Carbofuran self-poisoning: forensic and analytic investigations in twins and literature review.

Carbofuran is a pesticide widely used in agricultural context to kill insects, mites, and flies by ingestion or contact. Along with literature review, we aimed to (i) present the clinical, autopsy, and toxicological findings of carbofuran self-poisonings in two 69-year-old twins, resulting in the death of one of them and (ii) assess carbofuran metabolite distribution using molecular networking. Quantitative analysis of carbofuran and its main metabolites (3-hydroxycarbofuran and 3-ketocarbofuran) was carried out using an original liquid chromatography-tandem mass spectrometry method on biological samples (cardiac or peripheral blood, urine, bile, and gastric contents). Toxicological analysis of post-mortem samples (twin 1) highlighted high concentrations of carbofuran and its metabolites in cardiac blood, bile, and gastric contents. These compounds were also quantified in blood and/or urine samples of the living brother (twin 2), confirming poisoning. Using molecular networking approach to facilitate visualization of mass spectrometry datasets and sample-to-sample comparisons, we detected two more metabolites (7-phenol-carbofuran and 3-hydroxycarbofuran glucuronide) in bile (twin 1) and urine (twin 2). These results highlight the value of (i) these compounds as carbofuran consumption markers and (ii) bile samples in post-mortem analysis to confirm poisoning. From an analytical point of view, molecular networking allowed the detection and interpretation of carbofuran metabolite ammonium adducts which helped to confirm their identification annotations, as well as their structural data. From a clinical point of view, the different outcomes between the two brothers are discussed. Overall, these cases provide novel information regarding the distribution of carbofuran and its metabolites in poisoning context.

Waveguide-Based Fluorescent Immunosensor for the Simultaneous Detection of Carbofuran and 3-Hydroxy-Carbofuran.

Carbofuran (CBF) is an efficient and broad-spectrum insecticide. As testing indicators for water quality and agricultural products, CBF and its metabolite 3-hydroxy-carbofuran (3-OH-CBF) are regulated by many countries. The detection of CBF and 3-OH-CBF is of great importance for the environment and human health. However, an immunosensor detection method for the simultaneous analysis of CBF and 3-OH-CBF remains unavailable. Herein, we report a waveguide-based fluorescent immunosensor for detecting CBF and 3-OH-CBF, synchronously. The immunosensor is based on a broad-spectrum monoclonal antibody with high binding affinity against CBF and 3-OH-CBF. The linear detection ranges for CBF and 3-OH-CBF are 0.29-2.69 and 0.12-4.59 µg/L, with limits of detection of 0.13 µg/L for CBF and 0.06 µg/L for 3-OH-CBF, respectively. The whole detection process for each cycle is approximately 30 min. The results show a good application prospect for the rapid detection of CBF and 3-OH-CBF in water or agricultural products.

Bioaccumulation and Metabolism of Carbosulfan in Zebrafish (Danio rerio) and the Toxic Effects of Its Metabolites.

Carbosulfan is a carbamate insecticide that has been widely used in agriculture. However, studies showed that carbosulfan could be highly toxic to aquatic organisms. The metabolism of carbosulfan in adult zebrafish is still largely unexplored, and the metabolites in individual or in combination may pose a potential threat to zebrafish. In the present study, the bioaccumulation and metabolism of carbosulfan in zebrafish (Danio rerio) were assessed, and the main metabolites, including carbofuran and 3-hydroxycarbofuran, were determined. The toxicity of carbosulfan and its metabolites individually or in combination to zebrafish was also investigated. The bioaccumulation and metabolism experiment indicated that carbosulfan was not highly accumulated in zebrafish, with a bioaccumulation factor of 18 after being exposed to carbosulfan for 15 days, and the metabolism was fast, with a half-life of 1.63 d. The two main metabolites were relatively persistent, with half-lives of 3.33 and 5.68 d for carbofuran and 3-hydroxycarbofuran, respectively. The acute toxicity assay showed that carbofuran and 3-hydroxycarbofuran had 96-h LC50 values of 0.15 and 0.36 mg/L, showing them to be more toxic than carbosulfan (96-h LC50 = 0.53 mg/L). Combinations of binary or ternary mixtures of carbosulfan and its metabolites displayed coincident synergistic effects on acute toxicity, with additive index (AI) values of 1.9-14.3. In the livers and gills of zebrafish exposed to carbosulfan, carbofuran, and 3-hydroxycarbofuran, activities of catalase, superoxide dismutase, and glutathione-S-transferase were significantly changed in most cases, and the content of malondialdehyde was greatly increased, indicating that carbosulfan and its metabolites induced varying degrees of oxidative stress. The metabolites were more persistent and toxic to zebrafish and exhibit coincident synergistic effects in combination. These results can provide evidence for the potential risk of pesticides and highlight the importance of a systematic assessment for the combination of the precursor and its metabolites.

