dissolved in 10 mL of diluent as a standard stock solution I of 10,000 µg/mL concentration. 

Working standard was prepared by mixing 100 µL of standard stock solution I and 100 µL of PE standard labelled as 10 mg/mL (97% pure) and making up the volume to 1000 µL to make concentration 1000 µg/mL of each component mix.

Further dilutions for linearity were prepared by appropriate dilutions from the standard mix.

Sample preparation

10,000 µg/mL stock solutions were prepared by weighing 100 mg of each sample and dissolved in 100 mL of diluent. Two separate concentrations were prepared by further diluting the stock solution to 100 µg/mL and 10 µg/mL for PE and PC analysis respectively.

Results and Discussion

Due to the huge difference in the concentration of PE and PC present in oil lecithin samples, separate sample dilutions were prepared for PE and PC. 1000 µg/mL stock solution of samples were diluted to 100 µg/mL (10 times) and 10 µg/mL (100 times) for PE and PC respectively and quantified against the calibration curve plotted from 1 ppm to 25 ppm.

Table 3. Sample analysis results.
*All concentrations reported are with respect to 1000 ppm sample concentration and adjusted by dilution factor.
Figure 3. SFOL sample chromatogram for PE.
Table 4. Three replicate injection result table for PE in SFOL.
Figure 4. SFOLE sample chromatogram for PE. 
Table 5. Three replicate injection result table for PE in SFOLE.
Figure 5. ROL sample chromatogram for PE. 
Table 6. Three replicate injection result table for PE in ROL.
Figure 6. SFOL sample chromatogram for PC. 
Table 7. Three replicate injection result table for PC in SFOL.
Figure 7. SFOLE sample chromatogram for PC.
Table 8. Three replicate injection result table for PC in SFOLE.
Figure 8. ROL sample chromatogram for PC.
Table 9. Three replicate injection result table for PC in ROL.

Reproducibility

Reproducibility test was performed with 1 µg/mL (LOQ) concentration for PE and PC. %RSD of area observed in six replicate injections for both the components were within the limit.

Table 10. Six replicate injection result table for PC LOQ.
Table 11. Six replicate injection result table for PE LOQ.

LOQ for PE and PC

1 µg/mL (LOQ) concentration of the standard mix was injected and observed that the signal-to-noise ratio value is 30 for PE peak and 17 for PC peak.

Figure 9. LOQ chromatogram PE and PC standard mix at 205 nm. 

Recovery study for PE and PC

Recovery study was performed for PE and PC by injecting 2, 10, and 15 µg/mL concentration of standard mix in neat solution and spiked 2, 10, and 15 µg/mL of PE and PC standard mix with final concentration of three samples and observed the recovery.

Table 12. % Recovery for PE in three matrices at three different concentrations.
Table 13. % Recovery for PC in three matrices at three different concentrations.

Linearity for PE and PC

Prepared Linearity solutions of PE (97% pure) from 1 µg/mL, 2 µg/mL, 5 µg/mL, 10 µg/mL, 15 µg/mL, 20 µg/mL, and 25 µg/mL solutions and PC (75% pure) standard with different concentrations of 0.75 µg/mL, 1.5 µg/mL, 3.75 µg/mL, 7.5 µg/mL, 11.25 µg/mL, 15 µg/mL, and 18.75 µg/mL solutions and plotted calibration curve.

Table 14. Calibration curve properties.
Figure 10. Calibration curve for PE.
Table 15. Calibration curve table for PE.
Figure 11. Calibration curve for PC.
Table 16. Calibration curve table for PC.

Conclusion

  • Quantitative analysis of Phosphatidylethanolamine (PE) and Phosphatidylcholine (PC) was performed using ACQUITY UPLC H- Class Plus with PDA Detector at wavelength 205 nm.
  • UV Lowest Limit of Quantification has been set at 1ppm in neat solution (without considering standard purity) for PE and PC standards.
  • Due to the huge difference in the concentrations of PE and PC, separate sample dilutions were used for quantifying both compounds.
  • The reproducibility, accuracy, and recovery has been observed within the accepted limits.
  • All the samples have been analyzed and the concentrations are reported.

UPLC technology coupled with UV detection provides a unique solution for quantitative analysis of phosphatidylethanolamine and phosphatidylcholine from rice and sunflower oil lecithin. 

Acknowledgement

Authors wish to thank Mr. Geemon Korah, Director, CEO, and Mr. Sasheendran Vijayan, Head-Innovations, Kancor Ingredients Ltd. for their immense support for conducting the research collaboratively.

References

  1. Separation and Identification of Phosphatidylethanolamine Molecular Species, J. Lipid Res. 40:164–169 (1999).
  2. Tomlinson, E., H. Poppe, and J.C. Kraak, Thermodynamics of Functional Groups in Reversed-Phase High Performance Liquid-Solid Chromatography, Intl. J. Pharmaceut. 7:225–243 (1981).
  3. Smith, R.M., Functional Group Contributions to the Retention of Analytes in Reversed-Phase High-Performance Liquid Chromatography, J. Chromatogr. A 656:381–415 (1993).
  4. Annals of Pharmacology and Pharmaceutics Review Article Published: 21 June 2017 “Simple and Rapid Separation and Determination of Phospholipids by HPLC-UV System.”

720006715, December 2019

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