Tap Samples Research Articles

A fast and sensitive analytical procedure for monitoring of synthetic pyrethroid pesticides' metabolites in environmental water samples

In this paper, we report a simple, fast, and sensitive analytical procedure for monitoring of synthetic pyrethroid pesticides' (SPPs') metabolites in environmental water samples using a novel vortex-assisted salt-induced liquid-liquid microextraction (VA-SI-LLME) method coupled with liquid chromatography/tandem mass spectrometric (LC-MS/MS) analysis. VA-SI-LLME was carried out by taking 4 mL of sample solution followed by the addition of isopropanol and ethyl acetate (0.4 mL, 1:2, v/v) as a binary extraction solvent, and 4 g of ammonium sulfate for phase separation. Then, the mixture solution was vortex for 2 min and centrifuged for 3 min to collect the extractant and inject into LC-MS/MS for analysis. Experimental factors affecting the VA-SI-LLME including extraction solvent, extraction solvent volume, salt type, amount of salt, extraction time, and sample pH were completely optimized. The developed analytical method was validated, and the results exhibited good linearity in the concentration ranges between 0.01–100 ng mL−1 with the correlation coefficient (r2) >0.992 for the target SPPs' metabolites. Excellent limit of quantification and precision were achieved in the range between 0.01–0.1 ng mL−1, and 1.55–5.06% (in terms relative standard deviation), respectively. The developed method was employed to determine the target SPPs' metabolites in tap, lake, river water, and influent wastewater samples collected in Kaohsiung city area, Taiwan. The extraction recoveries of spiked samples were satisfactory. Therefore, the presented method can be used as a potential alternative analytical procedure for monitoring of pesticides' metabolites in aqueous samples.

Pyrene-SH functionalized OTFT for detection of Hg2+ ions in aquatic environments

Abstract Mercury ion (Hg2+) sensor based on bottom gate top contact organic thin film transistor (OTFT) was fabricated. The OTFT channel area was functionalized with pyrene that contain thiol group, which has strong binding affinity toward Hg2+ ion. The OTFT sensor exhibited a charge mobility of 0.28 cm2 V−1 s−1, a threshold voltage of −22.3 V and on-to-off ratio 103. The sensor shows high selectivity to Hg2+ ion over other two valence metal ions. OTFT sensor exhibited high sensitivity to Hg2+ ion, indicated by increasing of drain current after exposed to different concentration of Hg2+ ion ranging from 1 mM to 0.01 μM. Moreover, the OTFT sensor capability for practical application was also demonstrated by sensing the present of 25 μM of Hg2+ ion in tap, drinking and seawater samples.

Simultaneous determination of 4-tert-octylphenol, chlorpyrifos-ethyl and penconazole by GC–MS after sensitive and selective preconcentration with stearic acid coated magnetic nanoparticles

Endocrine disruptive compounds are widely used and well-known chemicals that could alter some vital processes taking place in living organisms. These chemicals might cause serious health disorders such as different types of cancer, sexual anorexia and mood disorders. In this study, combination of stearic acid coated magnetic nanoparticles based dispersive solid-phase extraction method (DSPE) and gas chromatography–mass spectrometry (GC–MS) instrumentation was used for the extraction/preconcentration of 4-tert-octylphenol, chlorpyrifos-ethyl and penconazole from aqueous samples. All the extraction parameters such as the amount of nanoparticles, duration of the interaction, the type and the amount of the eluent were optimized. As a result of optimization studies, limit of detection values were found to be 0.41 μg/L for 4-tert-octylphenol, 0.33 μg/L for penconazole and 9.77 μg/L for chlorpyrifos-ethyl. In order to investigate the accuracy and the applicability of the developed method in different matrices, recovery studies were performed in tap and wastewater samples. The results showed that the method is accurate and sensitive for the analytes of interest and applicable in different matrices with high recovery results.

A fluorescent turn-on probe for Hg2+ with a high contrast designed by manipulating functional groups tethered to naphthalimide

Based on the concept provided by our previous work on a fluorescent Cd2+ probe, a fluorescent turn-on Hg2+ probe with a high contrast was designed through manipulating functional groups tethered to naphthalimide. With carbamoylmethylamino and bis[2-(ethylthio)ethyl]amino groups as tethering functionalities, 1 worked as a useful fluorescent probe in a high selective and sensitive manner over the pH range between 6 and 8 with a detection limit at 2.8 nM (estimated at a pH of 7.2). Comparison of the probe performance of 1 with that of 2 merely with bis[2-(ethylthio)ethyl]amino group suggested that both of the tethering groups exhibited their abilities to chelate with Hg2+, and yet the carbamoylmethylamino group also functioned as a fluorescent off-on switch through a photoinduced electron transfer mechanism. Thus, 1 found a practical utility as an Hg2+ probe in analysis of river as well as tap samples without any tedious pretreatments.