Persistence and metabolism of carbofuran in the soil and sugarcane plant.

Persistence and metabolism of carbofuran in the soil and sugarcane plant were studied under tropical sugarcane ecosystem. Residues of carbofuran and its metabolites in the soil, sugarcane leaf, and juice were determined by employing matrix-specific sample preparation methods and gas chromatography equipped with mass spectrometry. The recoveries of carbofuran, 3-keto carbofuran, and 3-hydroxy carbofuran were in the range of 88.75 ± 2.58-100.25 ± 2.38, 90.38 ± 2.61-98.24 ± 4.78, and 89.25 ± 3.11-98.10 ± 3.19%, respectively, at three levels of fortification across the three matrices involved in the study. At recommended dose (carbofuran 3% CG at 2 kg a.i./ha), the initial deposit of carbofuran in the soil was 14.390 ± 1.727 µg/g. The total residues comprising both carbofuran and 3-hydroxy carbofuran were detected up to 105 days after treatment with the half-life of 10.83 days. The parent compound and its metabolite were detected and quantified in the sugarcane plant (leaves and juice) from 14 days after application of carbofuran in the soil. The total residues (carbofuran and 3-hydroxy carbofuran) were detected in the leaves and cane juice up to 75 and 30 days after treatment, respectively.

Development and validation of carbofuran and 3-hydroxycarbofuran analysis by high-pressure liquid chromatography with diode array detector (HPLC-DAD) for forensic Veterinary Medicine.

Agricultural pesticides used with the criminal intent to intoxicate domestic and wild animals are a serious concern in Veterinary Medicine. In order to identify the pesticide carbofuran and its metabolite 3- hydroxycarbofuran in animals suspected of exogenous intoxication a high pressure liquid chromatography with diode array detector (HPLC-DAD) method was developed and validated in stomach contents, liver, vitreous humor and blood. The method was evaluated using biological samples from seven different animal species. The following parameters of analytical validation were evaluated: linearity, precision, accuracy, selectivity, recovery and matrix effect. The method was linear at the range of 6.25-100µg/mL and the correlation coefficient (r2) values were >0.9811 for all matrices. The precision and accuracy of the method was determined by coefficient of variation (CV) and the relative standard deviation error (RSE), and both were less than 15%. Recovery ranged from 74.29 to 100.1% for carbofuran and from 64.72 to 100.61% for 3-hydroxycarbofuran. There were no significant interfering peaks or matrix effects. This method was suitable for detecting 25 positive cases for carbofuran amongst a total of 64 animal samples suspected of poisoning brought to the Toxicology Diagnostic Laboratory, School of Veterinary Medicine and Animal Sciences, University of Sao Paulo.

Carbofuran degraded by iron-doped anatase: Weakening the cholinesterase inhibitory activity in the photoproducts mixture.

Carbofuran is a toxic carbamate pesticide, and its use has increased in recent years. While marketing information indicates stability in different chemical media, carbofuran exhibits relative photolability. The aim of this research was to decompose carbofuran and to identify the photoproducts achieved when two different doped titania photocatalysts were employed under UV irradiation. The iron-doped TiO2 materials were obtained (a) via a hydrothermal method and (b) by an ultrasound-assisted sol-gel method. The precursors were TiOSO4⋅xH2O and Fe3(NO3)·9H2O. X-ray studies confirmed that the anatase phase of the iron-doped TiO2 resulted from the two preparation methods. The photocatalytic performance of the prepared materials was monitored by LC/ESI-QTOF-MS, enabling the identification of photoproducts: oxo-carbamates, hydroxylated benzofuranes, a carboxamide, and one amine. By using the iron-doped TiO2 materials, 2,2-dimethyl-2,3-dihydrobenzofuran-3,7-diol was the most abundant photoproduct, and N,2,2-trimethyl-2,3-dihydrobenzofuran-7-amine was the only compound that had not been previously reported in the photolysis and photocatalysis of carbofuran. The product 3-hydroxy carbofuran, a cholinesterase inhibitor, was quantified and was found to be transformed into compounds that lack this inhibitive property.

