Clean-up Effect Research Articles

Analytical Methods for the Determination of Pharmaceuticals and Personal Care Products in Solid and Liquid Environmental Matrices: A Review.

Among the various compounds regarded as emerging contaminants (ECs), pharmaceuticals and personal care products (PPCPs) are of particular concern. Their continuous release into the environment has a negative global impact on human life. This review summarizes the sources, occurrence, persistence, consequences of exposure, and toxicity of PPCPs, and evaluates the various analytical methods used in the identification and quantification of PPCPs in a variety of solid and liquid environmental matrices. The current techniques of choice for the analysis of PPCPs are state-of-the-art liquid chromatography coupled to mass spectrometry (LC-MS) or tandem mass spectrometry (LC-MS2). However, the complexity of the environmental matrices and the trace levels of micropollutants necessitate the use of advanced sample treatments before these instrumental analyses. Solid-phase extraction (SPE) with different sorbents is now the predominant method used for the extraction of PPCPs from environmental samples. This review also addresses the ongoing analytical method challenges, including sample clean-up and matrix effects, focusing on the occurrence, sample preparation, and analytical methods presently available for the determination of environmental residues of PPCPs. Continuous development of innovative analytical methods is essential for overcoming existing limitations and ensuring the consistency and diversity of analytical methods used in investigations of environmental multi-class compounds.

Imitation learning for aerobatic maneuvering in fixed-wing aircraft

This study focuses on the task of developing automated models for complex aerobatic aircraft maneuvers. The approach employed here utilizes Behavioral Cloning, a technique in which human pilots supply a series of sample maneuvers. These maneuvers serve as training data for a Machine Learning algorithm, enabling the system to generate control models for each maneuver. The optimal instances for each maneuver were chosen based on a set of objective evaluation criteria. By utilizing these selected sets of examples, resilient models were developed, capable of reproducing the maneuvers performed by the human pilots who supplied the examples. In certain instances, these models even exhibited superior performance compared to the pilots themselves, a phenomenon referred to as the “clean-up effect”. We also explore the application of transfer learning to adapt the developed controllers to various airplane models, revealing compelling evidence that transfer learning is effective for refining them for targeted aircraft. A comprehensive set of intricate maneuvers was executed through a meta-controller capable of orchestrating the fundamental maneuvers acquired through imitation. This undertaking yielded promising outcomes, demonstrating the proficiency of several Machine Learning models in successfully executing highly intricate aircraft maneuvers. This paper is an extended version of the previously ICCS 2023 published conference paper [1] .

Optimization, validation, and application of a liquid chromatography-tandem mass spectrometry method for the determination of 47 banned drug and related chemical residues in livestock urine using graphitized carboxyl multi-walled carbon nanotubes-based QuEChERS extraction

The establishment of an efficient method for the analysis of drug residues in animal urine facilitates the real-time monitoring of drugs used in the production of animal-derived food. A modified QuEChERS extraction–liquid chromatography-tandem mass spectrometry (LC–MS/MS) method was established for the determination of 47 banned drug and related chemical residues in livestock urine. The sample was extracted with acetonitrile by converting the acid-base environment. The sample cleanup effects of seven solid phase extraction cartridges and two EMR-Lipid products were compared, and three materials, including graphitized carboxyl multi-walled carbon nanotubes (MWCNTs), PSA, and C18, were selected as QuEChERS adsorbents from 24 materials. All analytes showed good linearity, with correlation coefficients (R2) greater than 0.9936. Low limits of quantification could be obtained, ranging from 0.2 to 5.5 ng/mL. The average recoveries at low, medium, and high spiked levels were in the range of 70.8–114.9 %, with intra-day precision ranging from 2.4 % to 11.2 % and inter-day precision ranging from 4.5 % to 16.1 %. Swine urine and bovine urine samples collected from different farms were effectively analyzed using the developed method, and metronidazole was detected in three swine urine samples.

Direct Analysis of Micro-biopsy Samples by Polarity Gradient Focusing Dip-and-Go Mass Spectrometry.

