Organophosphate Pesticide Residues Research Articles

Organophosphate pesticide residue impact on water quality and changes in macroinvertebrate community in an Afrotropical stream flowing through farmlands.

River Chanchaga has experienced significant agricultural practices around its catchment, which involved the indiscriminate use of pesticides. However, residents of the study area are not well aware of the negative impact of pesticides on water quality and macroinvertebrates. In this study, the first report on the influence of organophosphate pesticide contamination on the abundance of the macroinvertebrate community was provided. Sampling for the determination of organophosphate pesticide residues was carried out during the peak of the two seasons, while macroinvertebrates and physicochemical variables were observed for 6 months. We examined 11 organophosphate pesticide residues using gas chromatography coupled with mass spectrometry, 12 water quality variables, and 625 macroinvertebrate individuals. The concentration of recorded organophosphate pesticide residues ranged from 0.01 to 0.52 μg/L. From the Canonical Correspondence Analysis plot, malathion, chlorine, and paraffin show a positive correlation with Unima sp., Hydrocanthus sp., Chironomus sp., and Potadoma sp. At station 3, depth shows a positive correlation with Biomphalaria sp. and Zyxomma sp., indicating poor water quality as most of these macroinvertebrates are indicators of water pollution. Diuron and carbofuran show a negative correlation with Lestes sp. and Pseudocloeon sp., and these are pollution-sensitive macroinvertebrates. The total mean concentration of organophosphate pesticide residues was above international drinking water standards set by the World Health Organization except for paraffin, chlorpyrifos, and diuron. In conclusion, the observations recorded from this research are useful in managing pesticide applications around the river catchment.

A Review on Extraction and Chromatographic Techniques for Organophosphate Pesticidal Residue Analysis in Paddy and Rice Bran

Organophosphorus pesticides (OPPS) are extensively employed in agricultural techniques and may expose people to them via food intake. We offer an analytical approach for detecting OPPS in paddy, rice grains and or rice bran that combines solid-phase extraction with a high-performance liquid chromatography detector. Acetonitrile extraction was used before SPE–HPLC–MSMS to isolate specific residues, which helped decrease matrix disruptions and identify a broad array of numerous residues in rice grains. Accordingly, ranges of quantitative determination ranged from 0.01mg/kg to more than 1.0 mg/kg, with coefficients extending from 0.995 to more than 0.999. At three stimulating intensities, high recuperation was reported, suggesting excellent precision. The relative SD of all residues confirmed the technique’s accuracy. Using this, various OPPS were quantified, ranging from just below to maximum permissible limits to exceeding the limit. According to a sample study of different rice grain varieties accessible in the international market. This study focuses on the techniques of organophosphate pesticide residue extraction from paddy and rice ban. The study further discusses chromatographic techniques for the same.

Organophosphate, Carbamate and Synthetic Pyrethroid Pesticide Residues in Muscle Tissues of Fish from Loktak Lake, a Ramsar Site in Manipur, India

The muscle tissues of Channa punctatus and Anabas testudineus collected from the Loktak Lake (a Ramsar site) and its three major feeder rivers in Manipur, Northeastern India, were analyzed using high-performance liquid chromatography for the presence of residues of three organophosphorus (malathion, dichlorvos and monocrotophos), one carbamate (carbofuran), and two synthetic pyrethroid (deltamethrin and cypermethrin) pesticides. Residues of all the pesticides except monocrotophos were detected in the fish tissues. Among the five pesticides detected, concentrations of dichlorvos exceeded the maximum residue limit (MRL) prescribed by the Codex Alimentarius for animal tissues such as mammalian offal, eggs and poultry meat. The rest of the compounds were within the MRL for eggs and animal tissues. None of the pesticide residues was detected in the two fish species collected from the control or reference site. The present study indicates that pesticide contamination is emerging as a threat to the water quality and aquatic biodiversity of Loktak Lake, which is a “wetland of international importance” (Ramsar Site) located in a global biodiversity hotspot. The findings of this study also calls for more detailed investigations on the presence of pesticide residues in water, sediments, aquatic macrophytes, planktonic and benthic organisms, and different fish species of this wetland ecosystem.

