Pre-harvest Residue Limit Research Articles

Dissipation characteristics of spirotetramat and its metabolites in two phenotypically different Korean vegetables under greenhouse conditions

This study involved analysis and method validation of spirotetramat applied to two phenotypically different Korean vegetables (e.g. Korean cabbage and shallots) to determine the safe pre-harvest residue limit (PHRL) and comparative dissipation patterns. Two steps of the investigation involved greenhouse monitoring during crop cultivation followed by LC-MS/MS analysis. Commercial spirotetramat was sprayed twice with seven-day intervals according to the spray schedule (0, 3, 7, 10, 14, and 21 days before harvest) at the dose recommended by the Ministry of Food and Drug Safety (MFDS), Korea. During the validation of the analytical method, good linearity, specificity, and acceptable recoveries (82%–114% for Korean cabbage and 82%–111% for shallot) were established for spirotetramat and its four metabolites. The calculated biological half-life derived from the first-order reaction (t1/2) of spirotetramat was 4.8 days for Korean cabbage and 4.0 days for shallot, respectively. The safe PHRL for Korean cabbage was suggested at 7 days, due to permissible spirotetramat concentration in terms of an acceptable MRL. The findings of the study will be used as the analytical reference point for developing spirotetramat safety guidelines for use in the vegetables investigated.

애호박 중 살충제 buprofezin 및 pyridaben의 생산단계 잔류허용기준 설정

애호박 중 살충제 buprofezin 및 pyridaben의 생산단계 잔류허용기준 설정

Improved dissipation kinetic model to estimate permissible pre-harvest residue levels of pesticides in apples

Prediction of residual concentrations of applied pesticides during the pre-harvest period may be required to ensure the safety of agricultural products. In this study, time-dependent dissipation trends of carbaryl (CB), kresoxim-methyl (KM), flubendiamide (FB), flufenoxuron (FN), bitertanol (BT), and chlorantraniliprole (CN) applied to apples at recommended and threefold greater doses were modeled to estimate pre-harvest residue limit concentrations (CPHRL) indicating permissible pesticide concentrations during the pre-harvest period. Double-exponential (DE) model results best fit the dissipation trends of all tested pesticides (correlation coefficients of 0.91-0.99) compared to zero-, first-, and second-order models. Among the pesticides examined, CB half-lives in apples of 2.9 and 6.6days were the shortest, while those of FN (21.1-32.7days) were the longest. The CPHRL values for each pesticide in apples were estimated with DE model parameter values and could be used to determine harvest dates for safe apples with pesticide concentrations below their maximum residue limits. Application of the DE model for CPHRL calculation provides more accurate information for farmers to produce agricultural products safe from pesticide residues.

Dissipation kinetics, pre-harvest residue limits, and dietary risk assessment of the systemic fungicide metalaxyl in Swiss chard grown under greenhouse conditions

The residual behavior of the systemic fungicide, metalaxyl, in Swiss chard cultivated at two different locations under greenhouse conditions was investigated using high-performance liquid chromatography coupled with an ultraviolet detector (HPLC-UVD). Samples were randomly collected over 14 days and extracted using acetonitrile, partitioned using solid sodium chloride, and a solid-phase extraction (SPE) NH2 cartridge was used for cleanup. The linearity over a concentration range 0.05–50 mg/L was excellent with a coefficient of determination (R2) of 0.9997. The recovery rate ranged from 77.05 to 88.92% with relative standard deviations (RSDs) ≤ 10.74, and the limits of detection (LOD) and quantification (LOQ) were 0.0033 and 0.01 mg/kg, respectively. The initial (2 h after application) deposits were 4.69 and 5.90 mg/kg for sites 1 and 2, respectively, which increased to 4.95 and 6.57 mg/kg, respectively, one day post-application, owing to the systemic properties of the fungicide. The dissipation half-life was 5.3 and 6.0 days for sites 1 and 2, respectively. The pre-harvest residue limit (PHRL) suggested that if 55.38 and 47.23 mg/kg was applied 10 days before harvest or 33.28 and 30.73 mg/kg was applied 5 days before harvest (for sites 1 and 2, respectively) then the concentration will fall below the maximum residue limit (MRL = 20.0 mg/kg) at the time of harvest. The dietary risk assessment, estimated as hazard quotient (RQ%), indicate that metalaxyl can be safely used in/on Swiss chard, with no hazardous effects expected for consumers.

