Liquid Reagents Research Articles

Open-Source Portable Device for the Determination of Fluoride in Drinking Water.

The prolonged exposure to fluorides results in the development of several diseases, from dental fluorosis to crippling deformities of the spine and major joints. The population exposed to high fluoride concentration is located in developing countries where the assurance of water quality is difficult to perform. Addressing this challenge, an open-source system for the determination of fluoride in natural water was developed using the equilibrium between the red Fe-SCN complex and the colorless Fe-F. The reaction develops in cotton substrates to reduce the manipulation of liquid reagents and reduce the errors by nontrained operators. The system was optimized by image analysis and implemented in an open-source Arduino-based device and data was acquired through the serial port of a cell phone, which is also used as a power source, avoiding the use of a battery and reducing production costs. The device showed a detection limit of 0.7 mg L-1 and a linear range of up to 8 mg L-1. This extended detection limit makes the device useful for the application in regions where the fluoride concentration in drinking water is far higher than the United Nations limit (1.5 mg L-1), e.g., the United Republic of Tanzania, where the upper limit of F- was extended to 4 mg L-1 or in USA, where the Environmental Protection Agency established the Maximum Contaminant Level of F- in drinking water at 4 mg L-1. The method was tested with natural waters from the Arusha region in the northeast of Tanzania and validated against the results from ion chromatography showing a good correlation. The developed device exhibits chemical stability of 5 days, allowing it to be manufactured and distributed in local areas and, also, modified according to the requirements of the water composition due to Industry 4.0 concepts used in the design.

A breath of fresh air - the potential for COVID-19 breath diagnostics.

A breath of fresh air - the potential for COVID-19 breath diagnostics.

Chemical oxygen demand with APHA/AWWA/WEF 5220 D procedure for high concentration adapted to micro-volume

En este estudio se realizaron pruebas de linealidad y de precisión, para la determinación de la Demanda Química de Oxigeno (DQO) en agua, para una adaptación a micro-escala del método de reflujo cerrado a volumen pequeño para rango alto de APHA/AWWA/WEF. El trabajo tuvo como objetivo principal el demostrar que es posible obtener mediciones adecuadas al adaptar a micro-escala el método 5220 D de APHA/AWWA/WEF, referencia de amplio uso internacional para determinar la DQO en agua. El método adaptado a micro-escala requirió solamente de cambios en la concentración de cada sustancia en la solución de digestión, pero no así en la solución catalizadora de sulfato de plata, de manera tal que la concentración de cada una de estas sustancias en los tubos de digestión fuera casi igual a aquella correspondiente al método original (exceptuando la del sulfato de mercurio, que fue reducida deliberadamente). En la adaptación a micro-escala que aquí se presenta, los volúmenes dosificados de todos los reactivos líquidos fueron medidos mediante pipetas volumétricas clase A, mejorando la precisión en las mediciones con respecto al uso tanto de pipetas graduadas como de émbolo (necesarias para efectuar el método original). Los resultados obtenidos para la adaptación a micro-escala demostraron excelente ajuste lineal y precisión del sistema.

Genetic analysis with pyrosequencing using loop pipetting and a light dependent resistor.

DNA sequencing is among the most important techniques in biology to decipher the key genetic players of health and disease. The existing laboratory instruments for DNA sequencing are well established and reliable. However, these instruments are still out of reach of most laboratories in the world due to very high equipment and running costs and require trained personnel to keep them running. These instruments are also large and bulky making them unsuitable for analysis in remote settings away from laboratories. Here we describe a proof-of-concept of a DNA sequencing device LoopSeeq using a simple approach to address the said problems without minimizing the quality of results. The device was designed to perform pyrosequencing by iterative addition of dNTPs by contact dispensing through a loop pipette (loopette) and detection of chemiluminiscence with the cheapest sensor in the market, a light dependent resistor (LDR). Two small geared motors drive the moving parts in a controlled and coordinated manner with the help of a motor driver circuit, an Arduino Nano microcontroller and two small neodymium magnets. The real-time light intensity data from the LDR were transferred to a laptop computer for further analysis. Pyrosequencing was optimized using 55 nt self-primed oligo. In order to demonstrate the DNA sequencing ability with real samples, molecular genetic analysis was performed for a previously identified novel mutation from our lab in exon4 of the OCA2 gene. LoopSeeq successfully identified the homozygous normal (c.408-409_AA), homozygous mutant (c.408-409_delAA) and heterozygous carrier (c.408-409_AA/delAA) alleles in three individuals of a family affected with oculocutaneous albinism (OCA). Further, this can be implemented for molecular diagnostic applications for bacterial, viral or other pathogen detection and genotyping among different subtypes following some reports described earlier. A few drawbacks in the current implementation including the evaporation of liquid reagents, possible loopette contamination, etc. associated with use for longer times are also described along with suggestions to rectify these problems in future designs. With the described capabilities, the LoopSeeq device can be implemented in routine labs as well as in several real-world situations where conventional DNA sequencing instruments are unfeasible, for example, diagnostic testing at remote settings or at the point-of-care.

