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4-Hydroxybenzoic acid, also known as p-hydroxybenzoic acid (PHBA), is a monohydroxybenzoic acid, a phenolic derivative of benzoic acid.It is a white crystalline solid that is slightly soluble in water and chloroform but more soluble in polar organic solvents such as alcohols and acetone. 4-Hydroxybenzoic acid is primarily known as the basis for the preparation of its esters, known as parabens ...
Mass spectral interpretation is the method employed to identify the chemical formula, characteristic fragment patterns and possible fragment ions from the mass spectra. [1] [2] Mass spectra is a plot of relative abundance against mass-to-charge ratio. It is commonly used for the identification of organic compounds from electron ionization mass ...
A mass spectrum is a histogram plot of intensity vs. mass-to-charge ratio (m/z) in a chemical sample, [1] usually acquired using an instrument called a mass spectrometer. Not all mass spectra of a given substance are the same; for example, some mass spectrometers break the analyte molecules into fragments ; others observe the intact molecular ...
The results are presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio.
The dalton (symbol: Da) is the standard unit that is used for indicating mass on an atomic or molecular scale (atomic mass). [1] The unified atomic mass unit (symbol: u) is equivalent to the dalton. One dalton is approximately the mass of one a single proton or neutron. [2] The unified atomic mass unit has a value of 1.660 538 921 (73) × 10 ...
2-Hydroxybenzoic acid, others 138.031694 C6H6O4: 1,2,3,5-Tetrahydroxybenzene 142.026608 C9H6O2: Coumarin 146.036779 C9H8O2: Cinnamic acid 148.05243 C9H10O2: 2-Methoxy-4-vinylphenol, others 150.06808 C10H14O: Carvacrol 150.104465 C8H8O3: 4-Hydroxyphenylacetic acid, others 152.047344 C9H12O2: 4-Ethylguaiacol 152.083729 C7H6O4: Protocatechuic acid ...
Gentisic acid is produced by carboxylation of hydroquinone. [6] C 6 H 4 (OH) 2 + CO 2 → C 6 H 3 (CO 2 H)(OH) 2. This conversion is an example of a Kolbe–Schmitt reaction. Alternatively the compound can be synthesized from salicylic acid via Elbs persulfate oxidation. [7] [8]
UV visible spectrum of protocatechuic acid. Protocatechuic acid (PCA) is a dihydroxybenzoic acid, a type of phenolic acid. It is a major metabolite of antioxidant polyphenols found in green tea. It has mixed effects on normal and cancer cells in in vitro and in vivo studies. [4] It is produced commercially from vanillin. [5]