Chromatographic determination, decline dynamic and risk assessment of sulfoxaflor in Asian pear and oriental melon.

The dissipation pattern of sulfoxaflor in Asian pear cultivated in an open field conditions and in oriental melon grown under plastic house conditions was each studied in two different locations. Residues in field-treated samples were determined using liquid chromatography coupled with an ultraviolet detector and confirmed by liquid chromatography-tandem mass spectrometry. A calibration curve for sulfoxaflor was linear over the concentration range 0.1-5.0 mg/L, with a coefficient of determination of 0.9999. The limits of detection and quantification (LOQ) were 0.007 and 0.02 mg/kg, respectively. Recoveries at three fortification levels (LOQ, 10 × LOQ and maximum residue limit) ranged from 70.5 to 86.2%, with a relative standard deviation ≤5.8%. The dissipation half-lives were 10.8 and 7.9 days in pear and 5.4 and 5.9 days in oriental melon, at sites 1 and 2, respectively. Based on a pre-harvest residue limit curve, it was predicted that, if the residues at 10 days before harvest in Asian pear are <0.54/0.61 mg/kg and those in oriental melon are <1.43/1.26 mg/kg, then the residue level will be below the maximum residue limit at harvest. Risk assessment at zero days showed a percentage acceptable daily intake of 10.80% in Asian pear and 1.77 and 1.55% in oriental melon, for sites 1 and 2, respectively. These values indicate that the fruits are safe for consumption.

Dissipation pattern and risk quotients assessment of amisulbrom in Korean melon cultivated in plastic house conditions.

Amisulbrom formulated as suspension concentrate was applied at the rate recommended for Korean melon to determine the dissipation pattern (at two different sites), the pre-harvest residue limit (PHRL), and risk assessments. Samples collected over 10days were extracted using liquid-liquid extraction (LLE) and cleaned up with solid-phase extraction (SPE) Florisil cartridge. Residual concentrations were determined using liquid chromatography-ultraviolet detector (LC-UVD) and confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The standard showed good instrument response linearity with a correlation coefficient (R 2)=0.9999, and the recovery ranged from 87.5 to 93.7%. The dissipation half-life calculated from two different sites were found to be 7.0 and 8.8days for sites 1 and 2, respectively. A PHRL graph constructed from the data indicated that if the residue levels were less than 0.55-0.59mg/kg 3days before harvest or less than 0.61-0.74mg/kg 7days before harvest, then they would be lower than the maximum residue limits (MRLs) at harvest. Risk assessments showed that the risk quotient (RQ) was 4.39-3.47% at 0day, declined to 1.53-1.63% at 10days. Therefore, the current data indicate that the amisulbrom can be applied safely to Korean melon; hence, it is unlikely to induce adverse health effects in consumers.

생산단계 잔류허용기준 설정을 위한 딸기 중 bistrifluron과 chlorantraniliprole의 잔류 특성 연구

생산단계 잔류허용기준 설정을 위한 딸기 중 bistrifluron과 chlorantraniliprole의 잔류 특성 연구

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.

The disappearance rate and risk assessment of thiacloprid residues in Asian pear using liquid chromatography confirmed with tandem mass spectrometry.

