Use Of Differential Scanning Calorimetry Research Articles

Use of differential scanning calorimetry as a rapid, effective in-process check method for impurity quantitation of an early clinical batch of Giredestrant (GDC-9545)

Giredestrant (GDC-9545) is a selective estrogen receptor degrader (SERD) that was developed for treatment of ER+/HER2− metastatic breast cancer. An anhydrous crystalline tartrate salt was identified as the solid form suitable for clinical development. An early clinical batch of the active pharmaceutical ingredient (API)/drug substance failed to pass the GMP purity specifications owing to the presence of a substantial amount of high molecular weight impurities (oligomers), as determined by size exclusion chromatography. Several trial rework batches were manufactured using various re-slurry and recrystallization conditions to purge impurities in the drug substance to adhere to purity specifications. Based on the melting point depression of the API in presence of oligomers in these rework batches, a differential scanning calorimetry method was developed to quantify impurity content as a function of melting point onset of the API. This thermal analysis method was used as a surrogate for chromatography as a rapid, effective in-process check method for impurity quantitation to enable the timely release of the final reworked clinical batch. Post release, the % w/w oligomer value determined by calorimetry was in excellent agreement to that obtained by size exclusion chromatography.

Innovative approach for quantitative determination of ingested microplastics by Daphnia magna: use of differential scanning calorimetry and thermogravimetry

AbstractDue to the serious environmental impacts of plastic pollution, some conventional plastics have been replaced with biodegradable alternatives. However, these biodegradable options can also fragment and form microplastics, which can be ingested by and harm various biota. The standard methods for quantifying ingested microplastics involve digestion of the gut or the whole organism using acidic, alkaline, or oxidative processes. However, these aggressive methods may destroy biodegradable microplastics, leading to erroneous results. Therefore, in this study, we employed thermal analysis methods, specifically differential scanning calorimetry (DSC) and thermogravimetry (TG), to quantify the ingestion of poly-3-hydroxybutyrate (P3HB), a biodegradable microplastic, by the freshwater crustacean, Daphnia magna. During chronic experiments, we analysed organisms exposed to P3HB with sizes smaller than 125 and 63 μm, at concentrations ranging from 1.56–25 mg L−1. DSC identified an endothermic peak associated with the melting of semicrystalline P3HB, and its enthalpies were utilised to compute the number/mass of P3HB ingested by D. magna. Notably, shifts in melting points suggested that higher concentrations induced particle agglomeration, and these agglomerates could not penetrate deeply into the organism. The TG approach involved subtracting the mass loss between 200 and 400 °C in D. magna specimens exposed to P3HB suspensions from controls without P3HB exposure. Both methods provided comparable data, revealing that, depending on particle size, individual D. magna ingested up to 10% of their body mass. Our findings indicate that both methods effectively detect P3HB (and potentially other plastic fragments), with DSC demonstrating better sensitivity. While the suggested approach did not enable us to calculate the level of determination or quantification, we were able to demonstrate that DSC can detect P3HB in only one specimen of D. magna exposed to the lowest suspension concentration. This indicates that D. magna exposed to the 63 μm fraction ingested approximately 3 μg of P3HB, whereas those exposed to the 125 μm P3HB ingested around 4 μg of P3HB. The introduced methods expand the possibilities for detecting ingested microplastics and probably also nanoplastics, in zooplankton and possibly also other species.

EFFECT OF HEATING AND COOLING ON 6CB LIQUID CRYSTAL USING DSC TECHNIQUE

In this research, details of the heating and cooling of the liquid crystal (LC) 4-cyano-4'-hexylbiphenyl (6CB) were collected through the use of Differential Scanning Calorimetry (DSC), and then analyzed with Logger Pro. The sample of 6CB was heated from -40 °C to 80 °C and then cooled to -40 °C again at a constant rate of 20 °C/min. DSC provided data for the time, temperature, and heat flow, which was used to calculate thermal speed, acceleration, and jerk, as well as the specific heat capacity at each point. Graphs of this data contain endothermic and exothermic peaks that indicate phase transitions, revealing information such as the enthalpy of the peak and the nematic range. One focus of this study was to compare 6CB to other liquid crystals that are part of the n-alkyl-cyanobiphenyl (nCB) family to see if the difference in tail length affects the behavior of the liquid crystal. Results show that 6CB may be of interest as an alternative to other liquid crystals for liquid crystal displays (LCD).