Highly Sensitive and Rapid Screening Technique for the Detection of Organophosphate Pesticides and Copper Compounds Using Bifunctional Recombinant TrxA-PvCarE1.

Enabling the detection of organophosphate pesticide (OP) residues through enzyme inhibition-based technology is crucial for ensuring food safety and human health. However, the use of acetylcholinesterase, the primary target enzyme for OPs, isolated from animals in practical production poses challenges in terms of sensitivity and batch stability. To address this issue, we identified a highly sensitive and reproducible biorecognition element, TrxA-PvCarE1, derived from red kidney beans and successfully overexpressed it in Escherichia coli. The resulting recombinant TrxA-PvCarE1 exhibited remarkable sensitivity toward 10 OPs, surpassing that of commercial acetylcholinesterase. Additionally, this approach demonstrated the capability to simultaneously detect copper compounds with high sensitivity, expanding the range of pesticides detectable using the traditional enzyme inhibition method. Spiking recovery tests conducted on cowpea and carrot samples verified the suitability of the TrxA-PvCarE1-based technique for real-life sample analysis. In summary, this study highlights a promising comprehensive candidate for the rapid detection of pesticide residues.

Biochemical Response of the Endogeic Earthworm (Balanteodrilus extremus) Exposed to Tropical Soils

This work evaluated the biochemical responses of the endogeic earthworm Balanteodrilus extremus exposed for 14 and 48 days (d) to soils collected from two tropical agricultural systems: maize-sorghum (MS) and soybean-sorghum (SS). A soil without agricultural management (WAM) and the use of pesticides was selected as a reference. The presence of organochlorine (OC) and organophosphate (OP) pesticide residues was quantified in MS and SS soils. Biomarkers of detoxification [glutathione S transferase (GST)], neurotoxicity [acetylcholinesterase (AChE)] and oxidative stress [superoxide dismutase (SOD), catalase (CAT) and lipoperoxidation (LPO)] were evaluated in B. extremus. The concentration of OP pesticide residues was higher in SS than in MS. Activity of AChE in B. extremus exposed to SS soil for 14 d was significantly more inhibited (78%) than in MS soil (68%). B. extremus has been shown to be a good bioindicator of contaminated soils in tropical regions.

Pesticide residue exposure effect on health, growth, and development among children from agricultural area

Nowadays, the exposure to pesticides has become a matter of public health concern. The primary and secondary take-home exposure of pesticides may influence the health of communities. Farmworkers’ families generally live close to agricultural areas, which may increase the risk of residential pesticide exposure. Pesticide exposure affects children more than adults. Environmental quality drives the shifting patterns of children’s major health problems, from infectious to chronic diseases. Children’s developing organs may be exposed to low-dose concentrations of environmentally disruptive pesticides such as organophosphates, organochlorines, carbamates, and pyrethroids. Several groups of pesticide metabolites induce and inhibit growth and development in children. Potential health problems such as chronic respiratory disease, asthma, and wheezing in children were more often reported from agricultural communities than children from rural areas. Children who were in contact with pesticides during both their prenatal development and childhood reported diminished cognitive scores. This can be attributable to the elevated levels of pesticides found in their urine, which have been extensively documented. Diammonium phosphate (DAP) metabolites as one of the organophosphate pesticides (OPPs) residues correlate with high KIM-1 levels in urine, significantly leading to chronic kidney disease. DNA damage may be A potential reported effect in children from agricultural communities. Thus, to ensure children’s health and development, it is necessary to strengthen the impact of pesticide studies on children.