This study was undertaken to quantify the residue levels and propose the dissipation kinetics of thiacloprid formulated as suspension concentrate in field-incurred Asian pears grown under two different open-field conditions. Samples were extracted with 20% distilled water in acetonitrile; partitioned with brine water and dichloromethane; and purified with a Florisil solid phase extraction cartridge. The analyte was identified with an LC ultraviolet detector, and field-incurred samples were confirmed using LC-MS/MS. The calibration curve was linear over the range 0.05-5.0 mg/L with a satisfactory coefficient of determination (R2 = 0.9994). The limits of detection and limits of quantification (LOQ) were 0.003 and 0.01 mg/kg, respectively. The recovery rate fortified to blank samples at LOQ, 10× LOQ, and the maximum residue limit (MRL) were between 73.7 and 86.2% with relative standard deviation ≤9.0%. The residual concentrations at both sites were considerably lower than the MRL (0.7 mg/kg) set by the Korean Ministry of Food Drug Safety, with biological half-lives of 5.0 and 7.4 days, for sites 1 and 2, respectively. From the pre-harvest residue limit curve, it was predicted that if the residues were <1.13 or 1.40 mg/kg 10 days before harvest, the residue level would be lower than the MRL during harvest. Risk assessment on day 0 showed an acceptable daily intake (%) of 13.0% and 11.0% for sites 1 and site 2, respectively, which indicates that the residual amounts are not hazardous to the Korean population.

Dissipation Pattern of a Fungicide Mandipropamid in Korean Cabbage at Different Harvest Times under Greenhouse Conditions

본 연구는 엇갈이배추 재배기간 중 mandelamide계 살균제인 mandipropamid를 수확 10일전 1회 살포한 후 각각 0(2시간 이내), 1, 3, 5, 7, 및 10일 후에 엇갈이배추 시료를 채취하여 mandipropamid 잔류량을 분석, 통계학적 생물학적 반감기를 산출하여 생산단계 농약잔류허용기준(Pre-Harvest Residue Limit; PHRL)을 설정하고자 하였다. Mandipropamid의 평균 회수율은 0.4 및 2.0mg·kg-1의 두 수준에서 각각 88.2 ± 3.2% 와 92.2 ± 2.0%이었으며, 분석정량한계는 0.04mg·kg-1이었다. Mandipropamid를 기준량으로 1회 살포 시 엇갈이배추 중의 생물학적 반감기는 포장 1 및 2에서 각각 3.9일과 4.0일 이었고, 생체중 증가가 mandipropamid의 잔류량 감소에 상당한 영향을 나타내었다. 잔류감소 회귀식을 이용한m andipropamid의 생산단계 잔류허용기준은 수확 10일전의 경우 11.07-12.19mg·kg-1 수준, 수확 5일전의 경우 5.76-6.05mg·kg-1 수준인 것이 바람직한 것으로 판단 되었다.

Analysis of mandipropamid residual levels through systematic method optimization against the matrix complexity of sesame leaves using HPLC/UVD.

An analytical method was developed to detect mandipropamid residues in sesame leaves using high-performance liquid chromatography-ultraviolet detection. Samples were extracted with acetonitrile and were prepurified using a solid-phase extraction (SPE) cartridge with an additional dispersive-SPE (d-SPE) sorbent application. The method was validated using an external calibration curve prepared using pure solvent. The linearity was excellent with determination coefficient = 1. The limits of detection and quantification were 0.003 and 0.01 mg/kg, respectively. Recoveries at three spiking levels - 0.1, 0.5, and 1.0 mg/kg - were in the range 80.3-90.7% with relative standard deviations <2%. This method was applied to field-treated samples collected from two different areas, Gwangju and Muan, in the Republic of Korea and the half-lives were similar, 5.10 and 5.41 days, respectively. The pre-harvest residue limit was also predicted for both sites. The proposed method is sensitive and able to quantify trace amounts of mandipropamid in leafy vegetables. The combination of SPE and d-SPE effectively removed the matrix components in sesame leaves. Copyright © 2015 John Wiley & Sons, Ltd.

