Separation Power Research Articles

Influence of ionization volume and sample gas flow rate on separation power in gas chromatography-ion mobility spectrometry

In this work, the influence of the sample gas flow rate and the ionization region volume of an ion mobility spectrometer (IMS) used as a detector in gas chromatography (GC) on GC-IMS peak shape has been investigated. Therefore, a drift tube IMS with a field-switching ion shutter, a defined ionization region volume and an ultra-violet radiation source was used. To identify the influence of the sample gas flow rate entering the ionization region (equals the GC carrier gas flow rate if no further make-up gas is used) and the ionization region volume on peak broadening and signal intensity, different sample volumes as they would elute from a GC were tested at a variety of sample gas flow rates at a given ionization region volume. The results clearly show that for low sample gas flow rates a depletion of sample molecules in the ionization region leads to a significant decrease in effective detector volume but also to reduced signal intensities. Therefore, for optimal performance of a GC-IMS, the optimal operating point of the GC should match the flow range, where the IMS provides the best compromise between signal-to-noise ratio and peak broadening.

Sensorless Control of Wound Field Synchronous Machine Drive Using Current Source-Based Modular Multilevel Converter

This paper proposes a wound field synchronous machine (WFSM) drive using a double star chopper cell (DSCC) based modular multilevel converter (MMC) for high power medium voltage variable speed applications. A controlled current source delivers power to this DSCC-MMC. This current source is derived using the field winding of WFSM and a 12-pulse full-controlled thyristor rectifier. The 12-pulse rectifier draws power from a three-phase grid and delivers power to the field winding and the DSCC-MMC. Thus, the field current of WFSM becomes the input dc current of the DSCC-MMC, and no separate power supply is required for the field winding of WFSM. The input current to the DSCC-MMC is kept constant at all operating speeds of the WFSM for a given value of torque to keep peak-peak voltage ripple constant across the submodule capacitor of the MMC. The field current is varied proportionately with the average torque to avoid the saturation of the machine at light load torque. This variation of field current is essential for the successful operation of DSCC-MMC. The small current ripple in the field current, caused by the 12-pulse thyristor rectifier, is utilized to extract the rotor speed information for sensorless operation of vector-controlled WFSM drive. Simulation results are presented in this paper to verify the proposed configuration and their control strategy at medium voltage. A hardware prototype has also been built in the laboratory to verify the same results experimentally at low voltage and low power.

Removal of Particulate Matter by a Non-Powered Brush Filter Using Electrostatic Forces.

In urban areas, a major source of harmful particulate matter is generated by vehicles. In particular, bus stops, where people often stay for public transportation, generate high concentrations of particulate matter compared to the general atmosphere. In this study, a non-powered type brush filter that generates electrostatic force without using a separate power source was developed to manage the concentration of particulate matter exposed at bus stops, and the removal performance of particulate matter was evaluated. The dust collection performance of the non-motorized brush filter varied by material, with particle removal efficiencies of 82.1 ± 3.4, 76.1 ± 4.7, and 73.7 ± 4.5% for horse hair, nylon, and stainless steel, respectively. In conditions without the fan running to see the effect of airflow, the particle removal efficiency was relatively low at 58.2 ± 8.4, 53.6 ± 9.2, and 58.0 ± 7.3%. Then, to check the dust collection performance according to the density, the number of brushes was increased to densify the density, and the horse hair, nylon, and stainless steel brush filters showed a maximum dust collection performance of 89.6 ± 2.2, 88.3 ± 3.2, and 82.1 ± 3.8%, respectively. To determine the replacement cycle of the non-powered brush filter, the particulate removal performance was initially 88.0 ± 3.2% when five horse hair brushes were used. Over time, particulate matter tended to gradually decrease, but after a period of time, particulate matter tended to increase again. The purpose of this study is to evaluate the particulate matter removal performance using a brush filter that generates electrostatic force without a separate power source. This study's brush filter is expected to solve the maintenance problems caused by the purchase and frequent replacement of expensive HEPA filters that occur with existing abatement devices, and the ozone problems caused by abatement devices that use high voltages.

