Agricultural production spans soil, irrigation water, growing crops, harvested produce, seeds, and processed food ingredients. Each stage carries specific chemical and biological risks. An integrated agriculture testing solution therefore combines several technical modules. Pesticide residues are covered by GC-MS and LC-MS/MS analysis, heavy metals by ICP-MS and AAS, and seed quality and GMO traits by PCR and ELISA. These modules address the safety, authenticity, and compliance dimensions that regulators, traders, and producers evaluate across the supply chain. The sections below define the testing scope and service items, the sampling rules that precede laboratory work, and the operating logic of each instrumental method. Reporting conventions and acceptance criteria close the discussion, so results can be read against maximum residue limits and contaminant thresholds.
testing scope and service items
Service scope in agricultural testing is organized around three tiers of items. The first tier addresses chemical safety. Multi-residue screening covers organochlorine, organophosphorus, pyrethroid, and carbamate pesticides; heavy metal items quantify lead, cadmium, arsenic, mercury, and chromium. The second tier covers biological characteristics, including seed purity, germination percentage, varietal identity, and GMO screening for common transformation events. The third tier evaluates compositional and physical quality — moisture, ash, protein, fat, crude fiber, and mycotoxins where relevant. The service applies to various types of samples: cereal grains, vegetables, fruits, tea, soil, irrigation water, fertilizers, and commercial seed lots. Each service item corresponds to a defined method standard, a stated limit of quantification, and an agreed turnaround period. Clients select items according to the applicable regulatory regime — domestic food safety codes, importing-country requirements, or internal quality targets. The laboratory then assembles the matching test package.
Sample types and collection
Valid results begin with representative specimens, and collection rules differ by matrix. For fresh vegetables and fruits, increments are taken from multiple positions and layers of the lot. The combined sample is reduced by quartering and sealed in clean polyethylene bags. Grain and seed lots are probed at fixed depths and positions, with lot size determining the number of increment points. Soil samples are air-dried, ground, and passed through a standard sieve before weighing. Water samples go into acid-washed containers and are preserved as the method specifies. Perishable matrices travel under chilled conditions, and samples in which residues degrade quickly are analyzed promptly or frozen on arrival. Every container carries a unique label recording origin, batch, date, and sampler identity. This labeling keeps chain-of-custody records intact from field to bench, so the laboratory can accept or reject samples against documented criteria.
Pesticide residue testing — GC-MS and LC-MS/MS
Extraction, cleanup, and instrumental determination form the working sequence of pesticide residue analysis. Homogenized sample portions are extracted with acetonitrile, salted out, and cleaned up by dispersive solid-phase extraction — the QuEChERS approach — before injection. Method choice depends on compound behavior. gas chromatography–mass spectrometry (GC-MS) suits volatile and thermally stable compounds, including organochlorine and pyrethroid residues. Targets are confirmed by retention time together with characteristic ion ratios. liquid chromatography–tandem mass spectrometry (LC-MS/MS) handles polar and thermolabile compounds such as carbamates and many newer molecules. Multiple reaction monitoring gives quantification with strong selectivity in complex plant matrices. Matrix-matched calibration corrects signal suppression, and spiked recovery checks verify that extraction efficiency stays within the acceptance window of the method. Results are reported in mg/kg and compared with the maximum residue limits of the destination market. Any exceedance marks the lot as non-conforming.
Heavy metal detection — ICP-MS and AAS
Closed-vessel digestion is the starting point of heavy metal determination. Weighed portions are decomposed in microwave vessels with nitric acid, sometimes with hydrogen peroxide added, until the matrix dissolves. The clear solution is then diluted to volume for analysis. inductively coupled plasma–mass spectrometry (ICP-MS) measures many elements in one run — lead, cadmium, arsenic, mercury, chromium, copper, and zinc among them — with trace-level detection capability. Internal standards correct instrument drift, and collision cell technology removes polyatomic interferences such as the argon chloride species that overlaps arsenic. Atomic absorption spectroscopy (AAS) offers a simpler route for single-element control: graphite furnace AAS for lead and cadmium, hydride generation for arsenic, and cold vapor AAS for mercury. Control measures include reagent blanks, certified reference material checks, and parallel duplicate determinations. Reported concentrations in mg/kg are judged against food contaminant limits or the soil environmental quality standards applicable to the sample.
Seed and GMO testing — PCR and ELISA
Physiological and molecular items run side by side in seed testing. Germination tests hold counted seeds under controlled temperature, light, and moisture for a prescribed period, after which normal seedlings are counted to compute germination percentage. Moisture is determined by oven drying to constant weight, and varietal purity is assessed against morphological descriptors or protein electrophoresis. For GMO screening, real-time PCR detects transformation-event DNA through screening targets such as common promoter and terminator sequences. Event-specific assays then identify the exact construct, and quantitative PCR states relative GM content as a percentage of total DNA. Enzyme-linked immunosorbent assay (ELISA) works at the protein level. Antibodies capture the expressed novel protein, for example insecticidal or herbicide-tolerance proteins, and the colorimetric signal gives a rapid presence/absence screen at grain intake points. Segregated pre-PCR and post-PCR areas guard against amplicon cross-contamination, and findings are read against the GMO labeling thresholds set by the importing jurisdiction.
Application scenarios and reporting standards
Application scenarios cluster around decision points along the supply chain. Producers test soil and irrigation water before planting to guide fertilization and site selection. Growing operations monitor produce before harvest so that pre-harvest intervals are respected. Traders commission batch testing ahead of export documentation, and processors check incoming raw materials during supplier qualification. Retained duplicate samples permit re-testing when a result is disputed. Reporting follows fixed conventions. Each report identifies the sample, the method standard, the test items, results with units and limits of quantification, and a conformity judgment against the cited criteria. Reports for international trade are commonly issued bilingually and state measurement uncertainty when a result sits close to a regulatory limit. Laboratories working under national accreditation schemes apply documented controls: method validation, instrument calibration, and participation in proficiency testing. These controls remain traceable in the raw data attached to every report file.