ESR8 Jawameer Hama

Project: Quantification of crop produced natural toxins in groundwater

Principal supervisor: Dr. Bjarne W. Strobel

The project: The aim was to study the environmental fate of natural alkaloids - phytotoxins, with a focus on locate alkaloids producing vegetation areas, explain the occurrence of the toxins in the plants, soil and surface water, in relation to seasonal and microclimate variation. For that, alkaloids from ragwort (Jacobaea vulgaris), butterbur (Petasites sp.), lupin (Lupinus spp.) and soybean [Glycine max (Merr.) L.] were targeted and their environmental fate investigated.

During the project, two sampling campaigns focused on pyrrolizidine alkaloids (PA)s, where 3 ragwort (Jacobaea vulgaris) were selected in Denmark, and studied in 1 year period, with additional  butterburs (Petasites sp.) site was selected in Denmark, and studied over 4 months period. Another campaigns focused on alkaloids and phytoestrogens from soybean [Glycine max (Merr.) L.] in Iowa, USA – during soybean growth and 4 months after the harvest.  Two agricultural field conducted (Denmark and Switzerland) and focused on the fate of alkaloids from lupin (Lupinus spp.). Lab studies on sorption and degradation of alkaloids in soil and water conducted. An analytical method was developed to quantify alkaloids in plants, soils and waters.

Major conclusions
PAs were continuously detected and quantified, where ragwort was the source and expected to contain average 506 kg PAs/ha, their load in soil and pond - surface water were 1.7 kg/ha and 5 g/10000 L, respectively. [1] In addition, in surface water and shallow groundwater wells (2.2–3.0 m depth), adjacent to butterbur plants PAs were detected, the total concentrations were 0.53 and 0.23 μg/L, respectively. However, in deep groundwater (~60 m depth) no PAs were detected. [2]  

Overall, during the field experiments, lupin biomass and alkaloid contents increased toward the harvest season. In lupin field-Switzerland, lupin plant biomass and density were 22.9 g (dry weight (dw) per plant) and 30±4 per m², respectively, this lead to have 6.9x10³ kg dw/ha of lupin production and 4.0 to 11.1 kg/ha of total alkaloids in lupin, per season. During the field experiment 0.55 kg/ha of total alkaloids transported to topsoil (10 cm), also cumulative loads emitted via drainage water were around 0.2-9 mg/ha for individual alkaloids, and 13 mg/ha for total alkaloids.

In the water samples collected from September 2019 to March 2020 in Iowa Midwestern US, alkaloids and phytoestrogens were detected with concentrations ranged from no detection to 37 and 40 ng/L, respectively; alkaloids detected more frequently. They were transported from soybeans field to soil and to proximal surface water.

LC-MS/MS method allowed direct and simultaneous quantification of alkaloids for the first time in the environmental samples. The method limit of detection (LOD) for alkaloids ranged from 0.001 µg/L to 7 µg/L. [3, 4]

References:

1. Hama, J.R. and Strobel, B.W., 2020. Occurrence of pyrrolizidine alkaloids in ragwort plants, soils and surface waters at the field scale in Grassland. Science of The Total Environment, 755, p.142822.
2. Kisielius, V., Hama, J.R., Skrbic, N., Hansen, H.C.B., Strobel, B.W. and Rasmussen, L.H., 2020. The invasive butterbur contaminates stream and seepage water in groundwater wells with toxic pyrrolizidine alkaloids. Scientific reports, 10(1), pp.1-10.
3. Hama, J.R. and Strobel, B.W., 2020. Natural alkaloids from narrow-leaf and yellow lupins transfer to soil and soil solution in agricultural fields. Environmental Sciences Europe, 32(1), pp.1-12.
4. Hama, J.R. and Strobel, B.W., 2019. Pyrrolizidine alkaloids quantified in soil and water using UPLC-MS/MS. RSC advances, 9(52), pp.30350-30357.

Scientific profile
Jawameer received his Master degree in analytical chemistry from Bangor University (UK), 2013. His master focused on the plant metabolites and their environmental impact, in particular phenolics from walnut. Jawameer did his PhD at Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, undersupervision of Bjarne W Strobel and Dana W Kolpin. During his PhD, he investigated on the fate of phytotoxins from plants in natural and agricultural areas. He has several years experience of analytical chemistry, quality control, planning, method optimization, statistics, monitoring and fieldwork.