Accurate and Sensitive Analytical Strategy for the Determination of Antimony: Hydrogen Assisted T-Shaped Slotted Quartz Tube-Atom Trap-Flame Atomic Absorption Spectrometry.

Antimony is known to have some adverse health effects on human health. Flame atomic absorption spectrometry (FAAS) is a widely used instrumental for the determination of antimony and other metals. However, it lacks the sensitivity to determine these metals at trace levels. This study was aimed at overcoming this setback by using hydrogen assisted T-shaped slotted quartz tube technique to preconcentrate and determine antimony by FAAS. All the system parameters were optimized to enhance the detection power of the system. Under the optimum experimental conditions, the limits of detection and quantification were found to be 0.75 and 2.49µgL-1, respectively with R2 value of 0.9999. Accuracy of the developed method was validated by experimental results agreeing to the certified value of a standard reference material. Recovery studies were also carried out to determine the method's applicability to tap and mineral water samples, and the results obtained were appreciable.

Heavy Metals Analysis in Human Body (Toenail, Fingernail and Hair Samples) and Drinking Waters of Santa Fe Region, Argentina

This study provides an insight into a province of Santa Fe region of a developing country, namely San Cristobal and Huanqueros, Argentina and a possible link between arsenic, copper and iron concentration in toenail, fingernail and hair in the population. A multivariate statistical tool, known as Principal Component Analysis (PCA) was applied to explain the behaviour of the elements in toenails, fingernails, drinking waters and hair using multi- base 2013 excel add- ins. Correlation test, error bars, and a 2-factor ANOVA test were employed. Results from one hundred and twenty- nine (n=129) samples of tap well water (n=23), rainwater (n=20), bottled water (n=6) and treated well water (n=80) and each of toenail, fingernail and hair (n=129) samples from the subjects were determined and the results compared with the previous works. Mean, standard deviation, covariance and maximum and minimum for each variable were reported. The hypothesis is to understand if there is a correlation between fingernail and toenail metals levels and make a comparison with previous researches. Results show that a positive correlation exists between fingernail and toenail metals concentrations. Also, the study reveals higher concentrations of arsenic, copper and iron in the samples tissues compared with the values available in the previous works. The elevated levels of these metals may be attributed to the drinking water sources. Since this study highlighted elevated levels of these metals, consumptions of contaminated drinking water should be constantly monitored. Finally, the application of multivariate statistical techniques can provide powerful information on heavy metals bioaccumulation analysis in human and environment.

Microwave-assisted synthesis of thymine-functionalized graphitic carbon nitride quantum dots as a fluorescent nanoprobe for mercury(II).

A microwave-assisted hydrothermal method was employed to prepare thymine-modified graphitic carbon nitride quantum dots (T-gCNQDs) which are shown to be a novel fluorescent nanoprobe for Hg(II). They exhibit excellent optical properties (blue emission with a fluorescence quantum yield of 46%) and water solubility. The incorporation of thymine into the gCNQDs results in an enhancement in photoluminescence properties. It is found that fluorescence, best measured at excitation/emission wavelengths of 350/445nm, is much more strongly quenched by Hg(II) compared to the thymine-free nanoprobe. The quenching is highly selective even in the presence other metal ions. This is ascribed to the formation of T-Hg(II)-T base complexes. Fluorescence drops linearly in the 1.0 to 500nM Hg(II) concentration range, and the limit of detection is 0.15nM. The method was applied to the determination of Hg(II) in spiked samples of tap and pond water. Recoveries were found to be >95%, thus demonstrating the practical applicability of the assay. Graphical abstract A microwave-assisted hydrothermal route was employed to prepare thymine-functionalized graphitic carbon nitride QDs (T-gCNQDs). A selective fluorescence quenching mechanism occurred between T-gCNQDs and Hg(II) due to thymine functionalization. T-gCNQDs was utilized to detect Hg(II) in real samples.