Direct analysis of micro-biopsy samples by mass spectrometry at single-cell level still faces major challenges. In this work, we developed a polarity gradient focusing dip-and-go strategy (PGF-Dip&Go) during induced electrospray ionization mass spectrometry (iESI-MS) analysis for real-time enrichment and spatial separation of compounds such as lipids, alkaloids, fatty amines, and drugs. Compared with direct iESI-MS analysis, enrichment of analytes (enrichment factor of 5.0-100.0) and spatial separation between different analytes were achieved. Owing to the enrichment effect and salt cleanup effect, the sensitivity of PGF-Dip&Go has been improved by 25-10,000 times compared with direct iESI-MS. PGF-Dip&Go has been successfully applied for the analysis of lipids in a 200 pL micro-biopsy section from an individual fish egg. Lysophosphatidylcholine (LPC), phosphatidylcholine (PC), and triglyceride (TG) were significantly enriched and separated according to their polarity differences, proving the potential of PGF-Dip&Go to be a noninvasive and powerful analytical tool for in situ analysis of complex small volumes in the future.

Determination of 20 Neonicotinoid Insecticides and Their Metabolites in Infant Foods by a Modified QuEChERS Method Combined with HPLC-MS/MS

A rapid, effective, and reliable method for the simultaneous detection of 20 neonicotinoids and their metabolites in infant foods has been developed using liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). To improve the accuracy and precision of the method, different extraction solvents, extraction methods, and adsorbents were evaluated to achieve a better recovery and clean-up effect. Under optimized conditions, the samples were extracted with acetic acid acidified acetonitrile/ethyl acetate by ultrasonication, and then were cleaned with reduced graphene oxide@Fe3O4 (rGO@Fe3O4) and primary and secondary amine (PSA) through a QuEChERS step. A matrix-matched calibration method was applied for quantification. Relative standard deviations were all <15% for intraday and interday precision. The values of limit of detection and limit of quantification were ranging from 0.02–0.35 μg·kg−1 and 0.1–1.0 μg·kg−1, respectively. The presented method was applied to the analysis of real samples.

Tuning intrinsic defects in ZnO films by controlling the vacuum annealing temperature: an experimental and theoretical approach

The control of native defects in the ZnO material is strongly important for a wide range of technological applications. In this paper, native defects are tuned via the post-thermal treatment of ZnO films in a high vacuum atmosphere. The microstructure of the as-grown ZnO film shows columnar growth and strongly polar-oriented grains along the c-plane (002). Also, the obtained results indicate that the as-grown film contains a high amount of intrinsic defects and strong lattice distortions. After the thermal annealing, the ZnO films display significant structural changes, which are reflected in their electrical, vibrational, and optical properties. Our findings suggest that these changes were attributed to the selective cleanup effect of the native defects and the partial deoxidation process mainly on the exposed particle surface (at high temperatures) tuned up by the thermal annealing temperature. According to DFT calculations, oxygen vacancies (V O ) show lower energy, followed by zinc vacancies (V Zn ) and oxygen interstitials (O i ) indicating that V O defect is the most stable in ZnO. That sequence of stability could suggest the sequence of the annihilation of those defects, which is in line with our experimental findings and also in agreement with literature results.

Measuring Vitamin D3 Metabolic Status, Comparison between Vitamin D Deficient and Sufficient Individuals

The main branch of vitamin D3 metabolism involves several hydroxylation reactions to obtain mono-, di- and trihydroxylated metabolites, including the circulating and active forms—25(OH)D3 and 1,25(OH)2D3, respectively. However, most clinical trials strictly target the determination of 25(OH)D3 to offer a view of the metabolic status of vitamin D3. Due to the growing interest in expanding this restricted view, we have developed a method for measuring vitamin D3 metabolism by determination of vitamin D3, 25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D3 and 1,24,25(OH)3D3 in human plasma. The method was based on SPE–LC–MS/MS with a large volume injection of human plasma (240 µL). Detection of di- and trihydroxymetabolites, found at the picogram per milliliter level, was attained by the combined action of high preconcentration and clean-up effects. The method allows obtaining information about ratios such as the known vitamin D metabolite ratio (24,25(OH)2D3/25(OH)D3), which can provide complementary views of vitamin D3 metabolic status. The method was applied to a cohort of obese patients and a reference cohort of healthy volunteers to find metabolic correlations between target analytes as well as differences as a function of vitamin D levels within and between cohorts.

Sequential combination of solid-phase sorbents to enhance the selectivity of organosulfur compounds for flavour analysis.