LONG-LIFE PULSED VACUUM-ARC PLASMA SOURCE

The design of a pulsed vacuum-arc plasma source with an ignition system based on dielectric surface breakdown is presented and the principle of its operation is described. In the engineered plasma source, a four-section anode is used along with an equal number of arc ignition sections. Additionally, separate power supply circuits are employed for both the main pulsed arc discharge and the arc ignition circuit. Independent operation of each section of this device is carried out, essentially constituting a combination of four pulsed plasma sources in one, the coordinated functioning of which is ensured by the control system. Practical tests of the pulsed plasma source have revealed its advantages as followed: a fourfold increase in the ignition system life-time; achieving uniform depletion of the cathode working surface; and, under specific conditions, enhancing the productivity of the plasma source.

Three-dimensional simulation of gas flow for predicting the pressure and velocity profiles inside a gas centrifuge machine using the DSMC method

In this article, using the direct simulation Monte Carlo (DSMC) method, the gas flow inside the gas centrifuge was modeled simultaneously in the Knudsen and hydrodynamic zones. So that the three-dimensional (3D) simulation of gas centrifuge in the presence of all drivers inside the rotor, including feed, scoop, baffle, etc. was done. The results showed that, the feed is an important factor in creating and intensifying the axial flow formed in the rotor axis, and choke phenomenon occurs at the point of its entry into the rotor. It was further revealed that the amount of separation power obtained from the simulation (using the DSMC method) and the experimental has a difference of 4.3%, showing the agreement of the 3D simulations with reality.

Identification of variety-specific metabolites of basil by high performance thin layer chromatography-assisted metabolic profiling techniques

The technological advances of analytical instrumentation and techniques has laid the ground for the rapid expansion of metabolomics or in a wider sense, untargeted analysis applied to life sciences themes. However, the objective of identifying all existing metabolites within organisms remains a daunting challenge. All analytical techniques exhibit varying degrees of sensitivity and versatility for the detection of metabolites and none of the existing analytical platforms can be expected to be ideal for exhaustive chemical profiling. Planar liquid chromatography, and in particular, high performance thin layer chromatography (HPTLC), has been used for chemical profiling of natural products in conjunction with metabolomics. HPTLC has specific advantages which include its ability to generate reliable chemical fingerprinting data and facilitate preparative work for metabolite isolation during later stages of metabolomics analysis. In this study, we investigated the chemical profiles of four commercially available basil cultivars, namely Dolly, Emily, Keira, and Rosie. We used HPTLC as the primary analytical tool for the separation of basil cultivars based on detected metabolites, and then compared the results with those obtained with other analytical platforms. We identified the characteristic marker compounds of each basil cultivar from the HPTLC plates and validated their potential using LC-MS and GC-MS analyses as a metabolomics tool. Firstly, we compared the HPTLC data of the four cultivars, obtained with two systems that used silica gel 60 and two mobile phases composed of toluene-EtOAc (8:2, v/v) and EtOAc-formic acid-acetic acid-water (100:11:11:27, v/v), with 1H NMR data to evaluate their separation power. Despite providing lower resolution and detecting fewer compounds, the HPTLC separation power was comparable, and in some cases even better than that of 1H NMR. Additionally, we investigated the potential of HPTLC as a tool for chemical fingerprinting and demonstrated its suitability for preparative purposes that are essential for identifying metabolites in mixture analysis. Metabolites were easily isolated from sample mixtures, and identified with the assistance of GC-MS, LC-MS, and TLC-densitometry.. Several marker compounds were thus identified, including 2,4 di-tertbutylphenol, palmitic acid, hexadecanamide, 9-octadecenamide, squalene, hentriacontane, methyl 3-(3,5-ditert‑butyl‑4-hydroxyphenyl)propanoic acid, sagerinic acid, and cyanidin-3-O-sophoroside.

A promising modified polyvinyl chloride for adsorption of boron: Preparation, adsorption kinetics, isotherm, and thermodynamic studies