Structure–energy relationship of food materials using differential scanning calorimetry

AbstractThe use of differential scanning calorimetry (DSC) in the food authentication and process‐chain traceability has raised significant amelioration in terms of structure and stability of some structured foods. In this review article DSC is used to raise other quantitative energy parameters related to structural reconformation and variation in the intra‐molecular dimension of studied materials. These properties are explained by the respective energy models involving (1) quantum energy, (2) quantum mass, and (3) quantum velocity. These models parameters are explored as well as on from enthalpy, entropy, heat capacity, and Gibbs free energy of transition in determining the nucleation energy relevant to crystallization and polymorphic transformation of some studied food‐materials.Practical ApplicationDifferential scanning calorimetry is remaining the powerful thermoanalytical tool used in studying the mechanism of crystallization, polymorphism, and structural reconformation of biological matters. The expression of energetic parameters on from enthalpy, entropy, heat capacity, and Gibbs free energy of transition help in determining the nucleation energy whether is stable or in the meta‐static forms. In addition these energy parameters are the key elements in understanding whether the food materials undergoing denaturation, unfolding or reversible folding, meaning that DSC is able in determining the status of food materials whether is stable or instable as well as the texture whether is soft, grainy, or coarse and also the polymorphic forms of the crystals and stability of the emulsions. Thus, gathering information on the thermal analysis using DSC helped in establishing some model correlation between energy and structure in association with the chemical composition changes of some model of oils and fats.

Experimental Studies on the Thermal Properties and Decomposition Course of a Novel Class of Heterocyclic Anticancer Drug Candidates

The experimental studies on the thermal properties and decomposition course of a novel class of potential anticancer drugs (1-5) containing in their heterobicyclic structures the asymmetrical triazine template were performed with the use of differential scanning calorimetry (DSC) and simultaneous thermogravimetry/differential scanning calorimetry (TG/DTG/DSC) coupled online with Fourier transform infrared spectroscopy (FTIR) and quadrupole mass spectrometry (QMS) in inert and oxidizing conditions. All the compounds were thermally characterized in detail for the first time in this article. The DSC studies proved that the melting points of the tested compounds depended on the position and type of the substituent at the phenyl moiety, whereas they did not depend on the furnace atmosphere. All the tested polynitrogenated heterocycles proved to be molecules with high thermal stability in both atmospheres, and most of them (1, 3-5) were more stable in oxidizing conditions, which indicated the formation of a more thermally stable form of the compounds when interacting with oxygen. The simultaneous TG/FTIR/QMS analyses confirmed that their pyrolysis process occurred in one main stage resulting in the emission of volatiles such as NH3, HNCO, HCN, CO, CO2, H2O, NO2, aromatic amine derivatives, alkenes (for compounds 1-5), and HCl (for the compound 5). On the other hand, the oxidative decomposition process was more complicated and proceeded in two main stages leading to the emission of NH3, CO2, CO, HCN, HNCO, H2O, some aromatics (for compounds 1-5), HCl (for compounds 3-5) as well as the additional volatiles such as N2, NO2, NH2OH, and (CN)2. The type of the formed volatiles indicated that the decomposition process of the studied heterocycles under the influence of heating was initiated by the radical mechanism. Their decomposition was related to the symmetric cleavage of C-N and C-C bonds (inert conditions) and additional reaction of the volatiles and residues with oxygen (oxidizing conditions).

Enabling Efficient Design of Biological Formulations Through Advanced Characterization.

The present review summarizes the use of differential scanning calorimetry (DSC) and scattering techniques in the context of protein formulation design and characterization. The scattering techniques include wide angle X-ray diffractometry (XRD), small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS). While DSC is valuable for understanding thermal behavior of the excipients, XRD provides critical information about physical state of solutes during freezing, annealing and in the final lyophile. However, as these techniques lack the sensitivity to detect biomolecule-related transitions, complementary characterization techniques such as small-angle scattering can provide valuable insights.