엇갈이배추 재배기간 중 살균제 Amisulbrom의 생산단계 잔류허용기준 설정

엇갈이배추 재배기간 중 살균제 Amisulbrom의 생산단계 잔류허용기준 설정

Dynamic behaviour and residual pattern of thiamethoxam and its metabolite clothianidin in Swiss chard using liquid chromatography–tandem mass spectrometry

A simultaneous method was developed to analyse thiamethoxam and its metabolite clothianidin in Swiss chard using tandem mass spectrometry (in the positive electrospray ionisation mode using multiple reaction monitoring mode) to estimate the dissipation pattern and the pre-harvest residue limit (PHRL). Thiamethoxam (10%, WG) was sprayed on Swiss chard grown in two different areas under greenhouse conditions at the recommended dose rate of 10g/20L water. Samples were collected randomly up to 14days post-application, extracted using quick, easy, cheap, effective, rugged, safe (QuEChERS) acetate-buffered method and purified via a dispersive solid phase extraction (d-SPE) procedure. Matrix matched calibration showed good linearity with determination coefficients (R2)⩾0.998. The limits of detection (LOD) and quantification (LOQ) were 0.007 and 0.02mg/kg. The method was validated in triplicate at two different spiked concentration levels. Good recoveries (n=3) of 87.48–105.61% with relative standard deviations (RSDs)<10 were obtained for both analytes. The rate of disappearance of total thiamethoxam residues in/on Swiss chard was best described by first-order kinetics with half-lives of 6.3 and 4.2days. We predicted from the PHRL curves that if the residues were <19.21 or 26.98mg/kg at 10days before harvest, then total thiamethoxam concentrations would be below the maximum residue limits during harvest.

생산단계 참외 중 Metalaxyl-M 및 Flusilazole의 잔류허용기준 설정연구

The present study was performed to investigate the pre-harvest residue limit (PHRL) of pesticides namely, metalaxyl-M and flusilazole in oriental melon, and to identify the biological half-life and characteristics of their residues. In this study, pesticides were sprayed once as single spray and double spray on oriental melon. The oriental melon samples were collected at 0, 1, 2, 3, 5, 7, 9 and 11 days before harvest and samples were extracted with QuEChERS method. The residues of both the pesticides were quantified using GC/NPD and LC/MS/MS. The limit of detection was found to be 0.02 mg/kg and 0.01 mg/kg and their recoveries were greater than 95% (95.7% ~ 103.2% for metalaxyl-M and 100.2% ~ 106.8% for flusilazole) for both pesticides. The biological half-lives of both metalaxyl-M and flusilazole were 12 days at single and double spray, respectively. The PHRL of metalaxyl-M and flusilazole was found 1.0 mg/kg and 0.3 mg/kg, respectively for 10 days before harvest. The results of the present study shows the residual level of both the pesticides metalaxyl-M and flusilazole in oriental melon were less than their maximum residual limits.

생산단계 비름 중 Emamectin benzoate의 잔류허용기준 설정

Abstract This study was performed to investigate pre-harvest residue limit (PHRL) in amaranth, toestimate biological half-life of emamectin benzoate and identify the characteristics of the residue. Pesticidesof standard and double appplication rate, were sprayed once on amaranth at 0, 1, 2, 3, 5, 7, 10 ,14 daysbefore harvest. Amaranth sample was extracted with acetonitrile and partitioned with dichloromethane, andpesticide residues were determined with LC/MS/MS. The limit of detection of emamectin benzoate was 0.01mg/kg. Recoveries of emamectin benzoate (B 1a , B 1b ) at two fortification levels of 0.1 and 0.5 mg/kg, B 1a were93.3 ± 0.7% and 93.2± 7.7%, B 1b were 106.6 ± 1.9% and 80.5± 6.6%, respectively. The biological half-livesof emamectin benzoate were about 2.0 days at standard application rate and 1.7 days at double applicationrate, respectively. The PHRL of emamectin benzoate were recommended as 0.84 mg/kg for 10 days beforeharvest.Key words Amaranth, Emamectin benzoate, Pesticide residue, Pre-harvest residue limit

