Pesticides and Toxic Chemicals Laboratory
About the laboratory
The Pesticides and Toxic Chemicals Laboratory (PTCL) is the technical arm of the Pesticides and Toxic Chemicals Control Board (PTCCB). Established in 2008, PTCL provides essential chemical analysis services to support Guyana’s national chemical management program, while ensuring food safety.
Located at the NAREI Compound, Agriculture Road, Mon Repos, East Coast Demerara, the laboratory is a multi-purpose, ISO 17025:2017 accredited facility with expertise agrochemical formulations, fertilizer analysis, pesticide residue analysis and water quality testing, benefiting farmers, manufacturers, regulators and consumers.
There are two departments within the laboratory:
- Quality Control Unit
- Residue Unit
Quality Control Unit
The Quality Control Unit plays a critical role in ensuring that all formulated pesticides meet the standards set by the Board and align with the technical data submitted for registration. To fulfill this mandate, the unit utilizes advanced analytical instruments, including High-Pressure Liquid Chromatography (HPLC) coupled with a Mass Spectrometer (MS) and a Photodiode Array (PDA) detector. These technologies allow for accurate and reliable analysis of pesticide formulations.
In addition to pesticide testing, the laboratory expanded its services in February 2021 to include the testing of imported fertilizers. Quality assessments focus on determining the macronutrient content of these products, using state-of-the-art instrumentation.
Residue Unit
The Residue Unit is dedicated to ensuring the safety of food commodities in relation to pesticide use. This unit specializes in the analysis of rice grains, fruits, vegetables and surrounding vegetation and water to detect and quantify pesticide residues, ensuring that what reaches the consumers is safe and compliant with national and international standards.
Using validated chromatographic methods from the Association of Official Analytical Chemists (AOAC), the laboratory employs both Gas Chromatography (GC) and High-Pressure Liquid Chromatography (HPLC). These techniques allow for the identification of pesticide compounds based on their unique mass-to-charge ratio and retention time. A mass spectrometer is utilized to accurately quantify all detectable pesticide compounds of interest using its corresponding certified reference material. Together, these two techniques empower staff to effectively analyze many samples for residues.
The Residue Unit also conducts several water quality analysis on a variety of water sources; mineral water, drinking water, groundwater, surface run-offs, aquaculture water, etc. The following parameters are routinely analyzed to assess water quality and ensure safety and compliance: Turbidity, pH, Conductivity, Total Dissolved Solid, Dissolved Oxygen, Elemental Analysis (Mg, Zn, Ca, Fe, Nitrates and Phosphates, etc.).