Method Development for Heavy Metals Analysis and its Accumulation in Pepper (Piper nigrum L.) Cultivation Area, Sarawak, Malaysia

• Main Author: Dyg Syafiznur Aisyah, Abang Ya'kub
• Format: Thesis
• Language: English; English; English
• Published: Universiti Malaysia Sarawak 2024
• Subjects: QD Chemistry
• Online Access: http://ir.unimas.my/id/eprint/44319/5/Dyg%20Syafiznur%20Aisyah%20Binti%20Abang%20Ya%E2%80%99kub.dsva.pdf; http://ir.unimas.my/id/eprint/44319/6/MasterThesis_Dyg%20Syafiznur%20Aisyah%20Binti%20Abang%20Ya%E2%80%99kub%20-%20%2024%20pages.pdf; http://ir.unimas.my/id/eprint/44319/7/MasterThesis_Dyg%20Syafiznur%20Aisyah%20Binti%20Abang%20Ya%E2%80%99kub.ftext.pdf; http://ir.unimas.my/id/eprint/44319/

A method of ICP-MS/MS for the determination of heavy metals in black pepper berries based on microwave-assisted digestion method was established in this study. The method was optimised by optimising gas flow rate, digestion temperature, digestion power, and acid digestion system. The optimisation was successful with satisfactory recoveries between 98.14-114.83%. LOD for As, Pb, Hg, Cd and Sb were established at 0.006, 0.01, 0.003, 0.003 and 0.008 mg/kg respectively. Good linearity was observed with correlation factor (R2) above 0.999 for all the metals of interests. Uncertainties of the method were in the range of 7.21 – 18.29%. The optimised method was then applied to 115 randomly selected imported and domestic pepper berries where 53.91% of the samples analysed were found to contain As (0.01 – 7.00 mg/kg), Pb (0.01 – 3.61 mg/kg) and Cd (0.02 – 1.37 mg/kg). The method is further used to determine uptake of heavy metal in pepper cultivated in Sarawak and heavy metal concentration in compartments of pepper vines. All target elements’ concentration in parts of pepper vines, berries and soils collected from the south, middle and north region of Sarawak were found to be below the maximum allowable limit recommended by relevant standard. This shows that the pepper berries collected in Sarawak were completely safe for consumption and soils used in the cultivation area were safe for agriculture use. The value of EF and TF recorded were lower than 1, which shows that there were no hyper accumulations of heavy metals in pepper vines. Non-carcinogenic (ADD, HQ and HI) and carcinogenic (LCR and CRt) calculated shows that there were risk by consumption of pepper presents in local adults. PCA shows clustering between pepper berries and soil samples from the same region, but no clustering involving concentration of heavy metals and its location in pepper leaves and stem. Statistical analysis (ANOVA) was applied on the samples and there was significant difference between the average concentrations of target elements against area of sampling.