Dissipation pattern and pre-harvest residue limit of abamectin in perilla leaves

The pre-harvest residue limit (PHRL) of abamectin (abamectin B1a and B1b) in Perilla frutescens leaves grown under greenhouse conditions were investigated using high-performance liquid chromatography with a fluorescence detector. Samples were extracted with acetonitrile. The extract was purified through a solid phase extraction procedure. Then the purified extract was derivatized with trifluoroacetic anhydride and N-methylimidazole to form a strong stable fluorescent derivative of abamectin. Finally, derivatized abamectins were conveyed to the detector via an Atlantis C18 column, with water and methanol as a mobile phase. Calibration curves were linear over the calibration ranges with coefficients of determinants r (2) ≥ 0.999. The limits of detection and quantification were 0.0033 and 0.01 mg kg(-1) for abamectin B1a and B1b, respectively. Recovery was assessed in a control matrix at two different fortification concentrations, with three replicates for each concentration. Good recoveries were obtained for the target analytes and ranged from 82.11 to 93.03%, with relative standard deviations of less than 8%. The rate of disappearance of total abamectin on perilla leaves for recommended and double the recommended doses was described as first-order kinetics with a half-life of 0.7 days. Using the PHRL curve, we could predict the residue level of total abamectin to be 0.92 mg kg(-1) at 7 days before harvest or 0.26 mg kg(-1) at 4 days before harvest, which would be below the provisional MRL designed by the Korea Food and Drug Administration.

복숭아 중 Methoxyfenozide와 Novaluron의 생산단계 농약잔류허용기준 설정

Abstract Methoxyfenozide and novaluron were sprayed with single and triple treatments separately on peachduring cultivation period. Samples were collected over 14 days, 8 times in total (0, 2, 4, 6, 8, 10, 12, 14 days).Methoxyfenozide and novaluron were extracted with acetone and partitioned with dichloromethane, and analyzed byHPLC/DAD. Method Quantitation Limit (MQL) were both 0.005 mg/kg, average recoveries of methoxyfenozide attwo fortification levels of 0.05 and 0.25 mg/kg were determined 92.7±2.9% and 102.8±3.1%, and novaluron were98.2±4.8% and 96.7±9.0%, respectively. The biological half-life of methoxyfenozide was about 4.41 days at singletreatment, and 4.24 days at triple treatments. The biological half-life of novaluron was about 14.81 days at singletreatment, and 14.50 days at triple treatments. Dissipation of pesticides on peach was influenced by growth dilutioneffect. In case of application of methoxyfenozide and novaluron following guidelines on safe use of pesticides, thefinal residue level was predicted to be lower than Maximum Residue Limit (MRL). Key words Biological half-life, Methoxyfenozide, Novaluron, Peach, Pre-Harvest Residue Limit (PHRL)

파프리카 재배기간 중 담배나방 방제에 사용되는 살충제의 잔류특성

BACKGROUND: This study was carried out to investigate the residual characteristics of insecticides used for Oriental Tobacco Budworm control and to establish the recommended pre-harvest residue limit leading to contribution in safety of paprika production. METHODS AND RESULTS: The recommended Pre-Harvest Residue Limits (PHRLs) of insecticides during cultivation of paprika were calculated from residue analyses of insecticides in fruits 1, 3, 5, 7, 10, 12, 15, 18 and 21 days after treatment. Paprika samples were extracted with QuEChERS method and cleaned-up with amino propyl SPE cartridge and PSA, and insecticide residues were analyzed either by HPLC/DAD or GLC/ECD. The limits of detection were 0.01 mg/kg for 5 insecticides. Average recoveries were - of 5 insecticides at fortification levels of 0.1 and 0.5 mg/kg. The biological half-lives of the insecticides were 8.5 days for bifenthrin, 11.8 days for chlorantraniliprole, 16.8 days for chlorfenapyr, 7.1 days for lamda-cyhalothrin and 31.3 days for methoxyfenozide at recommended dosage, respectively. CONCLUSION(S): The pre-harvest residue limits for 10 days before harvest were recommended 1.05 mg/kg, 1.41 mg/kg, 0.93 mg/kg, 2.06 mg/kg and 1.08 mg/kg as bifenthrin, chlorantraniliprole, chlorfenapyr, lamda-cyhalothrin and methoxyfenozide, respectively. This study can provide good practical measures to produce safe paprika fruit by prevention of products from exceeding of MRLs at pre-harvest stage.