AbstractA new promising N‐methyl‐D‐glucamine modified polyvinyl chloride via methyl glycinate linker (PVC‐MG‐NMDG) was designed to extract boron from tourmaline ore from the Sikait area in the South Eastern Desert of Egypt, which assays 10.43% B2O3. Specifications for PVC‐MG‐NMDG composite were executed successfully utilizing sundry approaches, such as FT‐IR, XPS, GC–MS, TGA, BET, EDX, 13C‐NMR, 1H‐NMR, ICP‐OES, and XRD, which assure an acceptable synthesis of PVC‐MG‐NMDG. Optimized factors like pH, agitation time, primary boron concentration, composite dose, co‐ions, eluting agents, and temperature have been improved. At ambient temperature, pH 9, 10 min of agitation, and 0.0138 mol/L boron ions (150 ppm), the PVC‐MG‐NMDG composite has a 25 mg/g maximal uptake. The extraction‐distribution isotherm modeling suggests that the Langmuir model, with a theoretical value of 25.38 mg/g, more closely matches the practical value of 25 mg/g than the Freundlich model. The adsorption kinetics of boron ions by PVC‐MG‐NMDG were predicted with high accuracy using a pseudo‐second order kinetic model, yielding a theoretical retention capacity of 27.93 mg/g. The extraction process was predicted, as shown by thermodynamic calculations, exothermic, spontaneous, and optimal extraction at low temperature; the thermodynamic factors controlling ΔS (−0.04 kJ/mol), ΔH (−13.74 kJ/mol), and ∆G values rise from −1.82 kJ/mol at 298 K to −0.19 kJ/mol at 338 K. Boron ions can be eluted from the overloaded composite by 0.5 M H2SO4 with a 95% efficiency rate. It was established that PVC‐MG‐NMDG composite reveals a worthy separation factor to most co‐ions and gives a good separation power. Boric acid with a boron content of 17.23% and purity of 98.56% can be obtained through alkali fusion with NaOH flux and subsequent adsorption using a PVC‐MG‐NMDG composite.Highlights A New modified polyvinyl chloride (PVC‐MG‐NMDG) was successfully prepared. The characteristics of new composite were verified via different techniques. The new composite reached its maximum boron absorption of 25 mg/g at 25°C. The extraction as an exothermic, spontaneous process at low temperature. The new composite has been applied to a real sample of Sikait tourmaline ore.

Persulfate mediated single-channel bimodal self-checking light-assisted self-powered aptasensor for highly accurate assay

Developing multiple signals are needed for self-powered sensors to improve the detection accuracy. Herein we designed a novel dual-power-peak photofuel cell (PFC) based self-powered sensors with persulfate as an initiator. Persulfate expands photocatalytic redox reactions of PFC system, which enhanced separation of electrons and holes and more importantly, reduced the ohmic loss (ηohmic) efficiency and formed a second power peak for the first time. Such a self-powered sensor could self-check by using two separate power peaks in the same signal-readout window, greatly improving the accuracy compared with a single-peak-signal one. Moreover, the introduction of V2C MXene further accelerated the electron transfer and improved the photoelectric conversion efficiency. The aptamer was immobilized on the photoanode for the specific detection of the model analyte chloramphenicol and the reliable quantification was achieved via dual-power-peak density values from the single photoanode interface. Under optimum conditions, the linear range of this self-powered aptasensor was 0.5 pM to 3 nM, with a detection limit of 0.17 pM. As a result, a novel self-powered aptasensor was developed successfully based on the strategy of persulfate induced dual-power-peak, showing great promise in the development of multi-signal sensors with high accuracy and specificity.

Precipitation/Dissolution of Supersaturated V(III) Sulfate Electrolytes

Redox flow batteries (RFBs)-based storage systems have the unique feature of separate power generating and energy storage units that can be individually sized. RFBs can be used for days-long energy storage, but because of the low solubility of most ions and molecules in both aqueous and non-aqueous solvents,[1,2] scaling these RFB systems for days-long applications requires significant storage volume and floor area. Our team has been working on a new storage method that significantly increases the energy storage density while still maintaining the traditional flow battery design.[3] This method involves storing the reactants as both soluble ions and an undissolved solid form, only the liquid containing soluble ions is circulated through the batteries. To achieve this, a solid form of Vanadium salt must be precipitated within the storage tanks, necessitating a study on the precipitation and dissolution of various vanadium salts. Past work has been done by our group on the Vanadium (IV/V) solution,[4] we now focus on the Vanadium (II/III) solution. This presentation will discuss the production of Vanadium (III) sulfate salt electrolytes, and the precipitation rate of said salt at oversaturation.

