Dissipation and residue of flonicamid in cucumber,apple and soil under field conditions

A method based on QuEChERS-like extraction and UPLC-ESI-MS/MS for the analysis of flonicamid was established. The samples were extracted by acetonitrile–methanol mixture and were purified using PSA. At fortification levels of 0.01, 0.1 and 0.5 mg/kg in cucumber, apple and soil, recoveries ranged from 71.5 to 106.0% with relative standard deviation (RSD) of 2.6–9.9%. The limit of quantification (LOQ) was 0.003 mg/kg for cucumber, apple and soil. This study also investigates the dissipation of flonicamid in cucumber, apple and soil. The dissipation half-lives of flonicamid in cucumber, apple and soil were 3.0–4.9 days, 5.1–6.1 days and 10.3–14.2 days, respectively. The final residues of flonicamid ranged from 0.029 to 0.295 mg/kg in cucumbers, <0.01–0.174 mg/kg in apples and <0.01–0.172 mg/kg in soil, respectively. The observed low residual levels of flonicamid suggest that the cucumber and apple are safe when applied at the recommended dosage.     

Dissipation and residue fate of kresoxim-methyl in tobacco leaves and soil under field conditions

The fate of kresoxim-methyl was studied in a tobacco field ecosystem, and a simple and reliable method was developed for the determination of kresoxim-methyl in soil, green and cured tobacco leaves. Kresoxim-methyl residues were extracted from samples with petroleum ether, and determined by gas chromatography (GC) coupled with an electron capture detector (ECD). Kresoxim-methyl (30% suspension concentration) was applied at 150 g a.i. ha^–1 (the recommended high dosage) and 225 g a.i. ha^–1 (1.5 times the recommended high dosage) in the experimental fields in Huishui and Changsha in China. The limits of detection (LODs) and limits of quantification (LOQs) of kresoxim-methyl in green tobacco leaves, cured tobacco leaves and soil were 0.012 and 0.04 mg kg^–1, 0.12 and 0.4 mg kg^–1, and 0.0015 and 0.005 mg kg^–1, respectively. The average recoveries were 84.5% to 95.7%, 79.8% to 94.3% and 83.3% to 93.8% with relative standard deviations (RSDs) less than 10% in green tobacco leaves at four spiked levels (0.04, 0.2, 2 and 8 mg kg^–1), cured tobacco leaves at three spiked levels (0.4, 1 and 10 mg kg^–1) and soil at three spiked levels (0.005, 0.05 and 0.5 mg kg^–1), respectively. The results showed that the half-lives of kresoxim-methyl in green tobacco leaves and soil were 1.2–5.3 days and 6.7–10.4 days, respectively. At harvest, kresoxim-methyl residues in cured tobacco leaves samples collected 21 days after the last application at the recommended dosage were below 1.0 mg kg^–1. These results could help establish appropriate application frequency and harvest intervals in the use of kresoxim-methyl on tobacco plants.     

Effects of mineral oil spray additives on the distribution and dissipation kinetics of pyraclostrobin and azoxystrobin in banana leaves,fruits, and soil

Using LC–MS/MS, a rapid and sensitive method for the simultaneous determination of pyraclostrobin and azoxystrobin residues in banana matrices (leaf and whole banana) and soil was established. The samples were extracted using acetonitrile and purified through C₁₈ dispersive solid-phase extraction. The average recovery of the analytes in various matrices was in the range of 77.3%–103.9% with an RSD range of 0.9%–9.5%. The initial deposition amounts of pyraclostrobin and azoxystrobin at 2 h in the banana leaves of the mineral oil group were 1.43 and 1.31 times in Guangxi, and 2.10 and 1.81 times in Hainan for the water group, whereas those in the soil of the water group were 3.45 and 3.03 times in Guangxi, and 2.14 and 3.48 times in Hainan for the mineral oil group. The half-lives in the leaves and soil of the mineral oil group were not remarkably different from those of the water group. The terminal residue of the analytes on the whole banana was <0.02 mg/kg at 14 days after application from the two sites. The results of this work may indicate and promote the safety of using pyraclostrobin and azoxystrobin in banana production, especially with mineral oil spray adjuvants.     

