• Journal of Food Hygiene and Safety
• /
• v.38 no.3
• /
• pp.152-157
• /
• 2023

This study was aimed to investigate pesticides residue levels in nuts and seeds distributed in Gyeonggi-do. We investigated nuts and seeds in 131 products, which is pumpkin seeds (n=17), sunflower (n=12), sesame (n=23), perilla (n=11), peanut (n=18), almond (n=8), chestnut (n=6), walnut (n=14), pine nut (n=3), pecan (n=4), macadamia (n=3), brazil nut (n=5), cashew nut (n=4) and ginkgo nut (n=3). As a result of evaluating 339 pesticide residues, eight out of 131 samples were detected at the range of 0.01-0.07 mg/kg. Additionally, 7 out of 8 detected samples exceeded MRLs (Maximum Residue Limits) and 85% of them were imported. Pyraclostrobin applied on the positive list system (PLS) was detected in five Chinese pumpkin seeds samples, and the range was 0.02-0.04 mg/kg. In Indian and Korean sesame seeds, pendimethalin, boscalid, and bifenthrin were detected at 0.04, 0.05, and 0.06 mg/kg, respectively. The ratio of estimated daily intake (EDI) to acceptable daily intake (ADI) was 0.002-0.372%, indicating that the risk level was safe.

• The Korean Journal of Pesticide Science
• /
• v.16 no.2
• /
• pp.121-130
• /
• 2012

In analyzing pesticide residue, LLE (liquid liquid extraction) is generally applied as one of the existing methods, but needed quite a lot of organic solvents and analytical apparatuses for the sample pre-treatment. In addition to its long analysis time and complex analytical processes, it is required to develop a more rapid and efficient method at present. In order to establish an economic and simple pesticide residue analytical method, this study carried out a comparative experiment on the existing analytical method with a new sample pre-treatment method named QuEChERS (quick, easy, cheap, effective, rugged and safe), which extracts and refines pesticide components by directly adding solid powder into the sample. Both the two analytical methods showed favorable values of correlation coefficient ($R^2$ > 0.99) of calibration curves. In terms of the detection limit (identification limit), imidacloprid showed 0.02 mg/kg, while the rest of pesticides showed a level around 0.05 mg/kg. The results of this experiment revealed that the recovery of LLE was 92.8-100.9% and the RSD was below 2.5%. On the other hand, the recovery of QuEChERS was 92.2-101.6% and RSD was below 1.9%. As a result of comparing the amount of pesticide residue by the time between the two analytical methods by using Paired t-Test, there was no significant difference between the two analytical methods as the p-value ranged from 0.3148-0.9890. Considering the results of the two methods, the QuEChERS method had similar recovery, compared to the analytical method using the existing LLE, and the analytical time was shortened by about one fourth of that of the existing method. Moreover, since it excludes the use of harmful organic solvents like dichloromethane during the process of extraction, thus leading to protecting experimenters health and remarkably reducing the amount of disused solvents, it is judged as an echo-friendly and economic analytical method.

• Korean Journal of Environmental Agriculture
• /
• v.25 no.3
• /
• pp.217-227
• /
• 2006

Micronutrient status in soils and crops of plastic film house and their relationship were investigated. Total 203 plastic film houses were selected (red pepper, 66; cucumber, 63; tomato, 74) in Yeongnam region and soil and leaf samples were collected. Hot-water extractable B and 0.1 N HCl extractable Cu, Zn, Fe, and Mn in soil samples and total micronutrients in leaf samples were analyzed. Contents Zn, Fe, and Mn in most of the investigated soils were higher than the upper limits of optimum level for general crop cultivation. Contents of Cu in most soils of cucumber and tomato cultivation were higher than the upper limit of optimum level, but Cu contents in about 30% of red pepper cultivation soils were below the sufficient level. Contents of B in most soils of cucumber and tomato were above the sufficient level but in 48% of red pepper cultivation soils B were found to be deficient. Micronutrient contents in leaf of investigated crops were much variable. Contents of B, Fe, and Mn were mostly within the sufficient levels, while in 71% of red pepper samples Cu was under deficient level and in 44% of cucumber samples Cu contents were higher than the upper limit of sufficient level. Contents of Zn in red pepper and cucumber samples were mostly within the sufficient level but in 62% of tomato samples Zn contents were under deficient condition. However, any visible deficiency or toxicity symptoms of micronutrients were not found in the crops. No consistent relationships were found between micronutrient contents in soil and leaf, and this indicates that growth and absorption activity of root and interactions among the nutrients in soil might be important factors in overall micronutrient uptake of crops. For best management of micronutrients in plastic film house, much attention should be focused on the management of soil and plant characteristics which control the micronutrient uptake of crops.