Prof Jaya George, Raylton Chikwati and Tracy Snyman
By Raylton Chikwati
Masters student in Clinical Biochemistry,
Department of Chemical Pathology,
University of Zimbabwe, Harare, Zimbabwe.
Having been awarded the prestigious International Federation of Clinical Chemistry Professional Exchange Program Scholarship (IFCC PSEP), I spent three months (21 November 2016 to 18 February 2017) at the National Health Laboratory Services Development Laboratory, Department of Chemical Pathology, University of Witwatersrand, Johannesburg, South Africa. Professor Jaya George (Head of Department) and Ms Tracy Snyman, (Laboratory Unit Supervisor), were my immediate mentors. I received their warmest reception and guidance throughout the program.
During my stay I was trained in High Pressure Liquid Chromatography (HPLC) techniques, a separation method used in measuring specific substances from a sample mixture based on their differential migration in a column. My work focused on vitamin D measurement using HPLC as part of my Masters research project investigating the impact (if any) of maternal vitamin D status in HIV infection, birth outcomes and infant anthropometry on the first six months of life.
I was afforded the opportunity to learn chromatography on two HPLC platforms. The first being the one I did analysis on my study samples from Zimbabwe. For this research, I used reverse phase HPLC coupled to a photodiode array detector, for the measurement of 25 hydroxyvitamin D. On the second HPLC platform I was able to use Isotope-Dilution Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS) for the simultaneous measurement of 25 hydroxyvitamin D; 1,25 dihydroxyvitamin D; 24,25 dihydroxyvitamin D; vitamin D2 and vitamin D3 metabolites.
For the LC/MS/MS, I was involved in optimising the vitamin D assay for validation. This enabled me to learn the various components of mass spectrometry with particular emphasis on the different ionisation techniques that a scientist can utilise. These include, the electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionisation (APPI). In addition, I was able to prepare the different mobile phase mixtures for the validation, prepare calibration curves by liquid-liquid extraction of vitamin D from commercial standard samples as well as quality control materials.
Comparing the two HPLC platforms, the LC/MS/MS had a higher sensitivity and throughput, it required less sample volume and simultaneously measured more vitamin D metabolites in a given sample. On the other hand, the HPLC platform connected to a photodiode array detector had a lower throughput, required more sample volume although the sample preparation was much faster.
I was also involved in setting up validation for the measurement of steroid hormones using the LC/MS/MS. The steroid hormones that were identified include progesterone, cortisol, testosterone, dihydroepiandesterone, estradiol, follicle stimulating and the luteinizing hormone, amongst others.
I also had the opportunity to rotate on selected work benches within the laboratory and learn by observation on other routine tests offered by the lab. This included techniques in protein electrophoresis, atomic absorption, LC/MS/MS on metanephrines, normetanephrines and drug monitoring. Such exposure enhanced my practical knowledge as most of these tests are not offered at most labs in my home country.
During the PSEP I also attended journal club sessions within the Department of Chemical Pathology, where scientists and registrars presented research articles within the discipline. In addition, I attended seminars. This helped me develop my approach to critiquing journal articles and learn more on presentation skills.
I wish to express my utmost gratitude to the IFCC panel for the financial support towards my visit to the National Health Laboratory Services (NHLS) in South Africa. I also wish to extend my special appreciation to the former IFCC President, Professor Ferrari for continued support of the IFCC Professional Scientific Exchange Programme (PSEP) and believing in young researchers. I also want to appreciate Mrs. Colli-Lanzi in at the IFCC office, for invaluable communication and administration assistance when I was submitting my application and during the duration of the PSEP.
I wish to make specific mention to my host Prof. Jaya George for facilitating my coming to the NHLS lab in South Africa. I am eternally grateful for such an opportunity and her support in making this dream a reality. I’m grateful to Ms Tracy Snyman for training me on the HPLC and LC/MS/MS methods. I am indebted to the staff in the Department of Chemical Pathology who gave a warm welcome and their professionalism.
Much appreciation also goes to the Zimbabwe Association of Clinical Biochemistry (ZACB) and African Federation of Clinical Chemistry and Laboratory Medicine (AFCC) for their continued support to young scientists towards their professional development. Of particular mention is the 4th Congress of the African Federation of Clinical Chemistry and Laboratory Medicine in 2015 that was held in Harare, Zimbabwe. It is on this particular platform that I met Professor Jaya George after her presentation and was able to establish correspondence that has formed the basis of this work at the University of Witwatersrand.
2016 IFCC-PSEP scholarship recipient