Persistence of trifloxystrobin and tebuconazole in banana tissues and soil under the semi-arid climatic conditions of Karnataka,India

Trifloxystrobin and tebuconazole are used for control of Sigatoka leaf spot disease of banana. This study was conducted to evaluate residue persistence of the fungicides in/on banana fruit, other edible parts and soil after spray application of the combination formulation, Nativo 75 WG, at the standard dose, 87.5 + 175 and double dose, 175 + 350 g a.i. ha^?1. The fungicides were extracted from banana and soil with acetone, partitioned into dichloromethane and cleaned-up using activated charcoal for trifloxystrobin and primary/secondary amine (PSA) for tebuconazole samples. The limit of quantification of the method was 0.05 mg kg^?1 for both fungicides. Initial residues of trifloxystrobin were 0.444 and 0.552 mg kg^?1 in/on banana with peel (whole fruit), which reached <0.05 and 0.065 mg kg^?1 after 30 days from treatment at the standard and double doses, respectively. Tebuconazole residues were 0.636 and 960 mg kg^?1 initially and reduced to 0.066 and 0.101 mg kg^?1 after 30 days. Trifloxystrobin and tebuconazole degraded with the half-life of about 11 days. Trifloxystrobin or its metabolite was not detected in the fruit pulp. Tebuconazole being systemic in nature moved to the fruit pulp which was highest on the 3rd day (0.103 and 0.147 mg kg^?1) and remained for 15 days. Matured banana fruit, flower, pseudostem and field soil were free from fungicide residues. For consumption of raw banana 43 days pre-harvest interval (PHI) is required after treatment of the combination formulation. Therefore application of the fungicides towards maturity stage of the fruits may be avoided.     

Analysis of residue dynamics of clofentezine in tangerine and field soil by QuEChERS and HPLC-UV methods

A field experiment was conducted to evaluate clofentezine residue levels and dissipation trend in tangerine and soil for the safe application of clofentezine. A modified QuEChERS-HPLC-UVD method was developed to analyse clofentezine in tangerine and soil. Tangerine samples were homogenised and extracted by acetonitrile and then cleaned up with dispersive solid phase extraction (dSPE) by primary and secondary amine (PSA) and C₁₈. Clofentezine residue was determined by high-performance liquid chromatography (HPLC) with a UV detector (UVD) at the wavelength of 268 nm. The presented method achieved the good linear relationship within the range from 0.05 to 5.0 mg kg^?1 for clofentezine (R² > 0.998). At the fortification levels of 0.05, 0.50 and 1.00 mg kg^?1 in tangerine pulp, tangerine peel and soil, recoveries ranged from 75.9% to 117.7% with relative standard deviations (RSD) less than 8.2%. In the supervised field trials, the half-lives of clofentezine in tangerine and soil were approximately 11.3 and 8.6 days, respectively. At pre-harvest interval of 21 days, the residue of clofentezine in tangerine was below the maximum residue limits (MRL) (0.5 mg kg^?1). Clofentezine (Water Dispersible Granule, 80%) was recommended to be sprayed twice and the recommended dosage ranged from 250 to 375 mg kg^?1.     

Fate of hexaconazole and isoprothiolane in rice,soil and water under field conditions

Residue dissipation of hexaconazole and isoprothiolane in the rice field ecosystem was determined by gas chromatography coupled with electron capture detector. Hexaconazole and isoprothiolane (33% microemulsion) were applied at two dosages, 396 g a.i. ha^–1 (the recommended dosage) and 594 g a.i. ha^–1 (1.5 times the recommended dosage) in the experimental fields in Guizhou, Hunan and Heilongjiang provinces, China, during 2011–2012. The limits of detection and limits of quantification in brown rice were 0.006 and 0.02 mg kg^–1 for hexaconazole, 0.0072 and 0.024 mg kg^–1 for isoprothiolane, respectively, and they were much below the maximum residue limits (MRLs, 0.1 mg kg^–1 for hexaconazole and 1.0 mg kg^–1 for isoprothiolane) set by China. Average recoveries of hexaconazole in water, soil, rice plants and brown rice ranged from 77.3% to 93.8% and for isoprothiolane ranged from 78.1% to 99.9% with relative standard deviations < 10%. The results showed that during harvest, the terminal residue levels of hexaconazole and isoprothiolane in brown rice samples were well below the MRLs of China following the interval of 7 days after last application. Therefore, a dosage of 396 g a.i. ha^–1 was recommended, which could be considered as safe to human beings.     