Removal of carbamates and detoxification potential in a biomixture: Fungal bioaugmentation versus traditional use.

The use of fungal bioaugmentation represents a promising way to improve the performance of biomixtures for the elimination of pesticides. The ligninolyitc fungus Trametes versicolor was employed for the removal of three carbamates (aldicarb, ALD; methomyl, MTM; and methiocarb, MTC) in defined liquid medium; in this matrix ALD and MTM showed similar half-lives (14d), nonetheless MTC exhibited a faster removal, with a half-life of 6.5d. Then the fungus was employed in the bioaugmentation of an optimized biomixture to remove the aforementioned carbamates plus carbofuran (CFN). Bioaugmented and non-bioaugmented systems removed over 99% ALD and MTM after 8d of treatment, nonetheless a slight initial delay in the removal was observed in the bioaugmented biomixtures (removal after 3d: ALD 87%/97%; MTM 86%/99%, in bioaugmented/non-bioaugmented systems). The elimination of the other carbamates was slower, but independent of the presence of the fungus: >98% for MTM after 35d and >99.5% for CFN after 22d. Though the bioaugmentation did not improve the removal capacity of the biomixture, it favored a lower production of transformation products at the first stages of the treatment, and in both cases, a marked decrease in the toxicity of the matrix was swiftly achieved along the process (from 435 to 448 TU to values <1TU in 16d).

Residues of carbosulfan and its metabolites carbofuran and 3-hydroxy carbofuran in rice field ecosystem in China.

The fate of carbosulfan (seed treatment dry powder) was studied in rice field ecosystem, and a simple and reliable analytical method was developed for determination of carbosulfan, carbofuran, and 3-hydroxyl carbofuran in brown rice, rice straw, paddy water, and soil. The target compounds were extracted using acetonitrile or dichloromethane, cleaned up on acidic alumina or florisil solid phase extraction (SPE) cartridge, and analyzed by gas chromatography. The average recoveries of carbosulfan, carbofuran and 3-hydroxy carbofuran in brown rice, rice straw, paddy water, and soil ranged from 72.71% to 105.07%, with relative standard deviations of 2.00-8.80%. The limits of quantitation (LOQs) of carbosulfan, carbofuran and 3-hydroxy carbofuran in the samples (brown rice, rice straw, paddy water and soil) were 0.011, 0.0091, 0.014, 0.010 mg kg(-1), 0.016, 0.019, 0.025, 0.013 mg kg(-1), and 0.031, 0.039, 0.035, 0.036 mg kg(-1), respectively. The trials results showed that the half-lives of carbosulfan, carbofuran and 3-hydroxy carbofuran in rice straw were 4.0, 2.6 days, 3.9, 6.0 days, and 5.8, 7.0 days in Zhejiang and Hunan, respectively. Carbosulfan, carbofuran and 3-hydroxy carbofuran were detected in soils. Carbosulfan and 3-hydroxy carbofuran were almost undetectable in paddy water. Carbofuran was detected in paddy water. The final residues of carbosulfan, carbofuran and 3-hydroxy carbofuran in brown rice were lower than 0.05 mg kg(-1), which were lower than 0.5 mg kg(-1) (MRL of carbosulfan) or 0.1 mg kg(-1) (MRL of carbofuran). Therefore, a dosage of 420 g active ingredient per 100 kg seed was recommended, which could be considered as safe to human beings and animals. These would contribute to provide the scientific basis of using this insecticide.

Adaptation of biomixtures for carbofuran degradation in on-farm biopurification systems in tropical regions.