Essence of Thermal Analysis to Assess Biodiesel Combustion Performance

The combustion phenomena are always complex in nature due to the involvement of complex series and parallel reactions. There are various methods that are involved in analyzing combustion phenomena. Viscosity is the first and foremost factor that acts as the DNA of fuel. By evaluating the viscosity, it is possible initially to understand the combustion phenomena. Thermophysical and transport properties are helpful during the intensification of the combustion process. Combustion experiments are economically infeasible and time-consuming processes. Combustion simulations demand excellent computational facilities with detailed knowledge of chemical kinetics. So far, the majority of researchers have focused on analyzing coal combustion phenomena, whereas less work has been carried out on liquid fuels, especially biodiesel combustion analysis. Traditional engine testing provides only performance parameters, and it fails to have oversight of the thermodynamic aspects. The application of thermal analysis methods in combustion research is useful in the design, modeling, and operation of the systems. Such investigations are carried out extensively in the combustor, engine, and process industries. The use of differential scanning calorimetry (DSC) and thermogravimetry (TG) to assess the properties of biofuels has been attracting researchers in recent years. The main objective of this paper is to discuss the application of TGA and DSC to analyze heat flow, enthalpy, thermal stability, and combustion indexes. Moreover, this paper reviews some of the other aspects of the kinetics of combustion, transport properties’ evaluation, and combustion simulations for biodiesels and their blends. TG curves indicate two phases of decomposition for diesel and three phases for biofuel. The B-20 blend’s (20% biodiesel and 80% diesel) performance was found to be similar to that of diesel with the combustion index and intensity of combustion nearly comparable with diesel. It is thermally more stable with a high offset temperature, confirming a longer combustion duration. A case study reported in this work showed diesel and B20 JOME degradation start from 40 °C, whereas jatropha oil methyl ester (JOME) degradation starts from 140 °C. JOME presents more decomposition steps with high decomposition temperatures, indicative of more stable compound formation due to the oxidation process. The peak temperature of combustion for diesel, JOME, and B20 JOME are 250.4 °C, 292.1 °C, and 266.5 °C, respectively. The ignition index for the B-20 blend is 73.73% more than that of diesel. The combustion index for the B20 blend is 37.81% higher than diesel. The B20 blend exhibits high enthalpy, better thermal stability, and a reduced peak temperature of combustion with an improved combustion index and intensity of combustion nearly comparable to diesel.

Honey adulteration detection based on composition and differential scanning calorimetry (DSC) parameters

One of the most important issues regarding the quality of honey is its adulteration through the addition of non-allowed substances. For this reason, this study aimed at assessing the usefulness of DSC combined with sugar composition analysis for the detection of sunflower honey adulteration with five types of syrups (agave, maple, rice, corn, and inverted sugar syrup) in percentages of 5, 10 and 20%. Sunflower honey and the syrup samples showed differences in the fructose and glucose content. For these two sugars, an overall reduction of the concentration was observed following adulteration; a greater difference was observed when the adulteration was made with corn syrup, maple syrup or rice syrup. Authentic honey showed one or two thermal transitions (glass transition and a second transition), and notable different DSC parameters by comparison to syrup samples. The addition of syrup and the increase of the proportion of syrup added determined a slight decrease of the glass transition temperature of honey. The sugar composition and the DSC parameters coupled with PLSR were successful in predicting the percentage of adulteration agent added into honey.

Enhancing Photoelectric Powder Deposition of Polymers by Charge Control Substances.

Charge control substances (CCS) as additives for polymer powders are investigated to make polymer powders suitable for the electrophotographic powder deposition in powder-based additive manufacturing. The use of CCS unifies the occurring charge of a powder, which is crucial for this novel deposition method. Therefore, commercially available polymer powder is functionalized via dry coating in a shaker mixer with two different CCS and analyzed afterwards. The flowability and the degree of coverage of additives on the surface are used to evaluate the coating process. The thermal properties are analyzed by use of differential scanning calorimetry. Most important, the influence of the CCS on the powder charge is shown by measurements of the electrostatic surface potential at first and the powder deposition itself is performed and analyzed with selected formulations afterwards to show the potential of this method. Finally, tensile strength specimens are produced with the conventional deposition method in order to show the usability of the CCS for current machines.