Precipitation Mechanism of VOSO4 in Oversaturated Electrolytes of the Solid-Liquid Storage Method in Vanadium Redox Flow Batteries

Redox flow batteries (RFBs)-based storage systems have the unique feature of separate power generating and energy storage units that can be individually sized. RFBs can be used for days-long energy storage, but because of the low solubility of most ions and molecules in both aqueous and non-aqueous solvents,[1,2] scaling these RFB systems for days-long applications requires a lot of storage tanks and floor area. Our team has developed a new storage method that can significantly increase energy storage density while still maintaining the traditional flow battery design.[3] This method involves storing the reactants in both soluble ions and undissolved solid form, and only the liquid containing the soluble ions is circulated through the batteries. A larger than 4X improvement in storage energy density may be achieved with this strategy. The feasibility of this method was demonstrated in a hydrogen-vanadium (VI/V) RFB.[4] From the study, a major factor in achieving high performance with this hybrid storage system is the rates of the precipitation of the saturated electrolyte and dissolution of the solid precipitate. It was discovered that not all vanadium sulfate solids have precipitation rates fast enough to generate the active ions at the rate needed in the electrode reaction. Only the low crystallinity solid generated by rapid precipitation by the use of a suitable nucleation material was found to have the dissolution rate needed. This presentation will discuss the role of the molecule structures and the mechanism of the precipitation process in the formation of solids that have slow and fast dissolution rates.

All-transparent tandem photovoltaic-powered photodetector

Can electronics operate independently and invisibly in designated places? If yes, the user would not recognize the existence of devices and this can be applied to various applications. The device should be optically transparent and simultaneously achieve transparent electric power to satisfy this invisible freedom. Herein, we propose a dual transparent platform consisting of a broad-range translucent photodetector powered by an invisible photovoltaic unit. Transparent photovoltaic (TPV) has a NiO/TiO2 heterojunction for high optical transparency of 79.7% and can produce a maximum voltage of 0.6 V at an efficiency of 13.4%. A transparent broadband photodetector (TBD) that comprises Co3O4/ZnO has high optical transparency (70%) and provides a broad wavelength photodetection. The TBD can be tuned in the reverse bias mode along with the separate power unit (TPV), which significantly enhances the responsivity to 6.8 mA W−1. In contrast to the self-powered operation mode, the dual system (TBD and TPV power units) can actively control the bias voltage to the TBD, supplied from the TPV (0–0.6 V). TPV and TBD have an overall transparency of 56.4% and long-term stability to allow a high degree of freedom in transparent human electronics, ensuring visional transparency and an independent power supply.

Enhancing the Performance of a Renewable Energy System Using a Novel Predictive Control Method

The current study concerns improving the performance of a renewable energy system using systematically designed control algorithms. The performance of the system under study is evaluated under two operating scenarios: the first in which the system consists of only a wind-driven synchronous generator connected to the utility grid; in the second scenario, the generator is combined with a photo-voltaic solar system and a battery for supplying a load. Each system component is modeled and thoroughly described. To maximize the benefits of solar and wind energies, two separate maximum power point tracking procedures are adopted. Furthermore, to enhance the generator’s dynamics, a novel predictive control scheme is designed and validated by comparing its performance with traditional predictive control. The novel predictive controller utilized a simple and unique cost function to avoid the shortages of traditional predictive controllers. For standalone operation, an effective procedure is adopted to ensure the power balance between the generation, storage, and isolated load units. To evaluate the effectiveness of the designed controllers under different operating regimes, Matlab/Simulink is utilized for this task. The obtained results confirm the superiority of the novel predictive scheme used with the synchronous generator over the classic control approach for the two operating scenarios. This has been shown in the form of reduced ripples and reduced current harmonics. The obtained results are also confirming the validity of the adopted maximum power tracking strategies with solar panels and wind turbines as well. Furthermore, balanced power delivery is achieved thanks to the adopted management strategy for standalone operation, which enhances the overall system performance.

Verification of the Mode Decomposition Technique for Closely Distributed Modal Systems in the State Space Domain.

This study aims to propose and validate the state space mode decomposition technique for precise mode separation of non-classical damping systems and closely distributed modal systems. To assess the reliability and applicability of this technique, a 40-story building with a tuned mass damper is investigated, and acceleration responses measured by the building's health monitoring system are used for the verification of the technique. The mode separation results reveal that the separated modal power spectrum becomes distorted at neighboring natural frequency ranges when the performance index only considers the concentration of power spectral energy at the target natural frequency. However, by introducing an augmented performance index that includes a constraint condition to account for distortion, more accurate mode decomposition can be achieved.