A biomixture constitutes the active core of the on-farm biopurification systems, employed for the detoxification of pesticide-containing wastewaters. As biomixtures should be prepared considering the available local materials, the present work aimed to evaluate the performance of ten different biomixtures elaborated with by-products from local farming, in the degradation of the insecticide/nematicide carbofuran (CFN), in order to identify suitable autochthonous biomixtures to be used in the tropics. Five different lignocellulosic materials mixed with either compost or peat and soil were employed in the preparation of the biomixtures. The comprehensive evaluation of the biomixtures included removal of the parent compound, formation of transformation products, mineralization of radiolabeled CFN, and determination of the residual toxicity of the process. Detoxification capacity of the matrices was high, and compost-based biomixtures showed better performance than peat-based biomixtures. CFN removal over 98.5% was achieved within 16 days (eight out of ten biomixtures), with half-lives below 5 days in most of the cases. 3-Hydroxycarbofuran and 3-ketocarbofuran were found as transformation products at very low concentrations suggesting their further degradation. Mineralization of CFN was also achieved after 64 days (2.9 to 15.1%); several biomixtures presented higher mineralization than the soil itself. Acute toxicity determinations with Daphnia magna revealed a marked detoxification in the matrices at the end of the process; low residual toxicity was observed only in two of the peat-based biomixtures. Overall best efficiency was achieved with the biomixture composed of coconut fiber-compost-soil; however, results suggest that in the case of unavailability of coconut fiber, other biomixtures may be employed with similar performance.

Simultaneous in situ quantification of two cellular lipid pools using orthogonal fluorescent sensors.

Lipids regulate a wide range of biological activities. Since their local concentrations are tightly controlled in a spatiotemporally specific manner, the simultaneous quantification of multiple lipids is essential for elucidation of the complex mechanisms of biological regulation. Here, we report a new method for the simultaneous in situ quantification of two lipid pools in mammalian cells using orthogonal fluorescent sensors. The sensors were prepared by incorporating two environmentally sensitive fluorophores with minimal spectral overlap separately into engineered lipid-binding proteins. Dual ratiometric analysis of imaging data allowed accurate, spatiotemporally resolved quantification of two different lipids on the same leaflet of the plasma membrane or a single lipid on two opposite leaflets of the plasma membrane of live mammalian cells. This new imaging technology should serve as a powerful tool for systems-level investigation of lipid-mediated cell signaling and regulation.

Analysis of carbofuran, carbosulfan, isoprocarb, 3-hydroxycarbofuran, and 3-ketocarbofuran by micellar electrokinetic chromatography.

We developed an analytical method for the detection and quantitation of five pesticides and some of their metabolites - 3-hydroxycarbofuran, 3-ketocarbofuran, carbofuran, carbosulfan, and isoprocarb - using micellar electrokinetic chromatography coupled with a UV-Vis detector. The optimum separation conditions were 20 mM phosphate buffer (pH 8.0) containing 15 mM sodium dodecyl sulfate. The detection wavelength was set at 200 nm and the applied voltage was 12.5 kV. Under these conditions, baseline separation of five pesticides was achieved in 15 min, and the detection limits (S/N = 3) of 3-hydroxycarbofuran, 3-ketocarbofuran, carbofuran, carbosulfan, and isoprocarb were 0.3, 0.3, 0.3, 4.0, and 0.3 µM, respectively. The linear ranges for 3-hydroxycarbofuran, 3-ketocarbofuran, carbofuran, and isoprocarb were between 1.0 and 50.0 µM and that for carbosulfan was between 10.0 and 100.0 µM, with R(2) larger than 0.995. When applied to the analysis of a carbofuran-spiked rice sample, this approach yielded results with excellent repeatability (3.3%, n = 5), reproducibility (4.5%, n = 5), separation efficiency (>2.1 × 10(4) theoretical plates), and recovery (95.5 ± 1.4%, n = 5).

Degradation of carbofuran derivatives in restricted water environments: basic hydrolysis in AOT-based microemulsions.

The effect of sodium bis(2-ethylhexyl)sulfosuccinate/isooctane/water microemulsions on the stability of 2,2-dimethyl-2,3-dihydro-1-benzofuran-7-yl methylcarbamate (carbofuran, CF), 3-hydroxy-2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate (3-hydroxycarbofuran, HCF) and 3-keto-2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate (3-ketocarbofuran, KCF) in basic media has been studied. The presence of these microheterogeneous media implies a large basic hydrolysis of CF and HCF on increasing surfactant concentration and, also, on increasing water content in the microemulsion. The hydrolysis rate constants are approximately 2- and 10-fold higher than those in pure water for HCF and CF, respectively. In contrast, a steep descent in the rate of decomposition for KCF was observed. These behaviours can be ascribed to the presence of CF derivatives both in the hydrophilic phase and in the lipophilic phase, while the hydroxyl ions are only restricted to the water pool of the microemulsion (hydrophilic phase). The kinetic rate constants for the basic hydrolysis in AOT-based microemulsions have been obtained on the basis of a pseudophase model. Taking into account that an important part of soils are colloids, the possibility of the presence of restricted water environments implies that soil composition and its structure will play an important role in the stability of these carbamates. In fact, we observed that the presence of these restricted aqueous media in the environment, in particular in watersheds and in wastewaters, could reduce significantly the half-life of these pesticides (33% and 91% for HCF and CF, respectively).

