Evaluation of methods for the determination of water in substances with unknown chemical and thermal behaviour

Hinz, Dirk C.

doi:10.1016/j.jpba.2006.08.002

Cited by 20 publications

(29 citation statements)

References 6 publications

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“…11,29 Additionally, the technique may not release all the entrained solvent 1 or tightly bound crystallization water. 29,32 Other disadvantages are the large amount of sample required 1,3,29 and the long analysis time. 9,24,29 Gas chromatography (GC) is the most used technique for residual solvent quantification.…”

Section: Introductionmentioning

confidence: 99%

“…29 The correct assignment of the type of volatile components, namely water or residual solvent, is easier to carry out when the equipment is connected to a mass spectrometer (TGA-MS). The technique requires only 2-5 mg sample 1 and can recognize the types of water binding.…”

Section: Introductionmentioning

confidence: 99%

“…The technique requires only 2-5 mg sample 1 and can recognize the types of water binding. 29 The long analysis time may be a disadvantage.…”

Section: Introductionmentioning

confidence: 99%

“…24 Another drawback of the technique is the restriction to use the direct addition in case of analytes that are not soluble in or that react with the KF reagent, 6,29 for instance thiols, 11,31 aldehydes, cetones, amines, cupric salts and ferric salts. 11 Furthermore, it does not provide information about residual solvents.The loss on drying (LOD) technique is largely used in pharmaceutical laboratories to determine the total amount of volatiles, i.e., water and residual solvents 9,29,32 vaporized under the experimental conditions. The test is quite simple, 3,29 and depends only on a properly calibrated analytical balance and an oven usually programmed at 105 ºC (or a vacuum oven in case of thermolabile APIs).…”

mentioning

confidence: 99%

“…The technique requires only 2-5 mg sample 1 and can recognize the types of water binding. 29 The long analysis time may be a disadvantage.The infrared spectroscopy (IR) has a high potential for identification (classification) and quantification, especially when combined to chemometric methods. 5,41 It is non-destructive, requires minimum sample preparation, 41 and can be used to determine water 42 and residual solvents.…”

mentioning

confidence: 99%

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Determination of volatiles in pharmaceutical certified reference materials

Nogueira¹,

Queiroz²,

Silva³

et al. 2012

J. Braz. Chem. Soc.

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Este trabalho compara os resultados obtidos na determinação de voláteis (água e solventes residuais) em novos materiais de referência certificados (MRC) ou candidatos a MRC dos ingredientes ativos farmacêuticos (API) captopril, metronidazol, diclofenaco sódico, diclofenaco potássico e furosemida, através do uso de diferentes técnicas: perda por dessecação (LOD), titulação coulométrica tipo Karl Fisher (KF), cromatografia gasosa (injeção por headspace estático) com detector por ionização em chama (sHS-GC-FID) e com espectrômetro de massas (sHS-GC-MS), análise termogravimétrica (TGA) e espectroscopia no infravermelho próximo (NIR) com análise estatística multivariada dos resultados. As três primeiras técnicas levaram a resultados complementares na determinação de voláteis, enquanto as outras duas mostraram pouca sensibilidade para a determinação de voláteis na faixa de concentração avaliada. A perda por dessecação foi considerada a técnica mais apropriada para determinação da fração mássica de voláteis a ser utilizada no cálculo do teor de API por balanço de massa.This work compares the results obtained for the determination of volatiles (water and residual solvents) in new certified reference materials (CRM) or candidate CRMs of the active pharmaceutical ingredients (API) captopril, metronidazole, sodium diclofenac, potassium diclofenac and furosemide, by means of different techniques: loss on drying (LOD), Karl Fischer (KF) coulometric titration, static headspace gas chromatography with flame ionization detection (sHS-GC-FID) and with mass spectrometry (sHS-GC-MS), thermogravimetric analysis (TGA) and near infrared spectroscopy (NIR) with multivariate chemometric analysis of results. The first three methods led to complementary results. The two other techniques were not sufficiently sensitive to determine volatiles in the concentration range evaluated. The loss on drying method was considered the most appropriate to determine the mass fraction of the volatiles to be used in the mass balance calculation of the API mass fraction in the pharmaceutical CRMs.Keywords: volatiles, water, residual solvents, active pharmaceutical ingredient (API), certified reference materials (CRM), analytical quality control IntroductionSeveral are the reasons for determining the mass fractions of water and residual solvents in pharmaceuticals, including their influence on the physicochemical 1-7 and microbiological stability of raw materials and finished products, their potential toxicity [1][2][3]8 and also economic aspects 9 since their presence results in analyte mass fractions smaller than 100%. Residual solvents may be introduced in active pharmaceutical ingredients (API) during their synthesis, especially if the final purification step is carried out by crystallization in different solvents, as well as during drug products formulation and manufacturing. 1,7,8 In the particular case of certified reference materials (CRM) of APIs, the determination of volatiles is essential both to demonstrate the compliance with Pharmacopeial acc...

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…The technique requires only 2-5 mg sample 1 and can recognize the types of water binding. 29 The long analysis time may be a disadvantage.…”

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Determination of volatiles in pharmaceutical certified reference materials

Nogueira¹,

Queiroz²,

Silva³

et al. 2012

J. Braz. Chem. Soc.

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Metrologically Traceable Determination of the Water Content in Biopolymers: INRiM Activity

et al. 2017

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Water content in materials is a key factor affecting many chemical and physical properties. In polymers of biological origin, it influences their stability and mechanical properties as well as their biodegradability. The present work describes the activity carried out at INRiM on the determination of water content in samples of a commercial starch-derived biopolymer widely used in shopping bags (Mater-Bi ®). Its water content, together with temperature, is the most influencing parameter affecting its biodegradability, because of the considerable impact on the microbial activity which is responsible for the biopolymer degradation in the environment. The main scope of the work was the establishment of a metrologically-traceable procedure for the determination of water content by using two electrochemical methods, namely coulometric Karl Fischer (cKF) titration and Evolved Water Vapour (EWV) analysis. The obtained results are presented. The most significant operational parameters were considered and a particular attention was devoted to the establishment of metrological traceability of the measurement results by using appropriate calibration procedures, calibrated standards and suitable certified reference materials. Sample homogeneity and oven-drying temperature were found to be the most important influence quantities in the whole water content measurement process. The results of the two methods were in agreement within the stated uncertainties. Further development is foreseen for the application of cKF and EWV to other polymers.

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Measurement of Grain and Grain Products Moisture Content by Ultrahigh-Frequency Method: Influence of Grain Density Inhomogeneity on the Mass Ratio of Moisture

Ikramov¹,

Kalandarov

2022

Meas Tech

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Evaluation of methods for the determination of water in substances with unknown chemical and thermal behaviour

Cited by 20 publications

References 6 publications

Determination of volatiles in pharmaceutical certified reference materials

Determination of volatiles in pharmaceutical certified reference materials

Metrologically Traceable Determination of the Water Content in Biopolymers: INRiM Activity

Measurement of Grain and Grain Products Moisture Content by Ultrahigh-Frequency Method: Influence of Grain Density Inhomogeneity on the Mass Ratio of Moisture

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