Monitoring of Some Chemical Contaminants Residue in Imported Wheat and Barley Grains Using QuEChERS Method and GC-MS/MS.

BACKGROUND: Cereal grains are an important for the nutrition of both humans and animals, and contribute to the nutrition cycle in different ways. Chemical contaminants are important to be monitored in food due to their direct effects on human health. OBJECTIVE: This work aimed to monitor some of the hazardous chemical contaminants i.e., organochlorines (OCs), pyrethroids, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in wheat and barley grains of European origin during 2019. METHOD: Samples were collected consecutively during the season and the QuEChERS technique (quick, easy, cheap, effective, rugged, and safe) followed by GC-tandem mass spectrometry (GC-MS/MS) analysis was used in the extraction and cleaning up for all analyzed compounds. The method was verified, and a recovery study was performed at two spiking levels: 0.01 and 0.05 µg/g. RSD(%), LOD, and LOQ were calculated. Recovery ranged from 78.70-104.00% for all compounds at both levels at RSD 2.16-11.76%. Fat, moisture, protein, and specific weight contents of both grains of all studied origins were also recorded. RESULTS: Results revealed that all detected pesticides were lower than the estimated maximum residue limits (MRLs). Few congeners of PCBs and PAHs were detected in the most of origins with tiny amounts but no estimated MRLs for it in cereal grains to be compared. CONCLUSIONS: None of the analyzed OCs were detected except endosulfan-I which was detected in some wheat samples from Ukraine and Poland, and some barley samples from Latvia, but still lower than the MRL. HIGHLIGHTS: None of the OCs, highly toxic PCBs or the carcinogenic PAH benzo[a]pyrene were detected in any analyzed samples.

Determination of Heavy Metals in Wheat and Barley Grains Using ICP-MS/MS.

Wheat and barley grains are two of the most important nutritional grains for humans and animals and they play an essential role in the nutritional cycle by different ratios according to people's nutritional habits. This work aimed to monitor ten of the most important heavy metals in some European-origin wheat and barley grains during the season of 2018. The measured elements, Al, As, Cd, Co, Cr, Hg, Mo, Ni, Pb, and V, are of importance ecologically and biologically and may be involved in many health disorders affecting the human body. Moisture, protein, and specific grain weights were checked. Samples were digested using microwave acid digestion and the elements measured with ICP-MS/MS in He mode to increase sensitivity, lower the background, and avoid interference. Method validation and verification were carried out through spiking at two levels (2.0 and 10 ppb), then RSD, LOD, and LOQ were calculated. Recoveries were >97% for all elements at both levels with an RSD of <7.6%. Results revealed that As, Cd, Hg, and Pb were not detected in most wheat and barley samples, whereas Cd was detected in one sample of Ukrainian wheat and two samples of Estonian barley (but in very small traces). Pb was detected in three samples of Polish wheat (in very small traces). Al, Mo, and Ni were detected in some samples of wheat and barley of all origins, whereas other elements were at very low levels considered to be negligible concentrations.