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Synthetic Polymers in Cosmetics
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
A variety of terms, some of them confusing, are used in the patent and open literature to describe the “amount” of cationic charge on the cationic polymer. Table 10 lists three of the most common terms. The distinction of cationic nitrogen from other forms of noncationic nitrogen in these polymers is important. For instance, both Kjeldahl and combustion analysis, which report the combination of cationic nitrogen and other nitrogen, can be applied to Polyquaternium-7. Only the cationic nitrogen is, however, important in these charge calculations.
Procedures for Calculating Empirical and Molecular Formulas
Published in Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk, Survival Guide to General Chemistry, 2019
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk
Example: Assume a certain compound of aluminum and sulfur (AlxSy) can be analyzed by combustion analysis. A 17.50 gram sample was burned in air to form 22.40 grams of sulfur dioxide (SO2). All of the sulfur in the original sample is found in the SO2. Determine the simplest formula. Step (1) first requires the determination of the mass of elemental S in the original sample. The mass S in the molecule SO2 can be calculated using the concept of percent mass and, thus, fractional mass (see Chapter 5).Fractional mass using a molar mass calculation:Using fractional mass to find the mass of any element in a specific sample:Step (1) has produced the mass ratio; steps (2) and (3) are performed as previously. As an alternative to fractional mass conversion through moles can be used:(2) moles Al = 6.29 g/26.98 g/mole = 0.233 moles Al(3a)0.233 is the smallest mole value found; divide all mole numbers by this value:(3b) 2 × 1 mole Al = 2 mole Al
Doxorubicin delivery systems based on doped CaCO3 cores and polyanion drug conjugates
Published in Journal of Microencapsulation, 2021
Natalia Sudareva, Olga Suvorova, Natalia Saprykina, Helen Vlasova, Alexander Vilesov
Elemental compositions of the studied samples were determined by two methods:Elemental composition of the samples was determined by energy-dispersive X-ray spectroscopy (EDS) using an X-Max 80 detector (Oxford Instruments, Oxford, UK). The method does not allow determining hydrogen content.Combustion analysis (burning sample at high temperature and catalytic oxidation of the formed products followed by gas chromatography analysis) was performed using a Vario EL III elemental analyser (Langenselbold, Germany). The method does not allow determining oxygen content.
Two-level delivery systems based on CaCO3 cores for oral administration of therapeutic peptides
Published in Journal of Microencapsulation, 2018
Natalia Sudareva, Olga Suvorova, Natalia Saprykina, Natalia Smirnova, Petr Bel'tyukov, Sergey Petunov, Andrey Radilov, Alexander Vilesov
Combustion analysis (burning sample at high temperature and catalytic oxidation of the formed products followed by gas chromatography analysis) was performed using a Vario EL III elemental analyser (Langenselbold, Germany). The method does not allow determining oxygen content.