Effect of halide ions on secondary electrospray ionization-ion mobility spectrometry for the determination of TNT extracted by dispersive liquid-liquid microextraction

In this study, secondary electrospray ionization source (SESI) was coupled with ion mobility spectrometer (IMS) and utilized for the determination of 2,4,6-trinitrotoluene (TNT) in water and wastewater samples. The sensitivity of SESI–IMS for TNT detection was compared with that obtained by ESI–IMS. The effect of different halide ions (as dopants) on the signal enhancement was evaluated and eventually KCl was selected as the most effective dopant. Sample preparation step for the pre-concentration of TNT was performed by dispersive liquid-liquid microextraction using an extraction solvent with the lower density than water. Methanol and toluene were selected as the disperser and extraction solvents, respectively. Some other affected parameters on the extraction efficiency; such as salt addition and sample acidity were also investigated. The linearity was obtained 4.0–175.0 μg L−1 and the limit of detection and quantification were calculated 1.0 and 4.0 μg L−1, respectively. Tap, River, and laboratory wastewater samples were selected to evaluate the method capability for determining the analyte in real matrices, and satisfactory analytical results were obtained.

Box–Behnken Experimental Design for the Synthesis of Magnetite–Polypyrrole Composite for the Magnetic Solid Phase Extraction of Non-steroidal Anti-inflammatory Drug Residues

ABSTRACTA magnetite–polypyrrole composite adsorbent was synthesized and applied for the magnetic solid phase extraction of three non-steroidal anti-inflammatory drugs in aqueous solution and systematically investigated using Box–Behnken design. The synthesized composite adsorbent was characterized using Fourier-transform infrared spectroscopy, transmission electron microscopy, the Brunauer–Emmett–Teller method, vibrating sample magnetometry, and X-ray diffraction. The material was successfully modeled by Box–Behnken design (R2 = 0.94–0.98, p value: <0.001%) by monitoring the extraction efficiencies of naproxen, diclofenac sodium, and mefenamic acid. The analytes were determined using high-performance liquid chromatography with ultraviolet detection. The polymerization time was found to be the most significant factor, followed by amount of oxidant and monomer in the synthesis of the composite with a fixed Fe3O4 mass. Box–Behnken design was employed for the optimization of four parameters affecting the magnetic solid phase extraction: sample pH, salt addition, adsorption, and desorption time (R2 = 0.88–0.94). The optimized conditions for the procedure were validated, providing low detection limits (0.9–3.5 µg L−1) with good reproducibility (<7.16% relative standard deviation) and excellent recoveries (97.87–100.49%) for tap, river, and wastewater samples. The synthesized adsorbent demonstrated good adsorption efficiency for the simultaneous determination of the non-steroidal anti-inflammatory drug residues.

A mixed-method examination of risk factors in the truck-to-cistern drinking water system on the Beardy’s and Okemasis First Nation Reserve, Saskatchewan

The provision of safe drinking water is a key driver of public health and a pressing health issue facing First Nations communities in Canada. Contaminated water is a perennial issue for reserve communities across the country despite numerous government investments. Many First Nations communities rely heavily on cistern use for their drinking water supply; however, bacterial contamination within these systems is frequent and a common reason for household boil water advisories. The sources of contamination during the process of hauling water to cisterns in First Nations communities have received limited attention in academic research. The purpose of this research is to identify the risks to water quality through the truck-to-cistern water system. In partnership with a Saskatchewan First Nations community, drinking water quality was monitored in the treatment plant, in delivery trucks and at 142 household cisterns and taps from July to October, 2014. Risks to water supply were identified through monthly water sampling and laboratory analysis, key informant interviews, and observation. Coliform contamination in trucks, cisterns and taps was most common during August. Total coliforms were more likely to be found in cisterns compared to household taps and samples from trucks. Chlorine residuals were lower in household tap samples than in cisterns for August and September. Together with the community, investigators identified contamination and bacteriological growth in cisterns and household distribution systems, and variable levels of total chlorine concentrations depending on month and site of sampling. Recommendations are provided for advancing guidelines on management of truck-to-cistern drinking water supply chains in First Nations.

In Situ Dielectric Barrier Discharge Trap for Ultrasensitive Arsenic Determination by Atomic Fluorescence Spectrometry.