생산단계 잔류허용 기준 설정을 위한 시설 재배 오이 중 살균제 Amisulbrom의 잔류특성 연구

Abstract The dissipation patterns of amisulbrom in cucumber under a greenhouse condition wasinvestigated to establish biological half-life and pre-harvest residue limit (PHRL). Amisulbrom residue in/oncucumber on the day of application under standard application condition was 0.15 mg kg −1 and decreased to0.06mg kg −1 after 5 days after treatment, so that biological half-life calculated 3.6 day, while initialconcentration of amisulbrom twice application 3 days interval under standard application condition was0.35 mg kg −1 and decreased to 0.09 mg kg −1 after same period and the biological half-life calculated 2.4 day.PHRL was suggested by prediction curve calculated from the decay constant of amisulbrom at standard rate.For example, 1.83 mg kg −1 at 5 days before harvest and 1.03 mg kg −1 at 2 days before harvest were suggested.Key words Amislubrom, Cucumber, Pre-harvest residue limit, Biological half-life 서론 국내 농약 사용량은 1970년에 3,719 M/T 이었으나 2010년 20,413 M/T으로 크게 증가하였으며, 2010년 1,366 품목이 등록되어(MFAFF, 2010) 해충이나 병, 잡초로부터 농작물을 보호하고 수확한 농산물의 저장시 병해충에 의한 손실을 방지하는 등의 용도로 사용되어 농업에 필수 불가결한자재이다(Lee 등, 2010). 또한 농약의 사용을 통하여 식량증산은 물론 농산물의 품질향상과 노동력 절감으로 생산비 감소에 중요한 몫을 담당하고 있다(Lee 등, 2008).그러나 농약은 근본적으로 생물의 생리작용을 저해하여활성을 나타내는 독성을가진화합물이며 작물에 살포된 후농약의 특성이나 환경 조건에 따라 감소하지만 수확물에 잔류되는 경우가 있다(Kim 등, 1997).이러한 농약이 잔류된 농산물 및 식품을 섭취한다면 건강위해성이 발생할 수 있는 가능성이 있기 때문에 농약을 등록할 때에는 대상 작물과 사용시기, 사용량, 그리고 횟수 등에 대한 안전사용기준이 설정되고 있고, 소비자의 안전을위하여 유통되는 농산물에 잔류하는 농약의 양을 법으로 정한 농작물의 농약잔류허용기준[Maximum Residue Limit;MRL]을 설정하여 국제적 수준에서는 물론, 국가차원에서관리감독을 하고 있으며 2012년 2월 현재 427 종의 농약성분에 대해 MRL이 설정되어 있다(KFDA, 2012).농산물 품질관리법(법률 제10022호)에 의하면 농산물 및식품 중 농약 잔류량 검사를 통하여 MRL을 초과한 부적합농산물은 용도변경, 출하연기, 또는 폐기처분 등의 조치를

복숭아의 재배기간 중 살충제 Clothianidin 및 살균제 Fluquinconazole의 생산단계 농약잔류허용기준의 설정

BACKGROUND: It is hard to control the agricultural products exceeding MRL (maximum residue limit) before forwarding. Therefore, NAQS (National Agricultural Products Quality Management Service, South Korea) established PHRL (pre-harvest residue limit) on agricultural products during their cultivation periods. This study was performed to set the PHRLs of peach during cultivation period, and also to estimate biological half-lives for residues of clothianidin and fluquinconazole. METHODS AND RESULTS: Two groups of peach were treated under Korean GAP (Good Agricultural Practices) with application time, single and triple treatments. Sample was collected over 14days (each after 0, 2, 4, 6, 8, 10, 12, 14 days. 8times), and clothianidin and fluquinconazole were analyzed by HPLC/DAD and GC/ECD, respectively. CONCLUSION: The biological half-life of clothianidin in single treatment and triple treatment was 5.2days and 7.0days. That of fluquinconazole was also 3.9days and 4.1days, respectively. The PHRL of peach on 10days before harvest was 1.4 mg/kg in clothianidin and 1.8 mg/kg in fluquinconazole.