5,5-Dialkylluciferins are thermal stable substrates for bioluminescence-based detection systems.

Firefly luciferase-based ATP detection assays are frequently used as a sensitive, cost-efficient method for monitoring hygiene in many industrial settings. Solutions of detection reagent, containing a mixture of a substrate and luciferase enzyme that produces photons in the presence of ATP, are relatively unstable and maintain only a limited shelf life even under refrigerated conditions. It is therefore common for the individual performing a hygiene test to manually prepare fresh reagent at the time of monitoring. To simplify sample processing, a liquid detection reagent with improved thermal stability is needed. The engineered firefly luciferase, Ultra-Glo™, fulfills one aspect of this need and has been valuable for hygiene monitoring because of its high resistance to chemical and thermal inactivation. However, solutions containing both Ultra-Glo™ luciferase and its substrate luciferin gradually lose the ability to effectively detect ATP over time. We demonstrate here that dehydroluciferin, a prevalent oxidative breakdown product of luciferin, is a potent inhibitor of Ultra-Glo™ luciferase and that its formation in the detection reagent is responsible for the decreased ability to detect ATP. We subsequently found that dialkylation at the 5-position of luciferin (e.g., 5,5-dimethylluciferin) prevents degradation to dehydroluciferin and improves substrate thermostability in solution. However, since 5,5-dialkylluciferins are poorly utilized by Ultra-Glo™ luciferase as substrates, we used structural optimization of the luciferin dialkyl modification and protein engineering of Ultra-Glo™ to develop a luciferase/luciferin pair that shows improved total reagent stability in solution at ambient temperature. The results of our studies outline a novel luciferase/luciferin system that could serve as foundations for the next generation of bioluminescence ATP detection assays with desirable reagent stability.

Древесина как химическое сырье. История и современность. II. Анатомия древесины как фактор ее химической активности

The article is devoted to the history of studying the anatomy and morphology of woody plants, structural features of the basic anatomical elements inherent in deciduous and coniferous wood. Information is provided on the influence of the structural features of anatomical elements on the properties of fibrous semi-finished products and various types of paper and cardboard obtained from them. The influence of the wood structure of various species on the property of coals obtained as a result of their pyrolysis is shown. The features of the processes of penetration of liquid reagents into wood as a natural heterocapillary system are considered.

Polyphenylene as an Active Support for Ru-Catalyzed Hydrogenolysis of 5-Hydroxymethylfurfural.

Selective transformation of biomass feedstocks to platform molecules is a key pursuit for sustainable chemical production. Compared to petrochemical processes, biomass transformation requires the defunctionalization of highly polar molecules at relatively low temperatures. As a result, catalysts based on functional organic polymers may play a prominent role. Targeting the hydrogenolysis of the platform chemical 5-hydroxymethylfurfural (5-HMF), here, we design a polyphenylene (PPhen) framework with purely sp2-hybridized carbons that can isolate 5-HMF via π-π stacking, preventing hemiacetal and humin formation. With good swellability, the PPhen framework here has successfully supported and dispersed seven types of metal particles via a newly developed swelling-impregnation method, including Ru, Pt, Au, Fe, Co, Ni, and Cu. Ru/PPhen is studied for 5-HMF hydrogenolysis, achieving a 92% yield of 2,5-dimethylfuran (DMF) under mild conditions, outperforming the state-of-the-art catalysts reported in the literature. In addition, PPhen helps perform a solventless reaction, achieving direct 5-HMF to DMF conversion in the absence of any liquid solvent or reagent. This approach in designing support-reactant/solvent/metal interactions will play an important role in surface catalysis.

