Determination of 73 multi-class pesticides in okra ( Abelmoschus esculentus L.) fruits using LC–MS/MS and GC–MS/MS and estimation of analytical uncertainty of measurement

Highlights

• •

  LC-MS/MS and GC–MS/MS method validated for analysis of 73 pesticides in Okra fruits.

• •

  Recovery at 3 different spiking levels were found within 70–120 % with 15 % of RSD.

• •

  LOQ was 10 µgkg ⁻¹ for all the pesticides which is below the MRLs of FAASI and EU.

• •

  Measurement Uncertainty value at 50 µgkg ⁻¹ were in the range of 1.81 to 12.91 µgkg ⁻¹.

• •

  Method can be used detect the pesticide residues in okra samples at trace level.

Abstract

This study developed a method to simultaneously determine 73 multi-class pesticides in okra fruit using LC-MS/MS and GC–MS/MS. The sample was extracted with acetonitrile and subsequent clean-up through dispersive-SPE method. The quantification level of the technique was 0.01 µg g ⁻¹ and compliance to the MRLs fixed by the regulatory bodies like EU and FSSAI. The recovery at 10, 50, and 100 µg kg ⁻¹ spiked levels; intra and inter-day precision at 50 µg kg ⁻¹ were found within 70–120% with RSD less than 15% with LC-MS/MS and GC–MS/MS. Measurement uncertainty was in the range of 1.81 to 12.91 µg kg ⁻¹ estimated at 50 µg kg ⁻¹. The matrix effects were slightly higher for LC than GC-compatible pesticides. Risk assessment for pesticides detected in the field and market samples found no hazardous to the consumers except profenofos. The proposed method is highly sensitive, reproducible for the complex matrix like okra, and meets the regulatory standards.