Dissipation dynamics and final residues of flutriafol in tobacco and soil using ultrasound-assisted extraction before liquid chromatography/tandem mass spectrometry

The dissipation dynamics and final residues of flutriafol on tobacco plant and soil were studied under field conditions. The residues of flutriafol in soil, green tobacco leaves and cured tobacco leaves were extracted by ultrasound-assisted extraction, cleaned up by dispersive solid-phase extraction and detected by liquid chromatography with tandem mass spectrometry. The limits of detection of flutriafol in soil, green tobacco leaves and cured tobacco leaves were 0.006, 0.033 and 0.033 mg·kg^?1, respectively. The limits of quantification of flutriafol in soil, green tobacco leaves and cured tobacco leaves were 0.02, 0.1 and 0.1 mg·kg^?1, respectively. Recoveries were 72.9–102% with relative standard deviations of less than 12% in soil and tobacco matrix. For field experiments, the half-lives of flutriafol in soil and green tobacco leaves were 9.2–11.5 and 9.5–11.1 days, respectively. At harvest, the final residue levels of flutriafol in cured tobacco leaves collected 21 days after one application at the recommended dosage were below 2.0 mg/kg. The maximum residue limit maximum residue limit (MRL) for flutriafol in tobacco has not yet been established in any countries. The data could help the Chinese Government to establish the MRL of flutriafol in tobacco and provide guidance on the proper use of flutriafol.     

Residues and dissipation of chlorothalonil and azoxystrobin in cabbage under field conditions

Chlorothalonil and azoxystrobin, as efficient and broad-spectrum fungicides, are two widely used fungicides to control downy mildew and anthracnose on cabbage. For the safe and rational use of these two pesticides on cabbage, their residues and dissipation were studied under field conditions. The trial results showed that chlorothalonil and azoxystrobin residues were affected by the frequency and dosage of application, and the weather condition post-application. Chlorothalonil and azoxystrobin dissipated rapidly in cabbage with the mean half-live of 1.7 and 0.4 days at three geographical experimental plots in China, respectively. The terminal residues of chlorothalonil and azoxystrobin in cabbage at harvest time were all below the maximum residue limit (MRL, 6 mg kg^?1 for chlorothalonil and 5 mg kg^?1 for azoxystrobin) established by Codex Alimentarius Commission. It suggested that this formulation of chlorothalonil and azoxystrobin (560 g L^?1, SC) may be safer under the recommended dosage. Given that in China no MRL has been set for chlorothalonil and azoxystrobin in cabbage, this study could provide a guidance for establishing MRL, and the safe and rational use of these two pesticides.     

Dissipation dynamics of fenoxaprop-p-ethyl and fenoxaprop acid under Indian rice field conditions

Dissipation dynamics of fenoxaprop-p-ethyl (FPPE) and fenoxaprop acid (FPA) (metabolite) in rice field conditions was investigated for two consecutive seasons. FPPE dissipated rapidly in soil with average half life of 1.42–2.19 days. Dissipation followed first-order kinetics. The method was validated in terms of accuracy, linearity, specificity and precision. Linearity was in the range of 0.005–5 µg mL^?1 with limit of detection as 0.002 and 0.001 µg mL^?1 for fenoxaprop-p-ethyl and fenoxaprop acid, respectively. Quantitation limit in soil, grain, straw and husk were 0.005, 0.008, 0.01 and 0.01 µg g^?1 for fenoxaprop-p-ethyl, and 0.005, 0.01, 0.01 and 0.01 µg g^?1 for fenoxaprop acid, respectively. Recovery in soil, rice grains, straw and husk ranged from 81.60–93.40, 77.85–87.00, 75.20–84.40 and 76.00–87.20% for FPPE and 82.50–88.20, 76.25–83.00, 74.80–83.60 and 75.00–85.40% for FPA, respectively. Below detectable limit of residues of FPPE and metabolite were observed in soil, rice grain, husk and straw samples at harvest. FPPE and FPA were of short persistence under field conditions and residues were below European Union-Maximum Residue Limits in all matrices that would cause adverse effect on environment and human/animal health.     