Evaluation of Organophosphates Residue in Stored Cereals from Some Selected Markets in Jalingo, Nigeria

Cereal grains such rice, sorghum, maize and millet among others are the staple foods in large parts of the world, supplying most of the energy and bulk in diets. Pesticide residue analysis in cereals from the various sampling locations for this dissertation revealed the following organophosphate pesticide residue were present in cereals analyzed Dichlorvos, Diazinon, Phorate sulfon, Malathion, Phorate, Chloropyrifos, Methyl Parathion, Profenofos, Ethion, Dimethoate, Phorate Sulfoxide, Phosalone, Edifenfos, Fenitrothion and Chlorofenvinfos. The presence of pesticide residues is detected in the samples of cereals (Rice, Maize, Millet and sorghum) analyzed. This could be as a result of high utilization of various pesticides during plant, cultivation and storage thus leading to the bioaccumulation of this substance in the individual cereals. It indicates high levels of non-carcinogenic risk associated with the life time consumption of cereals produce and sold within this region. Based on findings from this study’s, I hereby make the following recommendations. Regulatory agencies in Nigeria should step up efforts to ensure compliance with the ban on these chemicals. Farmers and other pesticide users also need to be educated on the dangers of using banned products and on the over application of these pesticides. Furthermore, farmers should be educated on the properly usage of these chemical product, during plant, harvest and storage. Also, manufacturers of these chemicals should produce less toxic pesticide using organic materials in other to prevent the health risk associated with chemical pesticide and their residues in food crops and the environment.

Organophosphate pesticide residues in surface water and bilih fish (Mystacoleucus padangensis Blkr.) in Lake Singkarak, West Sumatra

Organophosphate pesticide is a pesticide derivate that is used widely by farmers because it has a high killing power against insects and easily disappears from plants. Organophosphate pesticide residues can accumulate in the environment and also cause acute and chronic poisoning in humans. Singkarak Lake in West Sumatra Province is surrounded by many agricultural and farming areas. One of fisheries resources that can be affected by activities at those areas is Bilih fish (Mystacoleucus padangensis). The study aims to determine the levels of organophosphate pesticide residues in Singkarak Lake’s water and Bilih fish. Seven organophosphate pesticide compounds: Diazinon, Fenitrothion, Methidathion, Malathion, Chlorpyrifos, Parathion, and Profenofos were analyzed. In June 2021, surface water and Bilih fish samples were collected from 10 sampling locations in Singkarak Lake. The organophosphate pesticide in the samples was determined using gas chromatography. The results showed that residues were detected in water samples of four locations (Ombilin, Tikalak, Sumani, and Paninggahan), but not in the other six locations (Batu Taba, Sumpur, Guguak Malalo, Saniang Baka, Muaro Pingai, and Tanjung Mutuih) as well as below 1 ppb. Methidathion, Malathion, Chlorpyrifos, and Parathion were detected in lake water at range 2 to 8 ppb. Except for the Bilih fish sample from Ombilin, the majority of the samples contained organophosphate residues. Diazinon, Fenitrothion, Methidathion, Chlorpyrifos, Parathion, and Profenofos were the organophosphate derivate found in the fish samples. Malathion compound was not found. The organophosphate residue concentration in Bilih fish ranged from 2 to 70 ppb.

Organophosphate Pesticide Residues in Food Products in Kenya and their Chromatographic Detection: A Systematic Review

Organophosphate pesticides are used worldwide to control several pests and meet food demand. These chemicals harm non-target animals and people when misused. Thus, they are a health and environmental concern. The purpose of the systematic review was to synthesise the amount, breadth, and quality of evidence from empirical studies concerning the presence, type, and quantity of OPs in food products in Kenya. A systematic review was done by following the PRISMA protocol. For the identification of studies, the following databases were used: Google Scholar, Web of Science, Scopus, and PubMed. The study focused on peer-reviewed articles published between January 2001 and August 2022. Twelve studies met the inclusion criteria for the scoping review. The main methods used in detecting and quantifying organophosphates in the studies were High-Performance Liquid Chromatography (HPLC) and Gas Chromatography-Mass Spectrometry (GC-MS). Most studies (86.67%) reported significant levels of OPs in food products, exceeding the MRLs and the Acceptable Daily Intake (ADIs) set by the World Health Organization. Six of the studies (50%) reported the presence of OPs in plant products (vegetables, cereals, and fruits), while three (25%) found residues in animal products (milk and meat). The most notable OP compounds detected were chlorpyrifos, acephate, profenofos, diazinon, omethoate, and dimethoate. Most of the food samples in the reviewed studies presented contamination, making them a significant risk to human health due to bioaccumulation. Studies done in Kenya for the last 20 years continue to report high levels of organophosphate residues and their metabolites in food products, both from plant and animal origin. Although the residues are below MLRs in some samples, they can accumulate at higher levels in humans, becoming a severe health risk

