Soil Testing

Bhandari, Govinda, et al. Chemosphere 253 (2020): 126594.

Soil contamination by pesticide residues poses significant environmental and health concerns due to the high persistence of pesticides in soil and their potential toxicity to humans.

In this study, we analyzed the concentration and distribution of pesticide residues across three soil depths in 147 samples collected from agricultural land. Approximately 60% of the samples contained pesticide residues, with 25% showing a single residue and 35% containing mixtures of two or more residues, representing 39 different pesticide combinations. Residues were most frequently detected in topsoil layers.

The pesticide concentrations varied from 1.0 μg kg^-1 to 251 μg kg^-1, with an average concentration of 16 μg kg^-1. Organophosphates (OPs), the dominant pesticide group, showed concentrations ranging from 1.23 μg kg^-1 to 239 μg kg^-1, with an average of 23 μg kg^-1. Among the detected contaminants, chlorpyrifos and its degradation product, 3,5,6-trichloro-2-pyridinol (TCP), were the most prevalent. Furthermore, the ionic ratio of DDT and its degradation products indicated ongoing DDT usage in the region.

Fu, Xinglan, et al. Microchemical Journal (2024): 110922.

The presence of available heavy metals in soil poses a significant risk to food security and human health. This study introduces a novel approach using a nanoparticle-modified ion exchange membrane combined with laser-induced breakdown spectroscopy (NMIEM-LIBS) for the sensitive detection of available heavy metals in soil samples.

Gold nanoparticle-modified ion exchange membranes were utilized to efficiently enrich lead (Pb) and cadmium (Cd) ions from soil solutions, followed by detection after separation. This method enables highly sensitive quantitative analysis of available Pb and Cd in soil, achieving detection limits (LoDs) of 2.62 mg/kg and 0.24 mg/kg, respectively.

The method was validated by successfully detecting available Pb and Cd concentrations in three spiked soil samples, yielding recoveries ranging from 87.02% to 115.79% for Pb and 82.45% to 114.81% for Cd. This technique offers a simple, rapid, and sensitive strategy for monitoring available heavy metals in environmental samples, providing a valuable tool for environmental monitoring and risk assessment.

Zhao, Gaosheng, et al. Talanta 282 (2025): 127075.

Soil pollution often arises from the co-presence of heavy metals and organic compounds. However, most current detection methods are limited to analyzing either heavy metals or organic pollutants separately. To address this gap, a novel technique, nanoliter spray-enhanced microwave plasma ionization mass spectrometry (Nano-Spray-EMPI-MS), has been developed for the simultaneous detection of both pollutant types in soil samples.

This study focused on analyzing five heavy metals (Pb, Zn, Cu, Cr, and Ni) alongside three prominent phthalates (PAEs): DEHP, DBP, and DMP. Detection limits for the heavy metals ranged from 0.16 to 0.57 μg L^-1, with quantification limits between 0.53 and 1.88 μg L^-1. For the PAEs, detection and quantification limits ranged from 0.02 to 0.05 μg L^-1 and 0.07 to 0.16 μg L^-1, respectively. Method validation demonstrated recovery rates of 90.9%–105.7% for heavy metals and 89.4%–97.2% for PAEs.

The method was applied to soil samples collected near a lead-acid battery industrial park, revealing varying contamination levels. Lead showed the highest concentration, reaching 862.5 mg kg⁻¹, accompanied by a significantly elevated pollution index. These results underscore the utility of this approach for assessing ecological risks, identifying pollution sources, and developing targeted soil pollution management strategies.