Multidimensional chromatography in environmental analysis: Comprehensive two-dimensional liquid versus gas chromatography

Analysis of complex environmental matrices poses an extreme challenge for analytical chemists due to the vast number of known and unknown compounds, with very diverse chemical and physical properties. The need for a holistic characterisation of this complexity has sparked the development of effective tools to unravel the chemical composition of such environmental samples. Multidimensional chromatographic methods, namely comprehensive two-dimensional (2D) gas and liquid chromatography (GC × GC and LC × LC, respectively), coupled to different detection systems have emerged as powerful tools with the capability to address this challenge. While GC × GC has steadily gained popularity in environmental analysis, LC × LC is surprisingly less attractive in this research field. This critical review article explores the potential reasons why LC × LC is not the dominant technique used in environmental analysis as compared to GC × GC, while simultaneously highlighting the quite unique role of LC × LC for the target and untargeted analysis of complex environmental matrices. The possible combinations of stationary phases, the important role of the interfacing valve as the heart of an LC × LC assembly, the existing optimization strategies for improving the separation power in the 2D chromatographic space, and the need for user-friendly mathematical tools for multidimensional data handling are also discussed. Finally, a set of practical measures are suggested to increase the use and secure the success of LC × LC in environmental analysis.

A review of the zone broadening contributions in free-flow electrophoresis.

The broadening of analyte streams, as they migrate through a free-flow electrophoresis (FFE) channel, often limits the resolving power of FFE separations. Under laminar flow conditions, such zonal spreading occurs due to analyte diffusion perpendicular to the direction of streamflow and variations in the lateral distance electrokinetically migrated by the analyte molecules. Although some of the factors that give rise to these contributions are inherent to the FFE method, others originate from non-idealities in the system, such as Joule heating, pressure-driven crossflows, and a difference between the electrical conductivities of the sample stream and background electrolyte. The injection process can further increase the stream width in FFE separations but normally influencing all analyte zones to an equal extent. Recently, several experimental and theoretical works have been reported that thoroughly investigate the various contributions to stream variance in an FFE device for better understanding, and potentially minimizing their magnitudes. In this review article, we carefully examine the findings from these studies and discuss areas in which more work is needed to advance our comprehension of the zone broadening contributions in FFE assays.

Mechanism of Low-Frequency Oscillation When Electric Multiple Units Pass Neutral Zone, and Suppression Method

This article addresses the problem of the contact voltage increase caused by the low-frequency oscillation of the train-grid system in the phase-separation process of EMUs. The article establishes the EMU-contact line-traction substation model, reveals the mechanism of low-frequency oscillation, and ascertains the relationship between the phase angle when the pantograph leaves the line, and low-frequency oscillations. Methods to suppress overvoltage during the low-frequency oscillation are proposed. The research indicated that a significant voltage amplitude was observed in the neutral zone, when the phase angle of the pantograph to the contact line separation power supply fell within the range of 60–90° and 240–270°. The maximum voltage amplitude reached 69.75 kV, and there was an occurrence of low-frequency oscillation in the neutral zone, where electrical phase separation takes place. During this oscillation, the voltage of the contact network in the neutral zone mainly operated at one-third of the power frequency (16.7 Hz). However, after installing an RC suppression device in the neutral zone, when low-frequency oscillation occurred, the absolute value of the peak voltage dropped below 37 kV as soon as the EMU entered electric phase separation. Furthermore, compared to situations without a connected suppression device, there was nearly a 30% reduction in the absolute value of the peak voltage. The study provides a basis for the design of the neutral zone of the contact line, and the selection of high-voltage equipment for the EMU.

Allocation of carbon dioxide emissions to the by-products of combined heat and power plants: A methodological guidance

Cogeneration has higher efficiency than separate heat and power generation. Since both are generated in a single process, it is necessary to allocate the emissions to by-products for comparing their environmental performance. Numerous methods exist resulting in very different allocations. There is no consensus regarding the method choice. The main objective of this article is the development and implementation of an evaluation scheme allowing the choice of an appropriate method for specific applications. This scheme consists of nine criteria in the categories “Applicability”, “Environmental relevance”, and “Systematic approach” allowing a rating. The Finnish method performs best for a standard use case resulting in emission factors of 322 g CO2 / kWhel and 192 g CO2 / kWhth. Both are associated with less emissions per unit then the electricity and district heating mix of Germany in 2020 that were 375 g CO2 / kWhel and 270 g CO2 / kWhth. Therefore, cogeneration electricity and heat could contribute to climate protection in the short- to mid-term. The implementation of two sensitivity analyses shows that the location and country-specific emission factors can have a great influence on the results and the contribution to climate protection. Depending on use case and individual importance of certain criteria the Energy, the Exergy or the Greenhouse Gas method can be preferable. Each scored with one point less than the Finnish method. In contrast to existing publications, this study supports decision-makers in transparently selecting an appropriate allocation method when assessing the products of cogeneration by considering different criteria.