Thermal wear of epoxy composite modified with rutile titanium dioxide

Epoxy composites have been widely used to properly bond the carbon fiber reinforced polymers (CFRPs) applied in the structural strengthening of reinforced concrete members. However, due to the thermal wear the epoxy composite loses its mechanical properties when exposed to sunlight heating, especially at temperatures above the glass transition temperature (Tg). Therefore, this study discusses the scientific phenomena of thermal wear of epoxy composite modified with 10, 20 and 30% of titanium dioxide (TiO2). The specific heat capacity (c) and Tg of the epoxy composites were calculated from heat flow results obtained with the use of differential scanning calorimetry (DSC). The novelty of the article includes the presentation of the influence of sunlight energy on the thermal wear of epoxy composites modified with TiO2 particles, which occurs at temeperatures higher than Tg. This work also presents the methodology for calculating the energy and the heating time of epoxy resins.

The Utility of Differential Scanning Calorimetry Curves of Blood Plasma for Diagnosis, Subtype Differentiation and Predicted Survival in Lung Cancer.

Simple SummaryLung cancer (LC) is the most common malignancy and the leading cause of cancer deaths in the world. Limitations of current screening approaches, such as substantial cost, radiation exposure, and high-false positive rates as well as increasing numbers of LC diagnoses in people without known risk factors, indicate the need for the development of new screening strategies. The aim of our study was to evaluate the utility of differential scanning calorimetry (DSC) for LC patients’ diagnosis. We found that DSC curves could be useful in differentiation of LC patients from control individuals and some changes were subtype or/and stage-dependent. Moreover, some DSC curve features correlated with patients’ overall/progression-free survival. Although the utility of the DSC technique still needs to be confirmed in a clinical setting, with further optimization and development of the classification method, this technique could provide an accurate, non-invasive, radiation-free strategy for LC screening and diagnosis.Early detection of lung cancer (LC) significantly increases the likelihood of successful treatment and improves LC survival rates. Currently, screening (mainly low-dose CT scans) is recommended for individuals at high risk. However, the recent increase in the number of LC cases unrelated to the well-known risk factors, and the high false-positive rate of low-dose CT, indicate a need to develop new, non-invasive methods for LC detection. Therefore, we evaluated the use of differential scanning calorimetry (DSC) for LC patients’ diagnosis and predicted survival. Additionally, by applying mass spectrometry, we investigated whether changes in O- and N-glycosylation of plasma proteins could be an underlying mechanism responsible for observed differences in DSC curves of LC and control subjects. Our results indicate selected DSC curve features could be useful for differentiation of LC patients from controls with some capable of distinction between subtypes and stages of LC. DSC curve features also correlate with LC patients’ overall/progression free survival. Moreover, the development of classification models combining patients’ DSC curves with selected plasma protein glycosylation levels that changed in the presence of LC could improve the sensitivity and specificity of the detection of LC. With further optimization and development of the classification method, DSC could provide an accurate, non-invasive, radiation-free strategy for LC screening and diagnosis.

Thermal and Kinetic Properties of Brazilian Coffea Arabica Beans

The chemical composition of green coffee beans depends on the number of parameters, such as coffee cherry processing methods, used. The quality of roasted coffee is related to the certain substances that developed during the roasting process and that are responsible for the organoleptic properties. The main objective of this study was an investigation of the thermal behaviour and the fatty acids profile of green and roasted Brazilian Santos coffee beans. The glass transition temperature was measured using modulated differential scanning calorimetry (MDSC). The thermal behaviour of coffee samples was evaluated by means of thermogravimetry (TG) and first derivative thermogravimetry (DTG). The oxidative stability and kinetic parameters were characterized with the use of differential scanning calorimetry (DSC). According to the TG and DTG curves, coffee samples showed different behaviour of thermal degradation in the atmosphere of oxygen and nitrogen. Our research shows that the thermal properties and fatty acids profile did not change during the roasting process.

New Liquid Crystal Assemblies Based on Cyano-Hydrogen Bonding Interactions.