The mechanisms of arsenic gas phase enrichment (GPE) by dielectric barrier discharge (DBD) was investigated via X-ray photoelectron spectroscopy (XPS), in situ fiber optic spectrometer (FOS), etc. It proved for the first time that the arsenic species during DBD trapping, release, and transportation to the atomic fluorescence spectrometer (AFS) are probably oxides, free atoms, and atom clusters, respectively. Accordingly, a novel in situ DBD trap as a GPE approach was redesigned using three-concentric quartz tube design and a modified gas line system. After trapping by O2 at 9.2 kV, sweeping for 180 s, and releasing by H2 at 9.5 kV, 2.8 pg detection limit (LOD) was achieved without extra preconcentration (sampling volume = 2 mL) as well as 4-fold enhancement in absolute sensitivity and ∼10 s sampling time. The linearity reached R2 > 0.998 in the 0.1-8 μg/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 100-106%; and the measurements of the certified reference materials (CRMs) were in good agreement with the certified values. In situ DBD trap is also suitable to atomic absorption spectrometry (AAS) or optical emission spectrometry (OES) for fast and on-site determination of multielements.

Analytical Confirmation of Various Herbicides in Drinking Water Resources in Sugarcane Production Regions of Guangxi, China.

This work investigated drinking water contamination by 11 commonly used herbicides in sugarcane production areas in Guangxi, China. The work developed an analytical method for determination of these herbicides in environmental waters. This work studied herbicide residues in drinking water in Guangxi, China. The maximum residues and percent of detects were: (0.091µg/L, 29.2%, atrazine), (0.018µg/L, 8.3%, ametryne), (0.188µg/L, 8.3%, aetolaehlor), (0.139µg/L, 4%, simazine), (0.585µg/L, 62.5%, atrazine), (0.311µg/L, 33.3%, acetochlor), (0.341µg/L, 58.3%, ametryne), (1.312µg/L, 29.2%, metolachlor), (0.088µg/L, 4.2%, alachlor), (0.127µg/L, 14.3%, atrazine), and (0.453µg/L, 7.1%, metolachlor), respectively. The results demonstrated that agricultural herbicides were detected in all water samples, including tap, surface and groundwater samples. Since the residues are generally below the safe limits established by the government authorities, the monitored 11 herbicides do not significantly affect the quality of the human environment. This work will provide scientific understanding of pesticide residues in drinking water standards in terms of its consistency with precautionary human health and environmental safety.

Solid-phase microextraction of sulfonylurea herbicides by using borate-reinforced multiple monolithic fibers.

Boron-nitrogen coordination is a useful interaction for use in the extraction of amino-nitrogen-containing compounds. A new monolithic adsorbent is described here that consisted of poly(acrylamidophenyl boronic acid/vinyl-3-octylimidazolium tetrafluroborate-co-divinylbenzene/ethylene dimethacrylate) polymer. It was synthesized with the aim to obtain a new kind of extraction phase for multiple monolith based fiber solid-phase microextraction of sulfonylurea herbicides. Results indicate that boron-nitrogen coordination interaction plays a key role in the efficient extraction. It is also found that soaking the sorbent in a borate solution further improves the enrichment performance. The preparation conditions and extraction parameters were optimized. Following extraction with the adsorbent, the sulfonylurea herbicides were submitted to quantitation by HPLC with DAD detection. The limits of detection are in the range of 9.0-18ng·L-1. The method was applied to monitor the herbicides in samples of tap, river and waste waters. Recoveries at spiking levels of 1.0, 10 and 100μg·L-1 are in the range of 70.1-108%, and the values for relative standard deviation are less than 10% for all analytes in all cases. Graphical abstract Schematic of the monolith-based adsorbent (MBA) on a multiple monolith based fiber (MMF) for use in solid-phase microextraction of sulfonylurea herbicides (SUs).

Halogen bond triggered aggregation induced emission in an iodinated cyanine dye for ultra sensitive detection of Ag nanoparticles in tap water and agricultural wastewater.

Aggregation induced emission (AIE) has emerged as a powerful method for sensing applications. Based on AIE triggered by halogen bond (XB) formation, an ultrasensitive and selective sensor for picomolar detection of Ag nanoparticles (Ag NPs) is reported. The dye (CyI) has an iodine atom in its skeleton which functions as a halogen bond acceptor, and aggregates on the Ag NP plasmonic surfaces as a halogen bond donor or forms halogen bonds with the vacant π orbitals of silver ions (Ag+). Formation of XB leads to fluorescence enhancement, which forms the basis of the Ag NPs or Ag+ sensor. The sensor response is linearly dependent on the Ag NP concentration over the range 1.0–8.2 pM with an LOD of 6.21 pM (σ = 3), while for Ag+ it was linear over the 1.0–10 μM range (LOD = 2.36 μM). The sensor shows a remarkable sensitivity for Ag NPs (pM), compared to that for Ag+ (μM). The sensor did not show any interference from different metal ions with 10-fold higher concentrations. This result indicates that the proposed sensor is inexpensive, simple, sensitive, and selective for the detection of Ag NPs in both tap and wastewater samples.