Concentration levels and risk assessment of organochlorine and organophosphate pesticide residue in selected cereals and legumes sold in Anambra State, south-eastern Nigeria

Abstract The levels of organochlorine and organophosphate pesticide residues in selected cereal crops (beans, cowpea, millet, maize, sorghum, and rice) purchased from major markets in Anambra, south-eastern Nigeria, were assessed and compared with established MRLs. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used for extraction and clean-up of pesticide residues. Thereafter detection and quantification were done using GC/MS. The result reveals that the analysed grain samples contained some organochlorine pesticides and organophosphates. The organochlorine was most dominant followed by the organophosphates. Organochlorine pesticide residues varied from 0.048 to 0.298 mg/kg in beans, BDL to 0.398 mg/kg in cowpea, 0.018–0.337 mg/kg in maize, 0.023–0.375 mg/kg in millet, 0.058–0.415 mg/kg in sorghum and 0.045–0.442 mg/kg in rice while organophosphate pesticide residue varied from BDL to 0.315 mg/kg in beans, BDL to 0.113 mg/kg in cowpea, BDL to 0.228 mg/kg in maize, BDL to 0.253 mg/kg in millet, BDL to 0.218 mg/kg in sorghum and BDL to 2.1 35 mg/kg in rice. Highest concentration of endosulphan II (0.442 mg/kg) was detected in rice, followed by aldrin (0.415 mg kg−1) in sorghum and endosulphan II (0.40 mg/kg) in sorghum. The pesticide toxicity index (PTI) was above one (1), whereas health index (HI) was less than one (1) and cancer risk were within USEPA reference guideline for crops indicating children will have greater health effect than adults. Hence, strict monitoring and control of pesticide residues in agricultural products is advocated.

Degradation effects on dichlorvos by a biocontrol strain, Trichoderma atroviride T23

Excessive use of organophosphate pesticides (OP), such as dichlorvos, in farming system poses a threat to human health through potential contamination of environment. To date, biodegradation has been prospected most promising approach to eliminate environmental OP residues. Trichoderma species as a biological control microorganism is often exposed to the chemical pesticides applied in environments, so it is necessary to understand the mechanism of degradation of dichlorvos by Trichoderma. In this study, dichlorvos significantly inhibited the growth, sporulation and pigmentation of T. atroviride T23, and the dichlorvos degradation activity of T23 required the initial induction effect of dichlorvos and the culture conditions, including the nutrient and pH values of the medium. Various changed primary and secondary metabolites released from T23 in the presence of dichlorvos were speculated as the energy and antioxidants for the strain itself to tolerate dichlorvos stress. The results showed that T23 could produce a series of enzymes, especially the intracellular enzymes, to degrade dichlorvos. The activities of the intracellular enzyme generated by T23 were differentially changed along time course and especially relied on initial dichlorvos concentration, ammonium sulfate and phosphate added in the medium. In conclusion, some dichlorvos-induced chemical degradation related enzymes of T23 were proved to be involved in the degradation of dichlorvos.

Magnetic Relaxation Switching Immunosensors via a Click Chemistry-Mediated Controllable Aggregation Strategy for Direct Detection of Chlorpyrifos.

Chlorpyrifos (CPF) is the most frequently found organophosphate pesticide residue in solid food samples and can cause increasing public concerns about potential risks to human health. Traditional detection signals of such small molecules are mostly generated by target-mediated indirect conversion, which tends to be detrimental to sensitivity and accuracy. Herein, a novel magnetic relaxation switching detection platform was developed for target-mediated direct and sensitive detection of CPF with a controllable aggregation strategy based on a bioorthogonal ligation reaction between tetrazine (Tz) and trans-cyclooctene (TCO) ligands. Under optimal conditions, this sensor can achieve a detection limit of 37 pg/mL with a broad linear range of 0.1-500 ng/mL in 45 min, which is approximately 51-fold lower than that of the gas chromatography analysis and 13-fold lower than that of the enzyme-linked immunosorbent assay. The proposed click chemistry-mediated controllable aggregation strategy is direct, rapid, and sensitive, indicating great potential for residue screening in food matrices.