A new selection of supramolecular liquid crystal complexes based on complementary molecules formed via hydrogen-bonding interactions is reported. All prepared complexes were prepared from 4-n-alkoxybenzoic acid (An) and N-4-cyanobenzylidene-4-n-(hexyloxy)benzenamine (I). FT-IR, temperature gradient NMR, Mass Spectrometer and Chromatography spectroscopy were carried out to confirm the -CN and −COOH H-bonded complexation by observing their Fermi-bands and the effects of the 1H-NMR signals as well as its elution signal from HPLC. Moreover, binary phase diagrams were established for further confirmation. All formed complexes (I/An) were studied by the use of differential scanning calorimetry and their phase properties were validated through the use of polarized optical microscopy Results of mesomorphic characterization revealed that all presented complexes exhibited enantiotropic mesophases and their type was dependent on the terminal lengths of alkoxy chains. Also, the mesomorphic temperature ranges decreased in the order I/A6 > I/A8 > I/A10 > I/A16 with linear dependency on the chain length. Finally, the density functional theory computational modeling has been carried out to explain the experimental findings. The relation between the dimensional parameters was established to show the effect of the aspect ratio on the mesophase range and stability. The normalized entropy of the clearing transitions (∆S/R) was calculated to illustrate the molecular interaction enhancements with the chain lengths.

Impact of cellulose nanocrystals reinforcement on molecular dynamics and dielectric properties of PCL‐based polyurethane

AbstractThe thermal and dielectric properties of polymer nanocomposites based on polycaprolactone diol‐based PU matrix filled with various weight fractions of cellulose nanocrystals (CNCs) (from 0 to 10 wt%) extracted from the rachis of date palm tree were investigated by differential scanning calorimetry (DSC) and broadband dielectric spectroscopy. The emphasis was on clarifying the impact of the addition of CNC nanofillers on the molecular mobility of the PU matrix. Different dielectric relaxations have been found and the corresponding activation energies have been calculated, by means of the Havriliak–Negami model after fitting the dielectric data. The outcomes were explored in terms of molecular dynamics and interfacial processes. With 2.5 wt% of CNC, the strongest adhesion between matrix and reinforcement was acquired. This research was supported by the use of DSC for thermal properties.

On the Use of Differential Scanning Calorimetry for Thermal Hazard Assessment of New Chemistry: Avoiding Explosive Mistakes

AbstractDifferential scanning calorimetry (DSC) is increasingly used as evidence to support a favourable safety profile of novel chemistry, or to highlight the need for caution. DSC enables preliminary assessment of the thermal hazards of a potentially energetic compound. However, unlike other standard characterisation methods, which have well defined formats for reporting data, the current reporting of DSC results for thermal hazard assessment has shown concerning trends. Around half of all results in 2019 did not include experimental details required to replicate the procedure. Furthermore, analysis for thermal hazard assessment is often only conducted in unsealed crucibles, which could lead to misleading results and dangerously incorrect conclusions. We highlight the specific issues with DSC analysis of hazardous compounds currently in the organic chemistry literature and provide simple “best practice” guidelines which will give chemists confidence in reported DSC results and the conclusions drawn from them.

On the Use of Differential Scanning Calorimetry for Thermal Hazard Assessment of New Chemistry: Avoiding Explosive Mistakes.

Differential scanning calorimetry (DSC) is increasingly used as evidence to support a favourable safety profile of novel chemistry, or to highlight the need for caution. DSC enables preliminary assessment of the thermal hazards of a potentially energetic compound. However, unlike other standard characterisation methods, which have well defined formats for reporting data, the current reporting of DSC results for thermal hazard assessment has shown concerning trends. Around half of all results in 2019 did not include experimental details required to replicate the procedure. Furthermore, analysis for thermal hazard assessment is often only conducted in unsealed crucibles, which could lead to misleading results and dangerously incorrect conclusions. We highlight the specific issues with DSC analysis of hazardous compounds currently in the organic chemistry literature and provide simple "best practice" guidelines which will give chemists confidence in reported DSC results and the conclusions drawn from them.

DSC Analysis of Thermophysical Properties for Biomaterials and Formulations.

