Thermal Effect on Recovery Levels of Some Selected Organochlorine Pesticides (OCPs) and Triazine Herbicides During Preparatory Analysis

Abstract

Organochlorine pesticides and triazine herbicides are synthetic pesticides widely
used in agriculture all over the world to control pests. They have been linked with
human, environmental and health hazards, from short-term impacts to chronic
impacts. This research work presents a methodology to reduce the time taken to
dry and recover organochlorine pesticides and triazine herbicides samples from 40
hours to 9 hours by proposing the use of oven drying technique over the traditional
air drying method. The results obtained were found to be promising. Recovery
efficiency is an important factor when it relates to analytical methods being
evaluated. The calculated percentage analyte recoveries were in the range of 53-
107% for OCPs and 75-108% for triazines. This showed excellent recovery was
found (>75%) with exception to the low recoveries found in isodrin (53-58%) and
Aldrin (55-61%), although both percentage recovery falls within the acceptable
analysis range (>50%), Isodrin and Aldrin analysis using this method will be
considered qualitative analysis and not quantitative according to International
norm. c-HCH was found to have the highest percentage recovery 100-107% using
this methodology. In conclusion, the use of oven to dry samples of organochlorine
pesticides and triazine herbicides for analysis is an effective method, except for
isodrin and Aldrin. The major advantage of the proposed method of oven-drying
is the short time required for sample preparation (9 hours), the low cost, and ready
availability in any standard laboratory.