Flavour analysis remains challenging due to the range of selectivity demands, from the extraction of multiclass volatile compounds to the purification of low-concentration odourants (e.g. organosulfur compounds) amidst the high food matrix noise. In this study, the varying selectivities of solid-phase extraction (SPE) were leveraged upon for both multiclass and organosulfur compound analysis, using coffee as a model matrix. Polymeric SPE (Bond Elut ENV) was screened for significant (p<0.05) parameters affecting the recovery of 37 multiclass compounds, and the most influential parameters were optimised using a Box-Behnken design (elution solvent of 67:33 dichloromethane:ethyl acetate, loading pH of 4.8, and wash solvent of water). Following this, low-concentration organosulfur compounds which were challenging to detect in the complex coffee matrix were purified by adding a sequential SPE step for selectivity. A silver-based ligand-exchange SPE step (MetaSEP IC-Ag) was optimised for organosulfur compound recovery (wash solvents of dichloromethane and 43% acetonitrile in dichloromethane, elution solvent of 90mmol/L 1,4-dithiothreitol in dichloromethane). This was found to be complementary to polymeric SPE's matrix clean-up effect (which improved average organosulfur compound recovery by 5.45 times). Finally, both multiclass and sequential organosulfur extraction techniques demonstrated good performance in terms of reproducibility (1.0-9.0%) and linearity (R2>0.995), allowing for the detection of 3-mercapto-3-methylbutyl formate (3.741±0.387ng/mL) in coffee samples. In conclusion, this study highlights the potential for SPE to address a variety of complex flavour analysis demands with the appropriate selection and combination of solid-phases.

Determination of polybrominated diphenyl ethers in serum using isotope internal standard-gas chromatography-high resolution dual-focus magnetic mass spectrometry

建立了同位素内标-气相色谱-高分辨双聚焦磁质谱(GC-HRMS)同时测定人体血清中14种多溴联苯醚(PBDEs)的方法。血清样品解冻后,取0.5 mL与13C标记的内标物进行混合,加入甲醇沉淀样品中的蛋白质,比较了3种酸化条件下的去脂效果和回收率,结果显示硫酸去脂效果最好;使用液液萃取法提取样品中的目标物,比较了不同萃取溶剂对回收率的影响,结果显示以正己烷(6 mL)-甲基叔丁基醚(6 mL)作为萃取溶剂效果最好;提取液经固相萃取柱净化和洗脱,比较了不同固相萃取柱和洗脱溶剂的净化效果和回收率,结果显示采用硅胶柱净化和用正己烷-二氯甲烷(1:1, v/v)洗脱时效果最好;洗脱液经氮吹近干后用正己烷复溶,经GC-HRMS测定。目标物经Rtx-1614色谱柱(30 m×0.25 mm×0.1 μm)分离,电压选择离子检测(VSIR)模式测定。BDE-209在0.40~25 μg/L、其他13种多溴联苯醚在0.08~5 μg/L范围内线性关系良好,相关系数>0.995,方法检出限为0.01~0.51 μg/L,定量限为0.04~1.70 μg/L,加标回收率为75.5%~120.7%,日内精密度为3.8%~10.9%(n=6),日间精密度为4.2%~12.4%(n=6)。应用该方法对采集的某地区15份青少年血清样本进行检测,结果显示14种PBDEs中,BDE-47检出率为100%,其他组分均未检出,说明该人群存在一定的PBDEs暴露。与现有文献报道方法相比,本方法样本需求量少,灵敏度、准确度较高,可对人血清中包括BDE-209在内的14种PBDEs同时测定,有效提高检测效率。本方法的建立可为我国开展多溴联苯醚对人群健康的影响提供技术支撑。

Contamination status and health risk assessment of 31 mycotoxins in six edible and medicinal plants using a novel green defatting and depigmenting pretreatment coupled with LC-MS/MS

