Dissipation kinetics, risk assessment, and waiting period of spiromesifen on chili fruits using gas chromatography-electron capture detector.

A supervised field trial was designed in Rajasthan Agricultural Research Institute, Durgapura, Jaipur, Rajasthan, to assess the dissipation and persistence of spiromesifen in chili fruits. Spiromesifen (22.9% suspension concentrate) was sprayed two times at an interval of 10 days at the recommended dose (96 g. a.i. ha-1 ) and double the recommended dose (192 g. a.i. ha-1 ) with four replications. Sampling was done according to the planned interval of days after the second spray. Extraction and cleanup were performed using the modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method and the spiromesifen residue was analyzed by GC-electron capture detector and confirmation performed using GC-MS. The average initial deposit of spiromesifen was 1.207 mg kg-1 and 1.948 mg kg-1 at the recommended and double the recommended dose, respectively. The half-life values of spiromesifen ranged between 2.7 and 3.2 days at the recommended and double the recommended dose. The safe waiting period was calculated for the respective doses and it was concluded that an average of 7 days is safe for picking. The FSSAI (Food Safety and Standards Authority of India) have set the maximum residue limit of 0.1 mg kg-1 for spiromesifen in green chili. The theoretical maximum residue contribution value of spiromesifen was lower than the maximum permissible intake at both the applications on the 0th day. Hence, there will be no adverse effects on human health after consumption of green chilies.

Dissipation kinetics and risk assessment of iprovalicarb + propineb fungicide in tomato under different agroclimates.

Multi-location supervised field trials in India were conducted with a combination pesticide formulation (iprovalicarb 5.5% + propineb 61.25%, 66.75% WP) in tomato to study dissipation behavior at single (iprovalicarb 137.5 g a.i. ha-1 + propineb 1531.25 g a.i. ha-1) and double (iprovalicarb 275 g a.i. ha-1 + propineb 3062.5 g a.i. ha-1) dose. The samples were processed using a modified QuEChERS method for iprovalicarb and acid hydrolysis followed by carbon disulfide estimation for propineb and confirmation of their respective residues by LC-MS/MS and GC-MS. Both the fungicides in tomato fruits obey first-order kinetics irrespective of location and doses. Half-life (t1/2) values at all the four locations ranged from 1.08 to 4.67 days for iprovalicarb and 3.36 to 11.41 days for propineb in tomato. The Food Safety and Standards Authority of India (FSSAI) has set MRL of 1 mg kg-1 for propineb, but no MRL is yet fixed for iprovalicarb. Using OECD MRL calculator, the calculated MRL for iprovalicarb and propineb was found to be 2 and 4 mg kg-1, respectively. The hazard quotient (HQ) < 1, theoretical maximum daily intake (TMDI) < acceptable daily intake (ADI), TMDI < maximum permissible intake (MPI), percent acute hazard index (% aHI) ≤ 1, and percent chronic hazard index (% cHI) < 1 for both the fungicides indicated that the combination formulation will not pose any dietary risk and thus considered safe for human health.

Dissipation kinetics and consumer risk assessment of novaluron + lambda-cyhalothrin co-formulation in cabbage.

Cabbage, one of the most popular vegetables in the world is infested by several insect-pests and diseases. Novaluron, a chitin synthesis inhibitor and lambda-cyhalothrin, a synthetic pyrethroid group insecticide are used to manage insect-pests on cabbage. The dissipation kinetics and risk assessment of combination formulation (novaluron 9.45% + lambda-cyhalothrin 1.9%) with different modes of action has not yet been investigated in cabbage. Multi-location supervised field trials were therefore, conducted in different agro-climatic regions of India for safety evaluation of the combination product. The co-formulation at the recommended (novaluron 750 g a.i. ha-1 + lambda-cyhalothrin 750 g a.i. ha-1) and double the recommended (novaluron 1500 g a.i. ha-1 + lambda-cyhalothrin 1500 g a.i. ha-1) dose was sprayed on the cabbage crop. The samples were extracted and cleaned up using a modified QuEChERS method, and the residues analyzed by GC-ECD and GC-MS. The half-life (t1/2) varied between 1.77 and 2.51 and 2.00-3.38 days for novaluron and 1.36-2.24 and 1.69-3.82 days for lambda-cyhalothrin in cabbage at respective doses. The Food Safety and Standards Authority of India (FSSAI) has set the MRL of 0.7 mg kg-1 for novaluron at PHI of 5 days, and no MRL is set for lambda-cyhalothrin in cabbage. On the basis of OECD MRL calculator, the MRLs of 0.6 and 1.5 mg kg-1 for novaluron and lambda-cyhalothrin, respectively were calculated at the respective doses at PHI of 3 days. Hazard quotient (HQ) <1, theoretical maximum daily intake (TMDI) < acceptable daily intake (ADI) and < maximum permissible intake (MPI), percent acute hazard index (% aHI) <1, and percent chronic hazard index (% cHI) <1 for both novaluron and lambda-cyhalothrin suggested that the combination formulation is safe and will not pose any dietary risk to the consumers. The study will be helpful to conduct risk assessment of other pesticides/combination pesticides on food crops on which their MRLs have not yet been fixed.