Persistence and dissipation of fluopicolide and propamocarb on cabbage and soil under semi-arid climatic conditions

Persistence and dissipation of fluopicolide and propamocarb were studied on cabbage and soil as per good agricultural practices over a period of 2 years. A modified QuEChERS analytical method in conjunction with gas chromatography (GC) and GC–mass spectrometry was used for analysis of fluopicolide and its metabolite, 2,6-dichlorobenzamide, and propamocarb in cabbage and soil. The results of the method validation were satisfactory with recoveries within 74.5–100.81% and relative standard deviations 4.8–13.9% (n = 6). The limit of detection (LOD) and limit of quantification (LOQ) of both fluopicolide and 2,6-dichlorobenzamide were 0.003 µg mL^?1 and 0.01 mg kg^?1, respectively. The LOD and LOQ of propamocarb were 0.03 µg mL^?1 and 0.1 mg kg^?1, respectively. During 2013, the initial residue deposits of fluopicolide on cabbage were 0.60 and 1.48 mg kg^?1 from treatments at the standard and double doses of 100 and 200 g a.i. ha^?1 which dissipated with the half-life of 3.4 and 3.7 days. During 2014, the residues were 0.49 and 1.13 mg kg^?1 which dissipated with the half-life of 4.2 and 5.1 days. Propamocarb residues on cabbage were 5.36 and 12.58 mg kg^?1 in the first study (2013) and 4.85 and 10.26 mg kg^?1 in the second study (2014) from treatments at the standard and double doses of 1000 and 2000 g a.i. ha^?1, respectively. The residues dissipated with the half-life of 4–5.5 days. The preharvest interval, the time required for fluopicolide + propamocarb residues to dissipate below the maximum residue limits (notified by EU) at the standard dose, was 11.8 and 14 days during 2013 and 2014. Residue of 2,6-dichlorobenzamide was always <LOQ in cabbage. Residues of fluopicolide, 2,6-dichlorobenzamide and propamocarb were <LOQ in field soil at harvest.     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Dissipation of trinexapac-ethyl and its metabolite in wheat field ecosystems and microbial degradation in soil

To investigate the dissipation rate of trinexapac-ethyl and trinexapac in wheat ecosystem, field and microbial degradation experiments were designed and conducted. A simple and time-efficient analytical method for the determination of trinexapac-ethyl and trinexapac in wheat kernels, plants, straw and soil, using high-performance liquid chromatography–tandem mass spectroscopy (HPLC–MS/MS) was developed. The mean recoveries of trinexapac-ethyl and trinexapac in four matrices at three spiking levels ranged from 72.0% to 108.2%, and the relative standard deviation (RSD) ranged from 2.1% to 11.0%. In supervised field trials, the half-lives of trinexapac-ethyl in the plants were 0.93 and 2.36 d in Shandong and Tianjin, respectively; and those of trinexapac in soil and plants were 1.66 and 1.45 d in Shandong and 2.32 and 1.74 d in Tianjin. In microbial degradation experiment, the results show that the soil microbial communities have effects on their dissipation in the time scale employed.     

Dissipation dynamics of fenamidone and propamocarb hydrochloride in pepper,soil and residue analysis in vegetables by ultra-performance liquid chromatography coupled with tandem mass spectrometry

In this study, a rapid and sensitive method was developed for determining fenamidone and propamocarb hydrochloride residues in vegetables and soil by ultra-performance liquid chromatography-tandem mass spectrometry. The dissipation dynamics of fenamidone and propamocarb hydrochloride in pepper and soil was investigated in Beijing, Henan and Shandong provinces. The target compounds were extracted with methanol and cleaned with dispersive solid phase extraction using primary secondary amine. Two pairs of precursor product ion transitions for fenamidone and propamocarb hydrochloride were measured and evaluated. Average recoveries of fenamidone in potato, tomato, cabbage, pepper and soil at three levels (10, 100 and 1000 μg kg^?1) ranged from 76.91% to 107.31% with relative standard deviations (RSDs) from 2.74% to 10.87% (n = 15). The average recoveries of propamocarb hydrochloride ranged from 74.84% to 97.96% with RSDs from 2.43% to 16.16% (n = 15). The limits of detection (LODs) for fenamidone in each matrix were 0.131–0.291 μg kg^?1, and the limits of quantification (LOQs) were 0.436–0.970 μg kg^?1. The LODs for propamocarb hydrochloride were 0.125–0.633 μg kg^?1, and the LOQs were 0.417–2.11 μg kg^?1. The results also showed that the dissipation of fenamidone and propamocarb hydrochloride in pepper and soil followed first-order kinetics model more than that of bi-exponential models. The half-lives of propamocarb hydrochloride were 6.90–15.78 days in pepper and 13.56–23.02 days in soil. The half-lives of fenamidone were 7.48–11.29 days in pepper and 35.18–42.78 days in soil.     