Mycotoxin contamination in edible and medicinal plants seeds is a potential toxicological concern for consumers. A novel, green and efficient defatting and de-pigment clean-up pretreatment was first developed for the simultaneous determination of 31 mycotoxins via freeze-out combined with solid-phase extraction. Combination of freeze-out and solid-phase extraction can achieve a double clean-up effect: defatting and depigmenting. The combination of the two can achieve a double clean-up effect. Excellent performance characteristics of method validation, inter- and intra-day precision (RSD <10%), and recovery (79.5–125.1%) were obtained, fulfilling the current legislation. Alarmingly, of the 117 batches of samples, more than 30% contained more than one kind of mycotoxin, 7.69% of which were detected at levels exceeding the limits defined in the European Pharmacopoeia, and four of which were detected at levels over five times higher than the maximum residue level. Furthermore, two risk assessment methods identified aflatoxins and Zearalenone as the most risk-inducing mycotoxins in these matrices. This is the first report on the contamination status and risk assessment of multi-mycotoxins in six edible and medicinal plant seeds (Coicis Semen, Semen Perisicae, Ziziphi Spinosae Semen, Cassiae Semen, malt and nutmeg). The presented method has unique advantages for evaluating multi-mycotoxin exposure in edible and medicinal plant seeds or other oil-rich matrices.

Mode Evolution of High Power Monolithic PM Fiber Amplifiers in the Presence of SRS Effect

In this work, mode evolution in the presence of stimulated Raman scattering (SRS) effect has been studied in a 2 kW polarization-maintained (PM) fiber amplifier. It proved that the SRS-induced mode distortion can be observed at 40 dB of signal to Raman noise ratio in a PM fiber amplifier, which is significantly lower than that in a non-PM system. By using mode decomposition (MD) method, the SRS-induced mode distortion has been analyzed quantitatively by decomposing the signal and the Raman light individually, and the signal mode evolution shows a dissimilar phenomenon compared with the SRS-induced transverse mode instability. The SRS effect in large mode area fiber lasers result in continuous excitation of signal high order modes (HOMs), which leads to the signal beam quality deterioration and the output power rollover. The power fraction of HOMs increases by 30&#x0025; with the Raman power ratio only being 1.67&#x0025; at the maximal output power, and the Raman Stokes light mainly exists in fundamental mode distribution, which can be attributed to the beam cleanup effect.

Wavelength-tunable mode-locked Yb-doped fiber laser based on nonlinear Kerr beam clean-up effect

We demonstrate a novel approach to achieve wavelength-tunable ultrashort pulses from an all-fiber mode-locked laser with a saturable absorber based on nonlinear Kerr beam clean-up effect. This saturable absorber was formed by a single-mode fiber spliced to a graded-index multimode fiber, and its tunable band-pass filter effect is studied by a numerical model. By adjusting the bending condition of graded-index multimode fiber, the laser could produce dissipative soliton pulses with their central wavelength tunable from1040 nm to 1063 nm. The pulse width of output laser could be compressed externally to 791 fs, and the signal to noise ratio of its radio frequency spectrum was measured to be 75.5 dB. This work provides a new idea for the design of wavelength-tunable mode-locked laser which can be used as an attractive light source in communication system.

A Comparison between a Two-Dimensional Liquid Chromatography System and a Traditional QuEChERS-LC Method with Regard to Matrix Removal and Matrix Effects in Pesticide Analysis Using Time-of-Flight Mass Spectrometry.

In this study, a fully automated two-dimensional liquid chromatography (2D-LC) system was used for the investigation of the clean-up effect and was compared with a traditional Quick Easy Cheap Effective Rugged and Safe (QuEChERS) liquid chromatography (LC) method. The focus of those investigations was on negative electrospray ionization (ESI) mode. For that purpose, matrix fingerprinting profiles were created. The results allowed a comparison of both methods regarding the estimation of the number and the polarity of detected compounds. Moreover, the results of the present study were compared with the results generated in positive ESI mode (presented in a previous study). Furthermore, the two methods were compared with regard to matrix effects (ME) of 321 analytes in positive ESI mode and 96 analytes in negative ESI mode. In general, fewer compounds could be detected when 2D-LC and/or the negative ESI mode was used. Especially, very polar compounds with m/z values >1000 could be separated and could not be detected anymore when 2D-LC was applied. Furthermore, the best results were obtained for most analytes when 2D-LC was used, although the extent of ME seemed to be higher with 2D-LC.

Seeing the beam cleanup effect in a high-power graded-index-fiber Raman amplifier based on mode decomposition.