The Application of 4Å Molecular Sieves in Organic Chemical Syntheses: An Overview

AbstractIn the last two decades, considerable attention has been devoted to the use of 4Å molecular sieves (MS 4A) in organic chemical syntheses. Initially, they were applied as drying agents in order to dry gases, solvents and liquid reagents. Nowadays, there is a growing tendency to apply MS 4A as an additive, catalyst, co-catalyst or catalyst support in organic reactions. In this review, we aim to summarize the recent examples of organic syntheses promoted by MS 4A from 1997 to 2020. We hope to provide the reader with an overview of the potential of MS 4A in the field of organic synthesis.1 Introduction2 Application as an Additive3 Application as Catalyst4 Application as Co-catalyst5 Application as Support6 Conclusion

Abstract 4271: Standardized approach for monitoring plasma cell disorders

Abstract Multi-color flow cytometry using consensus surface markers (CD138, CD38, CD19, CD45, CD27, CD56, CD81, and CD117), intracellular kappa and lambda, as well as other auxiliary markers is routinely being used for the identification and characterization of plasma cells. Here, we describe the development of a modular 10-color plasma cell panel for immunophenotyping of the plasma cell compartment. The panel was developed as an 8-color dried backbone, which can be supplemented with 2 liquid (drop in) reagents. Lyophilized or dried reagent cocktails in a unit test format are known to drive workflow efficiency in clinical settings by eliminating the need for manual cocktailing (of reagents), and frequent batch to batch verification procedures. Longer shelf life and room temperature storage are additional appealing features for lyophilized and dried products. We have developed a dried-down 8-color plasma cell panel, which is manufactured in a single test-per-tube, ready to use format, and can be supplemented with liquid (drop in) reagents. The flexibility of being able to add 2 liquid reagents to the dried backbone provides the option of using intracellular kappa and lambda to examine clonality or using CD38-multi-epitope and/or anti-p63 (VS38c) reagent(s). The single test-per-tube format is ideally suited for MRD applications, where sample size is limited and there is a need for acquiring a large number of events for data analysis. Also, the dried reagent panel is comprised of multiple high performing polymer dyes, which are brighter than conventional dyes, and afford high resolution of the relevant cell populations. Furthermore, the dried reagent tubes have a long shelf life (12 months) and significantly enhance the workflow efficiency. Comparison of the liquid and dried versions of the 10-color plasma cell panel using peripheral blood from healthy donors (as well as control cell lines) showed similar staining patterns, comparable population statistics, and fluorochrome brightness. The dried plasma cell tube(s) were also tested on bone marrow samples from healthy and diseased subjects in conjugation with intracellular staining for kappa and lambda. Our results demonstrate that the 10-color plasma cell panel can be used for identification of the plasma cell compartment (based on CD38 & CD138 expression), assessment of aberrant marker expression (CD19, CD27, CD81, CD117, CD45, CD56) for the identification of normal and abnormal plasma cells, and examining clonality in multiple patient samples. Citation Format: Ulrika Johansson, Na Li, Suraj Saksena, Natalie Golts, Brent Gaylord. Standardized approach for monitoring plasma cell disorders [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4271.

A Disposable Multiplexed Chip for the Simultaneous Quantification of Key Parameters in Water Quality Monitoring.

On-site simultaneous quantification of multiple contaminants in a water body is challenging, especially for parameters requiring complicated chemical reactions to measure such as Chemical Oxygen Demand (COD), ammonia nitrogen, and phosphate. A novel disposable multiplexed microfluidic device has been developed herein that allows the quantitative detection of up to five parameters at once. Solid reagent rather than commonly used liquid reagent was used to ensure long shelf life, and a "flow to dissolve" mechanism was provided accordingly for the thorough dissolution and mixing of a solid reagent on chip. Samples from river water and industrial wastewater were tested using the microfluidic chip, showing less than 15% deviation from results acquired with the traditional standard method. The test time though was only 1/6 of that required by the traditional method. In addition, the feasibility of using a smartphone to collect the colorimetric signal was discussed, and a data analysis method was provided for quantification purposes. The combination of the multiplexed chip and smartphone imaging provides a convenient and practical way to obtain accurate information on the water quality within a short period of time without the use of any sophisticated instruments.

Reusable optofluidic point-of-care testing platform with lyophilized specific antibody for fluorescence detection of cholylglycine in serum.