Dissipation rates of procymidone and azoxystrobin in greenhouse grown lettuce and under cold storage conditions

The dissipation of two fungicides (procymidone and azoxystrobin) was evaluated in greenhouse grown lettuce and under cold storage conditions. Lettuce samples were collected from an experimental greenhouse during a five week period, in which two consecutive applications of these pesticides were performed. Gas chromatography (GC) with electron-capture detection (ECD) was used to study the disappearance of these compounds in lettuce. Confirmation analysis of pesticides was carried out by capillary gas chromatography coupled with mass spectrometry in the selected ion monitoring (SIM) mode. The disappearance rates of these compounds on lettuces in field after two applications were described as pseudo-first-order kinetics with strong correlation between residue concentration and time (r was in all cases higher than 0.983). The half-lives for first and second applications were of 5.31 and 4.65 days for procymidone and 6.23 and 4.87 days for azoxystrobin, respectively. When procymidone and azoxystrobin were applied two times during cultivation, at maximum recommended dose, the residues of both pesticides were below maximum residue limits (MRLs) after the established preharvest intervals. After 21 days under cold and darkness storage conditions, dissipation of procymidone and azoxystrobin was not observed.     

Dissipation kinetics and pre‐harvest residue limit of pyriofenone in oriental melon (Cucumis melo Var. makuwa) grown under regulated climatic conditions

A high‐performance liquid chromatography–ultraviolet detection was used to estimate the disappearance rates as well as the pre‐harvest residue limits of pyriofenone in oriental melon (Cucumis melo var. makuwa ) grown under greenhouse conditions in two different locations (A and B) in Seongju, Republic of Korea. The identity of the compound in standard solution and representative field incurred samples was confirmed using liquid chromatography–tandem mass spectrometry. The method was validated in terms of linearity, limits of detection and quantification, accuracy (expressed as recovery) and precision (expressed as relative standard deviation) for accurate and precise quantitation. Notably, the residual levels of field incurred samples collected over days 0–10 post‐application were below the maximum residue level (0.2 mg/kg) established by the Korean Ministry of Food and Drug Safety. Site A showed lower residue levels and a higher decline rate than site B, which might be attributed to seasonal variation (high temperature) and increased metabolic and enzyme profiling in the mature fruits. The half‐lives were similar, 4.9 and 4.3 days, at sites A and B, respectively. Using the pre‐harvest residue limit, we predicted the residue amounts at 10 and 5 days before harvest, which resulted in concentrations lower than the provisional maximum residue level at harvest time.     

Dissipation Kinetics and Safety Evaluation of Flonicamid in Four Various Types of Crops

The chemical insecticide flonicamid is widely used to control aphids on crops. Differences among crops make the universality of detection methods a particularly important consideration. The aim of this study was to establish a universal, sensitive, accurate and efficient method for the determination of flonicamid residues in peach, cucumber, cabbage and cotton. QuEChERS pretreatment was combined with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A satisfactory recovery rate of 84.3–99.3% was achieved at three spiking levels, and the relative standard deviation (RSD) was 0.41–5.95%. The limit of quantification (LOQ) of flonicamid in the four matrices was 0.01 mg/kg. The residue and dissipation kinetics of flonicamid in four types of crops in various locations were determined by using the optimized method. The results showed that flonicamid had a high dissipation rate in the four different types of crops and a half-life in the different matrices and locations of 2.28–9.74 days. The terminal residue of flonicamid was lower than the maximum residue limit (MRL). The risk quotient (RQ) of flonicamid was 4.4%, which is significantly lower than 100%. This result shows that the dietary risk presented by using flonicamid at the maximum recommended dose is low and acceptable. The comprehensive long-term dietary risk assessment of flonicamid performed in this study provides a reference for the protection of consumer health and safe insecticide use.     