Temporal evolution of organochlorine and organophosphate pesticide residues in wells in the Akkar Region (Lebanon).

The Akkar plain is the second largest agricultural area in Lebanon. This region produces huge amount of regular crops such as maize, fruits, and vegetables. In order to protect the crops, farmers use large quantities of many pesticides (including authorized and prohibited molecules) without respecting the recommended doses. In this work, we wanted to study the evolution of OCP and OPP residues at 3-year intervals in water wells in the Akkar region. Twenty OCPs and 8 OPPs were monitored in eight wells in different villages in the plain and mountains of Akkar. Solid phase extraction (SPE) method was used for pesticide extraction, followed by gas chromatography-mass spectrometry (GC-MS) analysis. The results revealed an increasing concentration of OCPs and OPPs in groundwater over the last 3years (between 2017 and 2019-2020). This increase in contamination is due to the uncontrolled and still unregulated (by the authorities) use of pesticides, and also to the introduction of new crops. The concentrations found in groundwater confirm that some banned pesticides are still widely used. The calculation of the theoretical pesticide intake suggests that pesticide concentrations in Akkar represent a greater health risk for the population consuming well water during the rainy season.

Assessment of organophosphate pesticide residues in environmental media of Araromi farm settlement, Osun State, Nigeria.

The aim of the study was to assess the occurrence and distribution of organophosphate compounds residue in soil, surface water, sediment, and banana crops in Araromi farm settlement, Osun State, Nigeria. Organophosphate pesticide residues were determined using a gas chromatography equipped with Flame-Ionization Detection (GC-FID) in 16 soil samples from cocoa and banana farms, 6 water and sediment samples each, and 8 banana samples from 4 farms in the study site. Fourteen organophosphate compounds were detected (acephate, omethoate, dementon-s-methyl, dimethoate, tolcofos-methyl, pirimiphos-methyl, malathion, chlorpyrifos, methidathion, prothiofos, profenofos, ethion, azinphos-methyl and pyrazophos). Tolclofos-methyl, pirimiphos-methyl and prothiofos were detected in all the soil and sediment samples with concentration ranges of 1.9-12.9, 2.25-6.98 and 3.38-9.89 mg/kg respectively in soil and 8.13-9.83, 2.82-25.1 and 3.70-19.5 mg/kg respectively in sediment. Dimethoate, pirimiphos-methyl and prothiofos with concentration ranges, 0.06-0.28, 0.09-0.18 and 0.16-6.11 mg/L respectively were mostly detected in water samples while dimethoate, tolcofos-methyl, malathion, methidathion, prothiofos, ethion and azinphos-methyl compounds were detected in all the banana samples with concentration ranges, 3.40-12.0, 1.82-6.26, 5.73-9.48, 29.7-145, 8.24-20.1, 3.87-9.35 and 3.66-12.2 mg/kg respectively. The organophosphate mean residue concentrations were mostly significantly higher than the Maximum Residue Limits (MRL) at p<0.05. Across the three samples, only pirimiphos-methyl was significantly higher in water samples, omethoate in sediment; acephate, dementon-s-methyl and chlorpyrifos in banana were also not significantly higher at p<0.05. A strong positive significant correlation was observed between the organophosphate compounds in the banana and water samples (R=0.77, p=0.002) at p<0.05. The occurrence of organophosphate compounds in concentrations above MRLs may pose serious environmental and health risks.