A reusable optofluidic point-of-care testing platform (OPOCT) was successfully constructed through integrating evanescent wave fluorescence technology into an all-fiber-based optofluidic system. The compact design of the OPOCT allows it to be portable and suitable for on-site sensitive determination of biomarkers in serum without complicated and costly procedures. The sensitivity of 90.9pM for antibody determination is observed thanks to the high transmission efficiency of excitation light and fluorescence in the OPOCT. The affinity constant between cholylglycine (CG) and anti-CG antibody was quantified using this platform based on the proposed theory. Using the lyophilized fluorescence-labeled specific antibody and reusable fiber optic biosensor, the OPOCT is applied to the one-step sensitive determination of CG in serum, which eliminates the dearth associated with liquid reagent handling, disposable biosensors, and user intervention. A limit of detection of 0.025μg/mL for CG is obtained, which is far more than adequate for meeting diagnostic requirements. The matrix effect of serum samples on the evanescent wave-based optofluidic biosensor can be effectively reduced by simple dilution of serum samples. The performance of the OPOCT also compared favorably with that of a commercial turbidimetric inhibition immunoassay through analyzing multiple serum samples. This platform is ready to expand to measure any other biomarker by using its specific antibody. The simplicity, sensitivity, cost-effectiveness, and robustness of the OPOCT enable the early diagnosis of disease and making a timely clinical decision. Graphical abstract .

Rapid, efficient, and non-destructive purification of single-walled carbon nanotube films from metallic impurities by Joule heating

We demonstrate a simple and resource-efficient approach for rapid purification of single-walled carbon nanotube (SWCNT) films from catalyst impurities by Joule heating in a vacuum. As a result, the catalyst concentration decreases by a factor of 27 (from 17 to <1 wt%) after heating at 1600°C for 2 min. Moreover, the nanotube structure remains almost intact as the purified films show a high ratio of intensities of G to D bands of Raman spectrum IG/ID = 180. The technique perfectly fits for the devices based on free-standing carbon nanotube films such as protective membranes, infrared detectors, and sound generators. For purified SWCNT films, we show the signal-to-noise ratio for the bolometers to increase by a factor of 2.5 and 24% sound pressure gain for the air-coupled thermophones. The method can be easily extended to other applications, for instance, the SWCNT-based devices of limited liquid and harsh reagent tolerance like nanotube aerogels and drug delivery systems.

Anti-Microbial and Anti-Oxidant Activities of Ziziphus Spina Christi, Sudanese Medicinal Plant

This work is an anti-Microbial and anti-Oxidant activity of Ziziphus spina Christi based on four selected bacteria: Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. These species were collected and prepared in Sudan. The concentrations were carried out and compared with standard control sample, the suspension of anti-microbial activities have shown different results in Fagonia cretica. The anti-oxidant activity is the ability of bioactive compounds to prevent, delay and protect against oxidant of virus substrates such as DNA and lipid materials, both in living organisms (e. g. human) and in food products. The result showed an anti-oxidant activity based on standard liquid reagent [1].

Methods for Prevention of Winter Slippery

There are several methods for prevention of winter slippery on the roads – frictional, thermal, chemical, combined and structural. The friction method of combating slippery has found quite wide application. The method is based on increasing a wheel grip with iced road. Sand, slag, screening of stone materials and friction materials subjected to heating are used as a friction raw material. A thermal method is divided in conductive and convective according to a surface heating type in which a pavement is heated from below (electric heating) or from above (with a heat stream). Disadvantages of this method are its high cost when using thermal jets and harmful effects of high temperatures on a road surface. Nowadays a chemical method is considered as the most popular one to combat winter slippery. Treatment with solid or liquid reagents is provided in order to prevent slipping on the road surface or removing ice from it. The principle of their action is to lower a freezing temperature of the solution on the surface of the roadway. The fight against winter slippage is mainly carried out in a combined way by sprinkling roads with a sand and salt mixture. Currently, there is a need to completely or partially abandon the use of chlorides in the fight against winter slippery. In this case, the most promising direction is to prevent icing by creating coatings for roads with anti-icing properties that is introduction of anti-icing reagents in the composition of the road surface (construction method). This method makes it possible to increase cost of a finished road surface.

