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At least 19 recordsLinked to original sources
PubMed2026

Thermal analysis techniques for microplastic mass quantification: Methodological challenges and standardization needs.

Microplastics (MPs, 1 &#x3bc;m-5 mm) and nanoplastics (NPs, <1&#x202f;&#x3bc;m) are ubiquitous contaminants requiring standardized quantification methods. This systematic review evaluates thermal analysis techniques for mass-based MP detection, including pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), thermogravimetry-MS (TGA-MS), thermal extraction desorption-GC-MS (TED-GC-MS), and differential scanning calorimetry (DSC). Database searches (Web of Science, from inception to December 1, 2025) following PRISMA guidelines identified studies across seven environmental matrices (water, soil/sediment, atmosphere, biota, human tissues). We identify critical standardization gaps: inconsistent marker ion selection, unvalidated conversion factors for tire and road wear particles (TRWPs), and the absence of certified reference materials for complex matrices. Py-GC-MS demonstrates versatility but suffers from lipid interference in biological samples; TED-GC-MS offers superior sensitivity (sample capacity &#x223c;200&#xd7; Py-GC-MS) but lacks real-time chromatographic monitoring. To advance data comparability, we propose: (i) harmonized ion selection hierarchies based on specificity-sensitivity balance, (ii) matrix-specific TRWP quantification protocols, and (iii) inter-laboratory validation using environmental reference materials. This review provides a methodological roadmap for standardizing thermal analysis in MP research.

Humans↗
PubMed1977

[Differential thermal analysis of the organic fraction of bone].

Thermal decomposition analysis of Bovine femur bone has been carried out by means of a Micro Differential Thermal Analyser. The analysis of both thermograms and amino acid compositions has revealed the complexity of collagen degradation mechanisms.

Amino Acids↗
PubMed1978

Thermal analysis of dental impression waxes.

Ten dental impression waxes were characterized by penetration and differential thermal analysis. Penetration and initial transition temperatures were directly correlated. Penetration at 37 C ranged from 2.5 to 22% for bite waxes and was 100% for corrective waxes. Distortion of an impression wax may occur upon removal from the mouth.

Bees↗
PubMed1978

Thermal analysis of the spores of Bacillus cereus with special reference to heat activation.

The heat activation of bacterial spores was studied by means of differential thermal analysis in the temperature range 30-110 degrees C using the spores of Bacillus cereus. The thermogram showed three endothermic peaks at 56, 95, and 103 degrees C with one exothermic peak at 105 degrees C during the heating process. The spore coat separated from the native spores also showed a peak at 56 degrees C on its heating thermogram. The peak at 56 degrees C was reversible for both native spores and the spore coat. It was suggested that this peak at 56 degrees C might be related to the heat-activation process that takes place in the spore-coat region. It seems that the peak is due to the denaturation or the structural change of the spore-coat protein that might facilitate either the permeation of germination stimulators or the release of some germination inhibitor into or out of the spores.

Bacillus cereus↗
PubMed1977

Determination of phase transitions in gutta-percha by differential thermal analysis.

Pure gutta-percha was heat-treated in a differential thermal analyzer. The high melting form crystallized on cooling when gutta-percha was heated to 70 C or less. Above 74 C, crystallization into the low melting form predominated. Either polymorph can be selectively crystallized by control of the heat-treatment temperature before cooling.

Chemical Phenomena↗
PubMed1976

The application of differential thermal analysis and thermogravimetric analysis to dating bone remains.

Thirty-four samples of bone remains of known time since death were studied by using DTA, TGA, and derivative-TGA techniques. The DTA patterns enable us to distinguish recent from old (more than 100 years) bones. The TGA curve is also significant for an extreme series. Both DTA and TGA curves show a correlation that allows us to obtain patterns with high significance for the extreme series. They also make evident the decomposition grade that bone organic material undergoes during the postmortem putrefactive process.

Age Determination by Skeleton↗
PubMed1976

Changes in crystallinity and solubility on comminution of digoxin and observations on spironolactone and oestradiol.

Using infrared spectroscopy, X-ray diffractometry, differential thermal analysis, scanning electron microscopy, solubility and dissolution rate measurements, it was demonstrated that the comminution of digoxin results in the appearance of an amorphous phase. The examination of spironolactone and 17 beta-oestradiol by infrared spectroscopy and differential thermal analysis showed that these compounds also undergo changes in their crystallinity on grinding. Since the dissolution characteristics of poorly soluble drugs may be complex functions of surface area and crystallinity, it is concluded that the most pertinent method for standardizing a sample of a polymorphic drug of low solubility is by means of a powder dissolution test, as the results embrace the influences of particle size, aggregation and polymorphism.

Chemistry, Pharmaceutical↗
PubMed1979

Melting-profile analysis of thermal stability of thermolysin. A formulation of temperature-scanning kinetics.

The melting-profile method consists of a continuous observation of a structural parameter while the temperature of the sample is raised at a constant rate [Fugita, S. C., & Imahori, K. (1974) IN Peptides, Polypeptides and Proteins (Blout, E. R., Bovey, F. A., Goodman, M., & Lotan, N., Eds.) p 217, Wiley, New York, N.Y.]. An analytical solution to the melting profile was formulated for the two-state irreversible process and called temperature-scanning kinetics. The theory was tested with thermolysin with consistent results, and the thermodynamic parameters of thermal denaturation were calculated: deltaH identical to = 80.3 kcal/mol, deltaS identical to = 153 eu. These values agreed with the corresponding values obtained from the classical constant-temperature relaxation kinetics. The possibilities of temperature-scanning kinetics are discussed.

Calcium↗
PubMed1979

[Experiences with instrumental methods for urinary calculi analysis].

To reduce the urinary calculi incidence by calculi formers, it is important to know the composition of these stones. Unfortunately the chemical analysis does not give very reliable results. Looking for a better method to analyse urinary calculi, three instrumental methods were tested: infared spectroscopy, thermal analysis and X-ray diffraction. The experimental results and economical considerations show that the X-ray diffraction analysis of urinary calculi would meet the goal of improved care of patients with stones.

Humans↗
PubMed1979

Elemental analysis of bone mineral by backscattering of alpha particles.

Backscattering of 2 MeV alpha particles has been applied for the first time to studies of the inorganic substances of human bone. Bone samples taken from the femoral shaft (dense bone) and iliac crest (spongy bone) of 18 cadavers were analysed for the calcium, phosphorus and oxygen content, after lyophilisation and heating for 1.5 h at 500 degrees C to remove water and organic material. The backscattering method produces a spectrum in which all the elements present in the sample except hydrogen can be seen at once. The reproducibility of the measurements was less than 2%. No previous studies were found in the literature of the measurement of elemental oxygen in bone samples. Ca/P ratios varied from 1.97 to 2.47, Ca/O ratios from 0.76 to 0.91 and P/O ratios from 0.34 to 0.41, the latter two being about 10--15% lower than expected if bone mineral were hydroxyapatite (Ca/O = 0.96 and P/O = 0.44). The results are consistent with previous work on Ca/P ratios but the low Ca/O and P/O ratios could not be explained without postulation of crystal or hydroxyl water in bone mineral. Support for the explanation was gained by differential gravimetric and thermal analysis.

Alpha Particles↗