苯醚甲环唑在香蕉和土壤中的残留分析方法研究

建立了苯醚甲环唑在香蕉和土壤中的残留分析方法。样品经乙腈或丙酮、乙酸乙酯提取,中性氧化铝柱净化,GC-ECD检测。方法在0.004~0.4μg/mL范围内有良好的线性关系,香蕉和土壤中苯醚甲环唑最低检测质量分数为0.004 mg/kg。样本中添加量为0.004~1.0 mg/kg时(n=5),平均回收率为81.4%~106.3%,相对标准偏差为1.5%~11%;方法的准确度和精密度均满足农药残留分析的要求。     

Dissipation behavior,residue distribution and dietary risk assessment of chlorfenapyr and clothianidin in leek using RRLC-QqQ-MS/MS technique

Commercial suspension emulsion (SE) of (8% chlorfenapyr + 20% clothianidin), as a pre-registered product in China, was firstly investigated under Chinese open-field conditions. A MWCNTs-based QuEChERS method for simultaneous determination of chlorfenapyr and clothianidin in leek was established and validated through RRLC-QqQ-MS/MS.     

Dissipation and residue behaviour of oryzalin in grape ecosystem using RRLC-QqQ-MS/MS

The dissipation and terminal residues of oryzalin in grape ecosystem under open-field condition were investigated at two different locations, Beijing and Shandong in China. Residues in field-treated samples were determined by a sample method using rapid resolution liquid chromatography triples quadrupole tandem mass spectrometry (RRLC-QqQ-MS/MS). This method showed satisfactory qualitative and quantitative performance. The mean recoveries of oryzalin at different fortification levels (0.01, 0.1 and 1 mg/kg for grape; 0.01, 0.1, 1, 10 and 30 mg/kg for soil) ranged from 88.2% to 98.8%, with the relative standard deviations ≤4.9%. The limits of detection and quantification were, respectively, 0.003 and 0.01 mg/kg. In soil, the dissipation half-lives were about 9 days and the terminal residues ranged from <0.01 to 0.58 mg/kg in both Beijing and Shandong. The concentrations of oryzalin in grapes were lower than 0.01 mg/kg in most of the samples of dissipation study and all the samples of residue study. As far as we know, this is the first study focusing on the dissipation and terminal residue of oryzalin in grape ecosystem, and no maximum residue limits (MRLs) of oryzalin in grapes were recommended by China, Codex Alimentarius Commission or European Union . Therefore, these data not only provide important information about the fate and residues of oryzalin in grape ecosystem, but also could be very useful for the establishment of the MRLs of oryzalin in grapes.     

Dissipation kinetics,residues and risk assessment of propiconazole and azoxystrobin in ginseng and soil

The combinational fungicide suspension (11.7% propiconazole + 7% azoxystrobin), developed by Syngenta Co., Ltd., is very effective for the control of Alternaria black spot on ginseng. A simple and effective method was developed for determining propiconazole and azoxystrobin residues by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The recoveries of propiconazole ranged from 81.0% to 98.0% with relative standard deviations (RSDs) of 1.23–8.46%, while the recoveries of azoxystrobin ranged from 83.2% to 98.8% with RSDs of 3.29–9.50%. For the dissipation kinetics, the combinational fungicide was sprayed with dosage of 225 g a.i.ha^?1 (1.5 times of recommended dosage) in ginseng and soil at two different locations. The dissipation kinetics followed the first-order kinetics with half-lives of 6.66–13.33 days for propiconazole and 4.92–9.12 days for azoxystrobin. Based on the terminal residues data, the preharvest interval (PHI) could be 35 days at recommended dosage in ginseng. The dietary exposure risk was estimated by risk quotient (RQ). The result showed that the RQ value was obviously lower than RQ = 1, indicating that spraying propiconazole and azoxystrobin in ginseng at recommended dosage was safe for human beings.