Detection of Legionella spp. in Public Hospitals Water Supplies in Lattakia-Syria

The present study was designed to evaluate the occurrence of Legionella spp. contamination in water taps and water tanks of public hospitals, Lattakia, Syria. It is the first study about Legionella in Syria. One hundred and thirty swabs from water taps and 26L of water from water tanks of seven hospitals were collected and detected for the presence of Legionella spp. by using GVPC, BCYE, BCY agar. The results were 49 of 130 (37.69%) water tap samples which were positive for Legionella spp, and most water tank samples were positive for Legionella spp.,too . In conclusion, Legionella spp. are present in aquatic hospitals environment of Lattakia, Syria, so hospital water systems may be the primary reservoirs for Legionnaires’ disease. Due to the serious risk of infections, it is better to make efforts to eliminate Legionella spp. in water supplies in Hospitals.

Identification of the Infection Source of an Outbreak of Mycobacterium Chelonae Keratitis After Laser in Situ Keratomileusis

Nontuberculous mycobacteria keratitis is a rare but challenging complication of laser in situ keratomileusis (LASIK). This study was conducted to determine the source(s) of infection in a cluster of cases of keratitis after LASIK and to describe this outbreak and patients' outcomes. In this retrospective, case series, single-center study, 86 patients were included who underwent LASIK or photorefractive keratectomy between December 2011 and February 2012. Corneal scrapes from the affected eyes, samples of tap and distilled water, water from the reservoir of the distilling equipment, steamer, and autoclave cassette; antiseptic and anesthetic solutions and surgical instrument imprints were cultivated in liquid and on solid media. Gram-negative bacteria and yeasts were identified using automated systems and mycobacteria by polymerase chain reaction-restriction enzyme analysis of the hsp65 gene (PRA-hsp65) and DNA sequencing. Mycobacterial isolates were typed by pulsed-field gel electrophoresis. The cases and outcomes are described. The main outcome measure was identification of the source(s) of the mycobacterial infections. Eight (15 eyes) of 86 patients (172 eyes) who underwent LASIK developed infections postoperatively; no patients who underwent photorefractive keratectomy developed infections. Mycobacterium chelonae was isolated from 4 eyes. The distilled water collected in the surgical facility contained the same M. chelonae strain isolated from the patients' eyes. Different gram-negative bacteria and yeasts were isolated from samples collected at the clinic but not from the patients' eyes. Tap water distilled locally in surgical facilities may be a source of infection after ocular surgery and its use should be avoided.

Paired-ion-based liquid phase microextraction for speciation of iron (Fe2+, Fe3+) followed by flame atomic absorption spectrometry

Paired-ion-based dispersive liquid–liquid microextraction as a simple, rapid and sensitive technique was used for speciation and determination of trace levels of iron (Fe2+, Fe3+) in different water samples. In this method, 4,5-dihydroxy-1,3-benzenedisulfonic acid (tiron) was used as the complexing agent to form anionic complex with Fe3+ at pH 3 followed by addition of cetyl pyridinium chloride (CPC) as a positive counter ion to form a hydrophobic complex of Fe(ІІІ)–tiron–CPC. At this pH, Fe2+ complex (Fe2+–tiron–CPC) is not stable and therefore remains in the sample solution. The total Fe was determined after the oxidation of Fe2+ to Fe3+ with concentrated hydrogen peroxide and the concentration of Fe2+ was determined from the difference between the concentration of total Fe and the Fe3+. Different parameters such as pH, concentration of tiron, concentration of CPC, type and volume of disperser and extraction solvent were investigated and optimum conditions were selected. Under the optimum conditions, the calibration curve was linear in the range of 20–300 µg L−1 of Fe3+ with a correlation coefficient of 0.9988. The relative standard deviation (%) based on six replicate analysis of 50 µg L−1 of Fe3+ was 3.5%. In order to check the accuracy of the proposed method, the certified reference material (CRM-TMDW) was analyzed and the determined value was in good agreement with certified value. The proposed method was successfully applied for determination of iron species in local tap, spring, river water and food samples.