Assessment of Neurotoxic Pesticides Residues in Fruits and Vegetables by Bioassay Technique

A study was performed to investigate the status of organophosphate and carbamate pesticide residues present in fruits and vegetables. For this purpose, samples were collected from the local markets of Godawari municipality and Dhangadhisub-metropolitan city of Sudurpaschim province in the Kailali district of Nepal. Samples were analyzed for pesticide residues by the rapid bioassay for pesticide residues (RBPR) technology. The obtained results showed that in fruits the highest inhibition (%) of carbamates(CMs) was present in the banana 29.488%and the highest inhibition (%) of organophosphates(OPs) was present in orange 17.433%. The highest acetylcholinesterase (AChE) inhibition (%) of CMs and OPs pesticides was found to be associated with Sting gourd i.e. 20.574% and 25.357% respectively. The findings point out the urgent need to address the potential risk of exposure to multiple pesticide residues via stringent monitoring programs on daily basis from pesticides present in the diet.

The Assessment of Organophosphate Pesticide Exposure among School Children in Four Regions of Thailand: Analysis of Dialkyl Phosphate Metabolites in Students' Urine and Organophosphate Pesticide Residues in Vegetables for School Lunch.

In Thailand, pesticides containing organophosphates (OP) are frequently applied to crops to suppress insects. School children can be exposed to OPs on a daily basis, from food consumption to breathing and touching pesticides drifted near classrooms. Living in an agricultural area can also be one of the causes. As a result, it is important to monitor OPs residues in the food chain and biomarkers of exposure. The Gas Chromatography–Flame Photometric Detector method was employed to examine the relationship between OPs residue and DAPs (Diakly phosphate) in four targeted locations in Thailand, as well as to examine the residues of OPs in vegetable samples and DAPs in 395 school children’s urine samples. Vegetables were found to contain at least one OP, with chlorpyrifos being the most prevalent. The OPs detected frequencies for Sakon Nakhon, Chiang Mai, Phang Nga, and Pathum Thani are 96.1%, 94%, 91.7%, and 83.3%, respectively. The overall centration level of OPs showed 0.3261 mg/kg, 0.0636 mg/kg, 0.0023 mg/kg, 0.0150 mg/kg, 0.2003 mg/kg, 0.0295 mg/kg, and 0.0034 mg/kg for diazinon, dimethoate, pirimiphos-methyl, chlorpyrifos, profenofos, ethion, and triazophos, respectively. Nearly 98% of school children were detected with at least one DAP. The overall level of dimethyl phosphate metabolites (5.258 µmole/mole creatinine) in urine samples is higher than diethyl phosphate metabolites (2.884 µmole/mole creatinine), especially in the case of Pathum Thani. Our findings show a consistent relationship between OPs in vegetables from wet markets and DAPs in urine samples of school children in various parts of Thailand.

Health risk assessment of pesticide residue in freshly harvested Vigna subterranea (Bambara nut) in Nsukka South Eastern Nigeria.

Two species of freshly harvested Bambara nut were analyzed for organophosphate and organochlorine pesticide residue using GC-FID and GC-ECD. The risk associated with the consumption of the Bambara nut was evaluated using the health risk index (HRI) and the probable cancer risk (PCR). A maximum of thirteen (13) organochlorines and eight (8) organophosphate pesticides were determined from both species respectively. The results revealed that almost all the quantified pesticides exceeded their respective FAO maximum residue levels (MRLs). The health risk index (HRI) values of the organochlorines and organophosphates were below 1 in adults indicating little or no risk to adults. While the HRI of the organophosphates and a few values in the organochlorines were above 1 in children indicating that organophosphate pesticides in the freshly harvested white and mixed Bambara nut could pose a great health risk to children within these areas. The Hierarchical Cluster Dendrogram indicated similar sources of the assessed organochlorine and organophosphate pesticides.

Effect of Planting Season on the Residue of Organophosphate in Chili (Capsicum annuum L.)