Due to the beam cleanup effect, brightness enhancement (BE) can be achieved in a Raman fiber amplifier (RFA) based on multimode (MM) graded-index (GRIN) fiber. In this Letter, a novel, to the best of our knowledge, diagnostic tool of mode decomposition (MD) based on a stochastic parallel gradient descent algorithm is demonstrated to observe the beam cleanup effect in a GRIN-fiber-based RFA for the first time, to our knowledge. During output power boosting up to 405 W at 1130 nm, the output beam quality factor M2 improves from 3.45 to 2.88, with a BE factor of 10.5. The MD results based on the near-field beam profiles from RFA indicate that the modal weight of the fundamental mode increases from 74.5% to 87%, confirming that the fundamental mode dominates with higher Raman gain. Moreover, the beam quality is found to be limited by the existence of a higher-order (Laguerre-Gaussian) LG10 mode, which is insensitive to the beam cleanup effect. The correlation coefficient reaches over 0.98 for all MD results. Thus, the accuracy of the MD method is high enough to provide further valuable insight into the physics of spatiotemporal beam dynamics in MM GRIN fiber.

Simultaneous determination of 14 pesticide residues in tea by multi-plug filtration cleanup combined with LC-MS/MS

A combined method of multi-plug filtration cleanup (m-PFC) and liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) was established to simultaneously detect 14 pesticides in tea. The pesticides in water-soaked tea were extracted with acetonitrile. Cleanup of tea extract was performed using an m-PFC column packed with multiple cleanup materials: multi-walled carbon nano-tubes (MWCNTs), primary secondary amine (PSA) and anhydrous magnesium sulfate (MgSO4). The cleanup effect of the column was evaluated based on the rates of removal of tea components that interfered with pesticide recovery, henceforth referred to as interference components. Results showed that 14 pesticides had strong linearity in the range of 5–500 μg L−1 (r2 > 0.99). The quantitative limits were within the range of 3–50 μg kg−1. The average recoveries of 14 pesticides spiked into three different blank tea samples (green tea, black tea, oolong tea) at three levels of 0.05, 0.50 and 2.00 mg kg−1 were in the range of 62.3–108.8% with relative standard deviations of 0.2–13.6%. The m-PFC method can greatly improve the efficiency of sample pretreatment. Furthermore, this work provides methodological guidance on how to select cleanup materials and allocate their proportions.

Ultrasensitive determination of serotonin in human urine by a two dimensional capillary isotachophoresis-capillary zone electrophoresis hyphenated with tandem mass spectrometry

A two-dimensional capillary isotachophoresis-capillary zone electrophoresis method hyphenated with tandem mass spectrometry was developed and validated for ultrasensitive quantification of serotonin in real human urine samples. Under optimal conditions, the separation was achieved within 12 min (including on-line sample preparation) with the limit of detection of 34 pg mL−1 (due to a large volume sample injection, here 10 µL, and isotachophoretic preconcentration). This concentration limit represents the lowest value for serotonin in comparison to other previously published separation methods employing mass spectrometry detection and applied to urine matrices. Thanks to high orthogonality, on-line concentration and clean-up effects of this approach, other excellent validation parameters such as linearity (coefficient of determination > 0.99), inter-day and intra-day precision (relative standard deviations 3.5–12.2%), accuracy (relative errors within 99–109.4%), and recovery (96–102%) could be easily obtained too. To demonstrate applicability of the method, we monitored serotonin levels in various real samples (from a healthy volunteer and clinical ones). The determined levels, normalized on the creatinine concentrations, were in the range of 6.81–12.86 ng mmol−1 creatinine This advanced method is suggested for an effective, reliable, high sample throughput, and low cost routine clinical screening or targeted metabolomic studies of serotonin in urine samples.

Brightness enhancement in random Raman fiber laser based on a graded-index fiber with high-power multimode pumping

A brightness-enhanced random Raman fiber laser (RRFL) with maximum power of 306 W at 1120 nm is demonstrated. A half-open cavity is built based on a graded-index (GRIN) passive fiber and single high-reflective fiber Bragg grating written in it directly. Due to the beam cleanup effect in the GRIN fiber enhanced in the half-open RRFL cavity, the output beam quality factor M2 is improved from 9.15 (pump) to 1.76-2.35 (Stokes) depending on power, while the pump-Stokes brightness enhancement (BE) factor increases proportionally to output power reaching 6.1 at maximum. To the best of our knowledge, this is the highest power GRIN RRFL with BE.