Surprising hair analysis results following acute carbofuran intoxication.

We present two non fatal cases of intoxication with carbofuran (CBF) documented by hair analysis. Carbofuran and 3-hydroxycarbofuran (OHCBF, its main metabolite) hair concentrations were determined using a liquid chromatography-tandem mass spectrometry method. The obtained results were surprising if we consider several hair analyses previously published and based on a theory of the presence of xenobiotic in the only segment that comprised its intake. Among the two intoxication cases, we noticed the presence of CBF and OHCBF in hair segments corresponding to 45 days before, and more than 100 days after, the day of intoxication. Additionally, repeated hair samplings and subsequent analysis revealed a decrease of the carbofuran's concentration during the hair life.

Soil and water contamination with carbofuran residues in agricultural farmlands in Kenya following the application of the technical formulation Furadan.

This study was undertaken to determine the concentrations of carbofuran residues in water, soil and plant samples from selected sites in the farmlands in Kenya and to demonstrate the impact of Furadan use on the local environment. Soil, water and plant samples obtained from agricultural farmlands where the technical formulation Furadan has been used extensively showed high environmental contamination with concentrations of carbofuran and its two toxic metabolites 3-hydroxycarbofuran and 3-ketocarbofuran, separately, ranging from 0.010-1.009 mg/kg of dry surface soil, 0.005-0.495 mg/L in water samples from two rivers flowing through the farms and bdl-2.301 mg/L in water samples from ponds and dams located close to the farms. Maize plant samples contained these residues in concentrations ranging from 0.04-1.328 mg/kg of dry plant tissue. The significantly high concentration levels of carbofuran and its metabolites, 3-ketocarbofuran and 3-hydroxycarbofuran, found in various matrices demonstrate that Furadan was used extensively in the two areas and that there was environmental distribution and exposure of residues in water which posed risks when used for domestic purposes or as drinking water for animals in two wildlife conservancies where the dams and ponds are located. Surface soil contamination was also high and posed risks through run-off into the dams and rivers as well as through secondary exposure to small birds and mammals.

Carbofuran poisoning detected by mass spectrometry of butyrylcholinesterase adduct in human serum.

Carbofuran is a pesticide whose acute toxicity is due to inhibition of acetylcholinesterase. Butyrylcholinesterase (BChE) in plasma is inhibited by carbofuran and serves as a biomarker of poisoning by carbofuran. The goal was to develop a method to positively identify poisoning by carbofuran. Sera from an attempted murder and an attempted suicide were analyzed for the presence of carbofuran adducts on BChE. The BChE from 1 ml of serum was rapidly purified on a 0.2 ml procainamide-Sepharose column. Speed was essential because the carbofuran-BChE adduct decarbamylates with a half-life of about 2 h. The partially purified BChE was boiled to denature the protein, thus stopping decarbamylation and making the protein vulnerable to digestion with trypsin. The labeled peptide was partially purified by HPLC before analysis by LC/MS/MS in the multiple reaction monitoring mode on the QTRAP 2000 mass spectrometer. Carbofuran was found to be covalently bound to Ser 198 of human BChE in serum samples from two poisoning cases. Multiple reaction monitoring triggered MS/MS spectra positively identified the carbofuran-BChE adduct. In conclusion a mass spectrometry method to identify carbofuran poisoning in humans has been developed. The method uses 1 ml of serum and detects low-level exposure associated with as little as 20% inhibition of plasma butyrylcholinesterase.

Hair analysis to document non-fatal pesticide intoxication cases.

We reported two non-fatal cases of intoxication with pesticides namely alachlor and carbofuran. Hair stand samples were collected from two men approximately 1 year after alachlor intoxication for case 1, and 14 days after the last exposure for case 2. Hair analysis was performed using a liquid chromatography-tandem mass spectrometry method. In case 1, alachlor was detected in the 5 analysed hair segments (concentrations between 12 and 136 pg/mg) and its metabolites were not detected. In case 2, carbofuran and its main metabolite (3-hydroxycarbofuran) were detected in the hair strand (global analysis) at the concentrations of 207 and 164 pg/mg, respectively. However, additional data are required in order to interpret such results.