NUMERICAL RESEARCH OF QUALITY CHARACTERISTICS OF REAGENT DISTRIBUTION BY COMBINED ROAD MACHINE

From the theory of aerohydrodynamics it is known that the design of hydraulic nozzles and the modes of their operation determine the nature of the distribution of droplets in space and the efficiency of the process. The subject of the research is the characteristics of the distribution quality of the liquid reagent, namely, the speed of dropping of droplets from the disk and the radius of the treatment zone formed by flying droplets on the coating. The question of the dispersion of the spray torch of a low-viscosity liquid, its role in the formation of the basic kinematic characteristics of moving drops, is considered. The article provides a numerical calculation and analysis of the effect of the dispersion of droplets of a distributed liquid (reagent) on the rate of dropping of droplets from a rotating disk and on the radius of the coating treatment zone. For research, two values of nozzle nozzle openings and a wide range of variation in the diameters of reagent droplets were selected. Based on the mathematical models previously developed by the authors of the process of dropping droplets from the nozzle and the movement of droplets in the air, implemented as part of a software product, the velocity of dropping of droplets from the nozzle nozzle and the rate of dropping of droplets from the disk at a given pressure were calculated. A cycle of calculations of the radius of the coating treatment zone was carried out with varying work and geometric characteristics of hydraulic equipment, providing high-quality and cost-effective implementation of the anti-icing reagent distribution process.

Пути утилизации побочных продуктов при получении диоксида кремния из рисовой шелухи

The development of modern technologies for the use of rice husk (RH) as a raw material for the production of silicon dioxide (DC) is relevant. However, in the process of obtaining DC from RH, as a rule, solutions of acids and alkalis use. This makes it important to search for rational ways to regenerate these liquids and utilize exhaust gas emissions into the atmosphere in order to solve the problems of environmental protection. In the synthesis of DC based on RH, the following wastes are obtained: solid – carbon, liquid – solutions of hydrochloric acid and sodium oxide, exhaust gases. For utilization of the latter, it is effective to use the absorption purification method, based on the absorption by liquid reagents of toxic gases and vapors from their mixtures with air. The resulting sludge can be effectively used as a filler, in the manufacture of pavements (for example, asphalt). The resulting acidic wastewater can be used to neutralize alkaline solutions. After neutralization, in addition to discharging into the environment, these wastes can be used as chemical fertilizers (since they contain sodium chloride). Carbon can be used in the production of effective sorbents used, for example, to eliminate oil spills in environmental emergencies. Silicon dioxide obtained from rice husk is an effective filler of epoxy polymers, increasing their hardness, wear resistance and improving antifriction characteristics. It provides acceleration of the curing process and the formation of more denser cross linked structure of filled materials. The nature of the modifying action of silicon dioxide does not depend on the temperature of burning rice husk, which affects only the magnitude of the effects achieved.

A Performance-Optimized Multicolor Flow Cytometry Dried-Reagent Cocktail for Memory T-Cell Analysis

Abstract The reliance on flow cytometry for phenotypical and functional analyses of immune components in both research and clinical laboratories has increased the need flow cytometric assay standardization. Dried-down reagent cocktails pre-optimized with regards to fluorophore choice for each specificity as well as concentration of each conjugate can improve standardization. Use of a pre-optimized dried-down cocktail provides an efficient assay workflow which can minimize operator error in addition to offering enhanced reagent stability and reduced variability across instruments and sites. We developed a dried-down reagent cocktail for the identification and characterization of CD4+ and CD8+ T-cell memory and naïve subsets, including stem cell memory populations. The BD Horizon™ Dri Memory T cell panel contains optimized antibody-fluorophore conjugates against CD3, CD4, CD8, CD45RA, CD197, CD27 and CD95. Additional markers can be accommodated as drop-ins for a more comprehensive analysis. This cocktail was optimized for stain index in all channels of a red, blue, violet laser flow cytometer (BD FACSLyric™) in liquid format, then converted to dry format. The performance of the dried-down cocktail, with regards to MFI and % positivity of T-cell subsets, is comparable to that of its optimized liquid equivalents. Additionally, results are consistent across FACSLyric instruments and similarly when acquired on a BD LSRFortessa™. The comparable performance of the dried-down cocktail tube, along with the advantages offered by using a dried reagent cocktail, and the convenience of adding liquid drop-in reagents, reveal the BD Horizon Dri Memory T cell panel tube to be a valuable option for memory T-cell flow cytometry analysis.

