Determination of Some Common Heavy Metals and Radionuclides in Some Medicinal Herbs Using ICP-MS/MS

Medicinal herbs are the ancient, traditional way of treating many diseases and are now considered the first natural source of pharmaceutical active ingredients. Therefore, it is very important to focus on the hygiene of these plants so as to make sure they are safe for consumption. This work aimed to monitor the common heavy and radioactive elements in some commonly used herbs: anise, chamomile, clover, cumin, coriander, fennel, roselle, rosemary, sage, and thyme. A total of 12 elements were measured including 2 radionuclides, Al, As, Cd, Hg, Co, Cr, Ni, Pb, Sr, Th, U, and V. Heavy metals are ecologically and biologically important, and may be involved in some health disorder symptoms within the human body. Samples were digested with a microwave digester and measurements were completed with ICP-MS/MS in Helium mode to increase sensitivity, lower the background, and avoid interferences. Method validation and verification were performed through the spiking process at 2.0 µg/kg level, and then RSD, LOD, and LOQ were calculated. Recoveries ranged from 93–103% for all elements and RSD% from 2.8–9.6%. Hg and Th were not detected in all samples, while U was detected in some sample of anise, rosemary, sage, and thyme, and ranged from 0.018–0.048 mg/kg. As was detected in anise, fennel, roselle, and rosemary, and ranged from 0.0.031–5.88 mg/kg. Al, Cd, Co, Cr, Ni, Pb, Sr, and V were detected in most samples of all herbs, and ranged from 3.88–17.80, 0.122–0.654, 0.019–0.851, 0.344–2.91, 1.872–5.82, 0.120–12.56, 0.128–0.844, and 0.083–0.912 mg/kg, respectively.