Tenebrio molitor larvae (mealworm) is an edible insect and is considered a future food. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a novel method for simultaneous analysis of 353 target analytes was developed and validated. Various sample preparation steps including “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) extraction conditions, number of acetonitrile-hexane partitions, and dispersive-solid phase extraction (dSPE) sorbents were compared, and the optimal conditions were determined. In the established method, 5 g of homogenized mealworms was extracted with acetonitrile and treated with QuEChERS EN 15662 salts. The crude extract was subjected to three rounds of acetonitrile-hexane partitioning, and the acetonitrile layer was cleaned with C18 dSPE. The final solution was matrix-matched and injected into LC-MS/MS (2 μL). For target analytes, the limits of quantitation (LOQs) were ≤10 μg/kg, and the correlation coefficient (r2) of calibration was >0.990. In recovery tests, more than 90% of the pesticides showed an excellent recovery range (70–120%) with relative standard deviation (RSD) ≤20%. For more than 94% of pesticides, a negligible matrix effect (within ±20%) was observed. The analytical method was successfully applied and used for the detection of three urea pesticides in 4 of 11 mealworm samples.

In order to use in the classification of minor crop for the mutual application of safe use guideline, it was investigated the residue property of fungicide boscalid and fludioxonil at the same time harvest leafy-vegetables, such as spinach, ulgaribaechu, vitaminchae and cheongkyungchae. After pesticides were applied 2 times with 1 week interval in that day of harvest, 2 days, 5 days and 7 days before harvest, vegetables were harvested, and the residue of pesticides was investigated. Base on the residue in that day of harvest, the deposit of spray solution in vegetables was calculated. The deposit of spray solution of boscalid was 253.9 mL/kg in spinach, 83.0 mL/kg in ulgaribaechu, 97.8 mL/kg in vitaminchae, and 88.3 mL/kg in cheongkyungchae, respectively. In case of fludioxonil, it was calculated 157.6 mL/kg in spinach, 67.6 mL/kg in ulgaribaechu, 64.8 mL/kg in vitaminchae, and 66.6 mL/kg in cheongkyungchae, respectively. When the amount of the deposit of both pesticides was compared in leafy-vegetables, it was the highest in the spinach. On the other hand, it was estimated the predicted dissipation curve of pesticides in leafy-vegetables during cultivation. The half-life of boscalid was 5.9 days in spinach, 7.4 days in ulgaribaechu, 4.6 days in vitaminchae, and 4.3 days in cheongkyungchae, respectively. Also, it was estimated half-life in fludioxonil, it was 3.0 days in spinach, 4.0 days in ulgaribaechu, 3.2 days in vitaminchae, and 3.5 days in cheongkyungchae, respectively. The half-life was the longest in the ulgaribaechu. When both pesticides were compared with the residue property, the deposit of spray solution and half-life of dissipation of boscalid were more than those of fludioxonil.

Fate of acetamiprid and imidacloprid aerially sprayed to control pine wood nematode (Bursaphelenchus xylophilus) were studied in a forest of Haman area. Acetamiprid 20% SL or imidacloprid 20% DC were diluted 100 times and applied two times as rate of 50 L/ha using an aircraft of Bell 206 L helicopter. Average acetamiprid deposits on forest floor ranged from 2 to 4% of standard aerial application rate. Following to the second application, acetamiprid deposits in the pine needle ranged 1.8~8.5 mg/kg and then gradually decreased to 1.2~2.1 mg/kg after 48 days. Deposits on the plant washed off by rainfall and reached to soil surface was ca. 17% of the application rate. All of acetamiprid on the ground resided in the forest floor covering the soil surface, where acetamiprid residues were decreased to a quarter at 48 days after the second application, but they were not detected in soil beneath it. And the only low level of acetamiprid residues, 0.0003 mg/L, was detected in the reservoir nearby the experimental forest on the day of aerial application. The acetamiprid detection was presumably due to spray drift. And average imidacloprid deposits on forest floor ranged from 1 to 3% of standard aerial application rate. Following to the second application, imidacloprid deposits in the pine needle analysed very low concentration of 0.1 mg/kg, but the amount of imidacloprid in wash-off in standard and two-fold treatment were ca. 8% and 4% of the application rate, respectively. Most of imidacloprid on the ground also resided in the forest floor, where imidacloprid residues were decreased to a twentieth at 111 days after the second application, and they were detected below 0.5% of the application rate in sol beneath it. And the low level of imidacloprid, 0.0003~0.0017 mg/L, were detected in the streams in the experimental forest. It was not to the level of contamination concerns.

In order to use in the classification of minor crop for the mutual application of safe use guideline, it was compared a green onion with a scallion on the residue property of insecticide bifenthrin and chlorfenapyr. After pesticides were applied 2 times with 1 week interval in that day of harvest, 3 days, 7 days, 10 days and 14 days before harvest, vegetables were harvested, and the residue of pesticides was investigated. Base on the residue in that day of harvest, the deposit of spray solution in vegetables was calculated. The deposit of spray solution of bifenthrin was 123.0 mL/kg in a green onion, and 74 mL/kg in a scallion. In case of chlorfenapyr, it was calculated 126.5 mL/kg in a green onion, and 70.0 mL/kg in a scallion. When the amount of the deposit of both pesticides was compared a green onion with a scallion, it was higher in a green onion. On the other hand, it was estimated the predicted dissipation curve of pesticides in a green onion and a scallion during cultivation. The dissipation curve of bifenthrin was y = 1.0334 e −0.0602x (R 2 = 0.8606) in a green onion, and y = 0.7693 e −0.1823x (R 2 = 0.9756) in a scallion. In case of chlorfenapyr, it was y = 2.2603 e −0.0519x (R 2 = 0.9043) in a green onion, and y = 1.2940 e −0.1051x (R 2 = 0.9782) in a scallion. The half-life of bifenthrin was 11.51 days in a green onion, and 3.80 days in a scallion, respectively. Also, it was estimated half-life in chlorfenapyr, it was 13.35 days in a green onion, and 6.59 days in a scallion, respectively. The half-life of both pesticides in a green onion was longer than in a scallion. When both vegetables were compared with the residue property, the deposit of spray solution and half-life of dissipation in a green onion were more than those in a scallion.

In this study, we monitored the residues of organophosphate pesticides (OP) in eight fruit vegetables grown in Korea, and assessed risk levels of acute and chronic exposure of OP through the consumption of fruit vegetables. Chlorpyrifos, EPN, methidathion and phosphamidon in eight fruit vegetables were detected in this study. The results of cumulative assessment of national estimated short term intake for acute exposure of OP were due to the following order; eggplant, tomato, squash and cucumber. Total theoretical maximum daily intake calculated at first step of chronic exposure assessment for registered OP in Korea was 76.14%, compared with acceptable daily intake ADI) based on chlorpyrifos. In addition, total national estimated maximum daily intake calculated at second step of chronic exposure assessment was 13.949%, compared with ADI. Third chronic assessment was conducted by probabilistic approach using OP residues detected in eight fruit vegetables and showed that total exposure risk was very low, corresponding to 0.0001% compared to ADI. Based on those finding, the risk of organophosphate pesticides in fruit vegetables was considered quantitatively negligible. In future, further investigation to expand the target should be followed to do more accurate and detailed risk assessment.