Background: Pesticide residues harm human health and are associated with hemopoietic disorders and many organ cancers. This study analyzes the pesticide residue content in chili cultivated by farmers in rainy and dry seasons, especially for organophosphates pesticides. The residual difference in chili was affected by planting seasons caused by farmers’ adoption of crop cultivation technologies, including pesticide application. Methods: The analysis was carried out using gas chromatography on 26 samples from 13 chili cultivation locations in Aceh province, Indonesia. Sixteen samples were harvested during the rainy season and the remaining ten were harvested during the dry season. Result: The results showed that pesticide residues were found in two red chili samples planted in the rainy season, while no residue was found from the dry season. In the rainy season’s harvested samples, the Organophosphate pesticide residues were chlorpyrifos 0.52 mg kg-1 and 0.16 mg kg-1 at Mutiara Tiga sub-district and Meurebo sub-district, respectively. From Meurebo sub-district profenofos 0.74 mg kg-1 was found. All detected pesticide residues samples are still below the maximum residue limit (MRL) set by the Government of Indonesia and CODEX Alimentarius.

Estimation and human health risk assessment of organochlorine and organophosphate pesticide residues in raw milk collected in Kenya

Background: This study determined the levels of organochlorine (OCPs) and organophosphate (OPPs) pesticide residues in cow milk from Kiambu and camel milk from Isiolo and Laikipia. The human dietary intake and the potential consumer health risks were also evaluated. Methods: In total, 90 cow and 82 camel milk samples were collected and analyzed using gas chromatography tandem mass spectroscopy to determine the levels of OCPs and OPPs. The levels were compared to the maximum residue limits (MRLs) established by the Codex Alimentarius (CA), EU Pesticides Database (EUPD), and the United States Department of Agriculture. The estimated daily intake and chronic hazard quotient (cHQ) of the milk were also calculated. Results: Cow milk from Kiambu was contaminated with 11/18 of the evaluated OCPs and 13/14 of the evaluated OPPs while camel milk from Isiolo was contaminated with 9/18 of the evaluated OCPs and 9/14 of the evaluated OPPs. Camel milk from Laikipia was contaminated with 11/18 of the evaluated OCPs and 11/14 of the evaluated OPPs. The mean heptachlor value in camel milk from Isiolo was above the EUPD MRLs. The mean value of heptachlor in Camel milk from Laikipia was above the CA and EUPD MRLs. The cHQs for Disulfoton, Fenamiphos, and Methacrifos in Cow milk were above 1 for adults and children. The cHQs for Fenchlorphous and Profenofos in Camel milk were above 1 for adults and children. The cHQs for α-endosulphan, β-endosulphan, dieldrin, and heptachlor in cow milk was above 1 for adults and children while the cHQs for heptachlor in camel milk was above 1 for adults and children. Conclusions: The potential health risks from chronic dietary intake of cow and camel milk in Kenya cannot be excluded. The routine monitoring of organophosphate and organochlorine pesticide levels in milk is recommended to minimize risks to human health.

A critical comparison between an ultra-high-performance liquid chromatography triple quadrupole mass spectrometry (UHPLC-QqQ-MS) method and an enzyme assay for anti-cholinesterase pesticide residue detection in cereal matrices.

Analytical method development for the control of pesticide residues occurring in significant dietary foodstuffs is of utmost importance considering their potential impact on consumer health and food market sustainability. Depending on the purpose, either instrumental analysis, mainly chromatographic methods, or screening assays, mostly using biorecognition affinity, are commonly used, featuring different advantages and drawbacks. To practically compare these two different types of analytical strategies, we applied them for the detection of (i) 97 organophosphate (OP) and carbamate (CM) pesticide residues in wheat flour and (ii) carbofuran (a carbamate insecticide) in wheat, rye and maize flour samples. Regarding high-end analysis, an ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ-MS) method was developed and validated achieving low limits of quantification (LOQs, from 0.002 to 0.040 mg kg-1) and a short chromatographic run (12 min). In terms of bioanalytical methods, a fast (17 min) and cost-efficient (∼0.01€ per sample) acetylcholinesterase (AChE) microplate assay for carbofuran screening was utilized. Importantly, carbofuran was the strongest of the 11 OP and CM tested pesticides achieving a half maximal inhibitory concentration (IC50) of 0.021 μM whilst the assay detectability was at the parts per billion level in all three cereal matrices. Based on the attained results, a critical discussion is presented providing the analytical merits and bottlenecks for each case and a wider outlook related to the application of analytical methods in the food safety control analytical scheme.