Fungal biodegradation of carbofuran and carbofuran phenol by the fungus Mucor ramannianus: identification of metabolites.

The fungus Mucor ramannianus was tested to elucidate the biological fate of a class of N-methyl carbamate pesticide carbofuran and its hydrolysed form carbofuran phenol. The elution profile obtained from analysis by high-pressure liquid chromatography equipped with a reverse-phase C-18 column showed that two peaks occurred after incubation of M. ramannianus with which 1 mM carbofuran was combined as a final concentration. In culture of M. ramannianus with 1 mM carbofuran phenol, it produced two other metabolites compared to metabolites of carbofuran. LC/MS analysis suggested that two of the metabolites produced from carbofuran phenol were most likely to be 2-hydoxy-3-(3-methylpropan-2-ol)phenol or 7a-(hydroxymethyl)-2,2-dimethylhexahydro-6H-furo[2,3-b]pyran-6-one and 3-hydroxycarbofuran-7-phenol.

Liquid chromatography quadrupole time-of-flight mass spectrometry analysis of carbosulfan, carbofuran, 3-hydroxycarbofuran, and other metabolites in food.

The potential of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QqTOF-MS) to identify and confirm carbosulfan and seven of its main metabolites (carbofuran, 3-hydroxycarbofuran, 3-ketocarbofuran, 3-hydroxy-7-phenol carbofuran, 3-keto-7-phenolcarbofuran, 7-phenolcarbofuran, dibutylamine) at trace levels from food is explored for the first time. The analytical method developed consists of pressurized liquid extraction (PLE) and LC-QqTOF-MS in positive ion mode, which attains unequivocal identification and quantification of the studied compounds in food, at levels well below of those of concern (0.05 mg/kg for the sum of carbosulfan, carbofuran, and 3-hydroxycarbofuran). PLE recoveries ranged from 55 to 94% with limits of quantification from 10 (for carbosulfan, carbofuran, 3-hydroxycarbofuran, and dibutylamine) to 70 microg/kg (3-keto-7-phenolcarbofuran). The method is precise, with relative standard deviations varying between 5 and 11% for the repeatability (within-day) and 8-13% for the reproducibility (interday). This method was used to monitor the presence and fate of the target compounds in orange, potato, and rice crops treated with a commercial product containing carbosulfan. Field degradation studies show that carbofuran, 3-hydroxycarbofuran, and dibutylamine are the main degradation products formed in the environmental disappearance of carbosulfan.

Comparison of four mass analyzers for determining carbosulfan and its metabolites in citrus by liquid chromatography/mass spectrometry.

Four liquid chromatography/mass spectrometry (LC/MS) systems, equipped with single quadrupole, triple quadrupole (QqQ), quadrupole ion trap (QIT) and quadrupole time-of-flight (QqTOF) mass analyzers, were evaluated for the analysis of carbosulfan and its main transformation products. The comparison of quantitative aspects (sensitivity, precision and accuracy) was emphasized. Results showed that the triple quadrupole instrument reaches at least 20-fold higher sensitivity (LOD from 0.04 to 0.4 microg kg(-1)) compared to the single quadrupole (4-70 microg kg(-1)), the QIT (4-25 microg kg(-1)) and the QqTOF (4-23 microg kg(-1)) instruments. Recoveries were over 70% for all the analytes, except dibutylamine and 7-phenolcarbofuran. Repeatabilities (within-day) were slightly better by the single quadrupole (5-10%) and the QqQ (5-9%) than by the QIT (12-16%) and the QqTOF (9-16%). Both the QqTOF and QIT offer a linear dynamic range of two orders of magnitude whereas the single quadrupole and QqQ of, at least, three orders of magnitude. The method was applied to analyze carbosulfan field-treated orange samples, in which carbosulfan, carbofuran, 3-hydroxycarbofuran, and dibutylamine were found. As an example, the mean carbosulfan concentration was 20 +/- 0.6 microg kg(-1) measured by the QqQ, 22 +/- 1.2 microg kg(-1) by the single quadrupole, 25 +/- 2.8 microg kg(-1) by the QIT, and 20 +/- 1.8 microg kg(-1) by the QqTOF. Although the QqQ is more sensitive and precise, the mean values obtained by the four instruments are acceptable and comparable. The potential of each technique for the verification of the identity of residues detected in oranges is discussed using the concept of identification points.