Fe3O4 nanoparticles as matrix solid-phase dispersion extraction adsorbents for the analysis of thirty pesticides in vegetables by ultrahigh-performance liquid chromatography-tandem mass spectrometry

Herein we report the first example of Fe3O4 nanoparticles (FNPs) being used as single-matrix solid-phase dispersion (MSPD) adsorbents for the extraction of 30 representative pesticides from vegetables. This study was aimed at analyzing the extracted samples using ultrahigh-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Various condition parameters, such as the eluent, volume of the eluent, and amount of FNPs were optimized to achieve good sensitivity and precision for the elution and extraction of the analytes. The developed method was validated using matrices consisting of eight vegetables (lettuce, cucumber, carrot, tomato, pepper, shallot, Chinese flowering cabbage, and cabbage) spiked with 30 pesticides at concentrations of 0.01, 0.1, and 1.0 mg/kg. The recoveries of the 30 pesticides (organophosphorus, triazole, carbamate, nicotine, amide, and other different structures of pesticides) were in the range 71.0–110.8% (n = 5) (except those of prothioconazole and dinotefuran), with relative standard deviations lower than 13.5% in all the matrices under optimal conditions. The matrix effects were observed by comparing the slope of the matrix-matched standard calibration curve with that of the solvent. However, the matrix effects of the eight vegetables did not show evident regularities. For pepper, tomato, and shallot, a sizable number of pesticides (24, 21, and 21, respectively) showed suppressive matrix effects. On the other hand, for cucumber, Chinese flowering cabbage, and cabbage, a good number of pesticides (19, 18, and 15, respectively) showed negligible matrix effects. Furthermore, for carrot matrices, 21 pesticides showed a matrix enhancement effect. Excellent linearity was achieved at pesticide concentrations of 0.01–1.0 mg/L, and the limits of quantification (LOQ) for the developed method reached 0.01 mg/kg (except that for dinotefuran, which was 0.1 mg/kg), based on the spiked test. The developed method was successfully employed in the analysis of real samples in Nanning, China, and three pesticide residues (halosulfuron methyl, tebuconazole, and azoxystrobin) were commonly detected in vegetable samples. In the present study, a reliable method-validation performance and excellent cleanup effects were observed by using the modified MSPD method consisting of the FNPs in the cleanup step.

Diamond Raman laser: a promising high-beam-quality and low-thermal-effect laser

AbstractStimulated Raman-scattering-based lasers provide an effective way to achieve wavelength conversion. However, thermally induced beam degradation is a notorious obstacle to power scaling and it also limits the applicable range where high output beam quality is needed. Considerable research efforts have been devoted to developing Raman materials, with diamond being a promising candidate to acquire wavelength-versatile, high-power, and high-quality output beam owing to its excellent thermal properties, high Raman gain coefficient, and wide transmission range. The diamond Raman resonator is usually designed as an external-cavity pumped structure, which can easily eliminate the negative thermal effects of intracavity laser crystals. Diamond Raman converters also provide an approach to improve the beam quality owing to the Raman cleanup effect. This review outlines the research status of diamond Raman lasers, including beam quality optimization, Raman conversion, thermal effects, and prospects for future development directions.

Miniaturized Salting-Out Assisted Liquid-Liquid Extraction Combined with Disposable Pipette Extraction for Fast Sample Preparation of Neonicotinoid Pesticides in Bee Pollen.

As the main source of nutrients for the important pollinator honeybee, bee pollen is crucial for the health of the honeybee and the agro-ecosystem. In the present study, a new sample preparation procedure has been developed for the determination of neonicotinoid pesticides in bee pollen. The neonicotinoid pesticides were extracted using miniaturized salting-out assisted liquid-liquid extraction (mini-SALLE), followed by disposable pipette extraction (DPX) for the clean-up of analytes. Effects of DPX parameters on the clean-up performance were systematically investigated, including sorbent types (PSA, C18, and silica gel), mass of sorbent, loading modes, and elution conditions. In addition, the clean-up effect of classical dispersive solid-phase extraction (d-SPE) was compared with that of the DPX method. Results indicated that PSA-based DPX showed excellent clean-up ability for the high performance liquid chromatography (HPLC) analysis of neonicotinoid pesticides in bee pollen. The proposed DPX method was fully validated and demonstrated to provide the advantage of simple and rapid clean-up with low consumption of solvent. This is the first report of DPX method applied in bee pollen matrix, and would be valuable for the development of a fast sample preparation method for this challenging and important matrix.