Development of luminol-N-hydroxyphthalimide chemiluminescence system for highly selective and sensitive detection of superoxide dismutase, uric acid and Co2+

N-hydroxyphthalimide (NHPI), a well known reagent in organic synthesis and biochemical applications, has been developed as a stable and efficient chemiluminescence coreactant for the first time. It reacts with luminol much faster than N-hydroxysuccinimide, eliminating the need of a prereaction coil used in N-hydroxysuccinimide system. Without using prereaction coil, the chemiluminescence peak intensities of luminol-NHPI system are about 102 and 26 times greater than that of luminol-N-hydroxysuccinimide system and classical luminol-hydrogen peroxide system, respectively. The luminol-NHPI system achieves the highly sensitive detection of luminol (LOD = 70pM) and NHPI (LOD = 910nM). Based on their excellent quenching efficiencies, superoxide dismutase and uric acid are sensitively detected with LODs of 3ng/mL and 10pM, respectively. Co2+ is also detected a LOD of 30pM by its remarkable enhancing effect. Noteworthily, our method is at least 4 orders of magnitude more sensitive than previously reported uric acid detection methods, and can detect uric acid in human urine and Co2+ in tap and lake water real samples with excellent recoveries in the range of 96.35–102.70%. This luminol-NHPI system can be an important candidate for biochemical, clinical and environmental analysis.

PHYSICO-CHEMICAL AND BACTERIOLOGICAL COMPOSITION IN A METROPOLITAN DRINKING WATER DISTRIBUTION SYSTEM IN KATHMANDU

The study was concentrated on water quality appraisal in metropolitan drinking water distribution system in Kathmandu during 2011 to 2015 AD. The study covers 24 research areas from surface water sources, treatment plants, processing and water supply networks of public, private and community drinking water suppliers in the main city of Kathmandu valley. Water quality was analyzed under six physical, seventeen chemical and two bacteriological parameters. All tests were conducted in accordance with the procedures laid down in the Standard Methods. Total 320 samples collected during two years of periods. The physico-chemical parameters of tested water samples from sources, reservoirs and taps were found to be within the range of National Drinking Water Quality Standard (NDWQS). The turbidity and pH values for most of the tested water samples from sources, reservoirs and taps except for a few source and tap samples were found to be within the NDWQS guideline values. The chemical parameters values of majority of tested source water samples were below the maximum level. The values of iron, manganese, sodium and chloride content of some source samples were found higher than the maximum permissible level recommended by NDWQS and WHO guideline. Bacteriologically, larger proportion of water samples (sources, reservoirs and taps) were found to be unacceptable. The present study disclosed fecal contamination to be the major problem in drinking water from source to the distribution for city water supply systems in selected metropolitan areas. The physico-chemical qualities of water in most cases were within acceptable limit.Journal of Institute of Science and TechnologyVolume 22, Issue 1, July 2017, page: 159-164

Monitoring methods for Diaphorina citri Kuwayama (Hemiptera: Liviidae) on citrus groves with different insecticide application programmes

AbstractThe Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a major citrus pest that transmits the bacteria Candidatus Liberibacter asiaticus and Ca. L. americanus associated with huanglongbing (HLB) disease. Diaphorina citri population densities can affect the effectiveness of its monitoring and sampling methods. Thus, we compared different methods for adult D. citri monitoring in groves with and without insecticide application programmes. Four short‐term experiments were carried out, each one lasting four consecutive weeks. In these experiments, sticky cards with different colours (yellow, light green, green and dark green), sweep net, two suction device models, visual inspection and stem tap sampling were assessed. Two long‐term experiments were conducted for 4.5 and 5 years, in which only yellow sticky card and visual inspection for D. citri monitoring were assessed. For the short‐term experiments, psyllids were detected by all monitoring methods during all sampling periods in areas without chemical control. However, in areas with psyllid control via fortnightly and monthly applications of insecticides, only sticky cards, regardless of their colour, were able to detect the presence of D. citri. Similarly, for the long‐term experiments, yellow sticky cards were more effective than visual inspection for detecting and quantifying D. citri in all areas with or without insecticide application. Therefore, in areas where HLB is present and chemical control of psyllid is required, sticky cards are the most reliable option for monitoring D. citri.