Towards a muon scattering tomography system for both low-Z and high-Z materials

Muon scattering tomography (MST) is a non-destructive technique to image various materials by utilizing cosmic ray muons as probes. A typical MST system with a two-fold track detectors is particularly effective in detecting high-Z materials (e.g. nuclear materials), but difficult to recognize low-Z materials (e.g. explosive materials). In this work, we present a concept of MST system to discriminate both low-Z and high-Z materials by extra measuring momentum of low-energy muons with a Cherenkov detector. A toy Monte Carlo simulation to describe detector responses and multiple scatterings of a muon tracking through materials is developed for statistical tests. Based on momentum-dependent track reconstruction and image reconstruction algorithm, we evaluate separation powers of different materials in the system. The results show that momentum measurement of low-energy muons and accurate track reconstruction can improve separation power of low-Z materials significantly. This may enable the MST system to detect both low-Z and high-Z materials with cosmic ray muons in the whole energy range.

Evaluation of additional electricity losses in electric networks using a meter

In this article, additional electricity losses are calculated using the voltage imbalance factor. There is also a method for predicting extra losses in the case of longitudinal and transverse asymmetry, as well as information on how to measure power quality indicators. It is suggested that home appliances be used to monitor a separate power system's power quality indicators. The findings of investigations on the condition of asymmetry conducted in operational low voltage electrical networks are presented, along with an illustration of how to calculate additional electricity losses in low-voltage networks. In this article for this purpose, the author developed a Malika device, which is fully capable to measure, store, analyze, and draw conclusions from the results of all electrical quality indicators.

Chromatographic reversed HPLC and TLC-densitometry methods for simultaneous determination of serdexmethylphenidate and dexmethylphenidate in presence of their degradation products—with computational assessment

Two Chromatographic methods have been established and optimized for simultaneous determination of serdexmethylphenidate (SER.DMP) and dexmethylphenidate (DMP) in the presence of their degradation products. The first method is a reversed phase high performance liquid chromatography with diode array detection (HPLC–DAD). Isocratic separation was carried out on Waters X-bridge Shield RP18 column (150×3.9×5 μm particle size) using a mixture of 5 mM phosphate buffer (pH 5.5): acetonitrile (40:60, v/v) as a mobile phase, flow rate 1 mL/min and detection at 220 nm. The second method is a thin-layer chromatography (TLC)—densitometry method using methanol: chloroform (70:30, v/v) as a mobile phase and UV scanning at 220 nm. In HPLC method, the linearity range of SER.DMP was (2.5–25 μg/mL); with LOD (0.051 μg/mL) and LOQ (0.165 μg/mL) while for DMP was (2.5–25 μg/mL); with LOD and LOQ of (0.098 μg/mL) and (0.186 μg/mL), respectively. For TLC method the sensitivity range of SER.DMP was (5–25 μg/mL), LOD was (0.184 μg/spot), while LOQ was (0.202 μg/ spot) whereas for DMP the sensitivity range was (5–25 μg/mL) with LOD of (0.115 μg/ spot) and LOQ of (0.237 μg/ spot), respectively. SER.DMP was found to be equally labile to acidic and alkaline hydrolysis, whereas DMP was sensitive to acidic hydrolysis only. Both drugs were successfully determined in presence of acidic and basic degradants by the two developed methods (stability indicating assay method). Chromatographic separation of the degradation products was carried out on TLC aluminum silica plates 60 F254, as a stationary phase, using methanol: dichloroethane: acetonitrile (60:20:20 v/v), as a mobile phase. The degradation pathway was confirmed using TLC, IR, 1H-NMR and mass spectroscopy; moreover, the separation power was correlated to the computational results by applying molecular dynamic simulation. The developed methods were validated according to the International Conference on Harmonization (ICH) guidelines demonstrating good accuracy and precision. They were successfully applied for quantitation of SER.DMP and DMP in pure and capsule forms. The results were statistically compared with those obtained by the reported method in terms of accuracy, precision and robustness, and no significant difference was found.