Standardized Approach for Monitoring Plasma Cell Disorders

Abstract Multi-color flow cytometry using consensus surface markers (CD138, CD38, CD19, CD45, CD27, CD56, CD81, and CD117), intracellular kappa and lambda, as well as other auxiliary markers is routinely used for the identification and characterization of plasma cells. Here, we describe the development of a modular 10-color plasma cell panel for immunophenotyping of the plasma cell compartment. The panel was developed as an 8-color dried backbone, manufactured in a single test-per-tube, ready to use format. The dried backbone can be supplemented with liquid (drop in) reagents, which provides the flexibility of using intracellular kappa and lambda to examine clonality or using CD38-multi-epitope and/or anti-p63 (VS38c) reagent(s). The single test-per-tube format is ideally suited for MRD applications, where sample size is limited and acquisition of millions of events is needed for data analysis. In addition, the dried reagent tubes have a long shelf life (12 months at 20–25°C vs. 24 hours for liquid cocktails with multiple BV dyes in BSB buffer at 2–8°C). Furthermore, utilization of multiple high-performing polymer dyes in the panel affords high resolution of the relevant cell populations. The dried plasma cell tube(s) were tested on bone marrow samples from healthy and diseased subjects in conjunction with intracellular staining for kappa and lambda. Our results demonstrate that the 10-color plasma cell panel can be used for identification of the plasma cell compartment (based CD38 and CD138 expression), assessment of aberrant marker expression (CD19, CD27, CD81, CD117, CD45, and CD56) for the identification of normal and abnormal plasma cells, and examining clonality in multiple patient samples (Kappa and Lambda).

Visualization of Plasma-Induced Liquid Flow Using KI–Starch and PIV

The application of plasma jet interacting gel or liquid targets is widely researched and positive effects are obtained in biological experiments. To understand the working mechanism of plasma jet, the measurement of the spatial distribution of reactive oxygen species (ROS) is necessary. The authors have used potassium iodide (KI)–starch method, which uses reactions among KI, starch, and oxidative species, to visualize the distribution of ROS. Although our purpose focused on the 2-D distribution of ROS on the surfaces of liquid and agar regents, unexpected plasma-induced flow was also observed along the depth direction of the KI–starch liquid reagent. In this article, the plasma-induced flow generated by plasma jet was visualized with KI–starch, floating particle, and particle image velocimetry (PIV) methods, and the obtained results among the three observations were compared. The plasma-induced flow visualized by iodide–starch complexes in KI–starch method was similar to the flow of tracer particles in floating particle method. According to the analysis of PIV measurement, the velocity of the downstream was about 8 mm/s.

Separation and recovery of materials from the waste light emitting diode (LED) modules by solvent method

Nowadays, a large quantity of Light Emitting Diodes (LEDs) have been produced and updated with the development of optoelectronic industry. At the same time, many waste LEDs are discarded. However, there are many metals and non-metals in waste LEDs, which may cause secondary pollution and waste of resources if disposed improperly. In this study, solvent method was used to dissociate the waste LED modules and recycle resources. Firstly, the components of the waste LED modules were analyzed. The main component of the transparent plastic part, usually used as packaging materials, is cured epoxy resin, and the main component of the white plastic part as the skeleton of LED modules is a mixture of polyphenylene oxide (PPO) and polystyrene (PS). Then, eight organic solvents, [EMIM+]BF4− ion liquid and sodium hydroxide (NaOH) inorganic reagent were tried to separate a 40 × 40 mm2 waste LED module respectively. The results showed that only three organic solvents—dimethylformamide (DMF), dimethylacetamide (DMA), dimethyl-sulfoxide (DMSO) could dissociate the waste LED module very well. The used DMF solution was purified by rotary evaporation, and the regenerative DMF solution could be reused because its property has not changed. The solid residue obtained after rotary evaporating DMF was identified as polystyrene (PS). It was inferred that the waste LED module was dissociated through the DMF dissolving the PS of white plastic. In addition, the effect of DMF, DMA and DMSO dissociating the waste LED modules with the change of temperature was discussed. It was found that the choice of suitable solvent is a key for this method, and the heating temperature was also a very important factor. Finally, it was measured that the cured epoxy resin and the white plastic of the waste LED module accounted for about 31.4% (w/w) and 37.7% (w/w) respectively, which can be recycled. In short, the method not only separated completely the waste LED module and its each part was recycled easily, but the solvents can be reused. This study suggests a new route to recycle LEDs due to its environmentally friendly process, which may exert a significantly beneficial impact on our environment.