The development of freezing and freeze-drying processes for biological samples requires knowledge of the thermophysical properties of the biomaterial and protectant solutions involved. This chapter provides an introduction on the use of differential scanning calorimetry (DSC) to study thermophysical properties of biomaterials in protective solutions. It covers specific methods to study thermal events related to freezing and drying processes including crystallization, eutectic formation, glass transition, devitrification, recrystallization, melting, molecular relaxation, and phase separation.

Construction of a Room-Temperature Eutectic Binary Phase Diagram by Use of Differential Scanning Calorimetry

A eutectic system is a mixture of two or more substances, displaying a melting temperature lower than its standalone components. The eutectic composition displays the lowest melting temperature of all mixtures. Typically, a eutectic system is used as an example of binary phase diagrams to demonstrate to undergraduate students. Herein, the liquidus and solidus define regions in the phase diagram where the mixture is either a liquid, a solid, or a combination of both. This experiment aims to construct the binary phase diagram of a mixture of menthol (M) and lauric acid (LA) by measuring the thermal properties of a wide range of compositions utilizing differential scanning calorimetry (DSC). The solidus and liquidus are uniquely located below room temperature. The eutectic melting temperature is around 12 °C, while the standalone menthol and lauric acid components melt at 36 and 48 °C, respectively. This allows the visual demonstration of the compositions in all of the defined regions in the binary phase diagram. Furthermore, the theory of cryoscopy is utilized to predict the liquidus of the phase diagram. The comparison with the experimentally determined melting temperatures allows the undergraduate students to reflect on the reliability of the derived equation.

Isothermal differential scanning calorimetry analysis of the anionic polymerisation of polyamide-6: Separation by dual asymmetric gaussians

The use of a reactive processing approach for the manufacture of thermoplastic composites is of increasing interest owing to the potential for lower melt viscosities, processing temperatures, and cycle times. These reactive systems, such as the anionic polymerisation of polyamide-6 (APA6), lack the depth of characterisation and modelling required for mould flow simulation for the purposes of part quality assurance and process optimisation as desirable for industrial application. This is particularly important in reactive systems, owing to the potential of part failure through inadequate polymer conversion, and the nature of thermoplastic polymer crystallisation which will occur simultaneously with polymerisation in these systems. A typical experimental technique for the kinetic analysis of polymerisation is through use of Differential Scanning Calorimetry (DSC) to measure the reaction exotherms. Unfortunately, as polymerisation and crystallisation occur simultaneously, the resulting exotherms obscure each other in thermal analysis techniques, inhibiting independent model fitting. An algorithmic approach to the interpretation of kinetic information obtained by isothermal DSC is implemented and discussed, with gaussian curve parameters for a variety of isothermal temperatures and initiator/activator concentrations presented.

Curing and thermal properties of tannin-based epoxy and its blends with commercial epoxy resin

In order to find partial substitution for bisphenol A-based commercial epoxy resin (CE), a bio-based epoxy resin was prepared from eucalyptus tannins through a typical glycidylation reaction with epichlorohydrin. The structure of tannin-based epoxy resin (TE) was confirmed by Fourier transform infrared spectroscopy (FTIR) analysis. Herein, mixtures of TE and CE (TE–CE) were prepared using varying loading amounts (20, 40 and 60) wt/wt%of TE. Tannins used here are produced by solid–liquid extraction from the outer bark of eucalyptus tree, mainly consisting of condensed tannins. Through the use of differential scanning calorimetry (DSC) and FTIR techniques, the reactivity of tannin epoxy with and without commercial epoxy resin to form cross-linking network was investigated. TE was successfully cured with amine-based curing agent. Furthermore, compared to commercial epoxy resin (CE), TE exhibited broad low exothermic peak, insignificant cross-linking properties and low curing enthalpy at different levels of curing agent. Moreover, to study the influence of TE substitution on the curing properties of CE, curing behavior of TE–CE mixtures was investigated by DSC. It was found that TE at high loading levels such as 40 and 60 wt/wt% increases slightly the reactivity of CE by decreasing curing characteristics temperatures such as the initial of curing, peak exotherm and completion of curing temperatures. TE can serve as curing accelerator and has a non-desirable impact on the curing performance of CE resin such as curing enthalpy. And up to 20 wt/wt% of CE could be replaced by TE without any significant reduction in the curing behavior of CE.