For optimal results in HPLC analysis, it is recommended to measure absorbance at a wavelength that matches the absorption maximum of the compound(s) being analyzed. The UV spectrum shown can assist in selecting an appropriate wavelength for your analysis. Please note that certain mobile phases and buffers may block wavelengths below 230 nm, rendering absorbance measurement at these wavelengths ineffective. If detection below 230 nm is required, it is recommended to use acetonitrile and water as low UV-transparent mobile phases, with phosphoric acid and its salts, sulfuric acid, and TFA as buffers.
For some compounds, the UV-Vis Spectrum is affected by the pH of the mobile phase. The spectra presented here are measured with an acidic mobile phase that has a pH of 3 or lower.

HPLC Method for Ethylparaben, Methylparaben sodium, Propylparaben sodium, Methylparaben, Parabens, Propylparaben on Newcrom AH by SIELC Technologies

High Performance Liquid Chromatography (HPLC) Method for Analysis of Ethylparaben, Methylparaben sodium, Propylparaben sodium, Methylparaben, Parabens, Propylparaben.

Methylparaben, also known as Methyl 4-hydroxybenzoate, is a paraben with the chemical formula C₈H₈O₃. It is used as a preservative in food, cosmetics, and pharmaceuticals as it is said to have antimicrobial and antifungal properties. It is considered safe for use in low concentrations, but it may cause irritation or contact dermatitis in rare cases and for those who are allergic.

Ethylparaben is an ethyl ester of p-hydroxybenzoic acid with the chemical formula C₉H₁₀O₃. It is used as a preservative in food, cosmetics, and pharmaceuticals due to it’s antimicrobial and antifungal properties. There are ongoing debates in regards to it’s safety as it relates to human consumption,

Propylparaben is a n-propyl ester with the chemical formula C₁₀H₁₂O₃. It is used as a preservative in food, cosmetics, and personal care products due to it’s antimicrobial properties. Studies show that it absorbs through the skin and remains in the body, leading to the European Union banning it. California had banned it for use in food, but not in other uses.

You can find detailed UV spectra of Methylparaben and information about its various lambda maxima by visiting the following link.

You can find detailed UV spectra of Ethylparaben and information about its various lambda maxima by visiting the following link.

You can find detailed UV spectra of Propylparaben and information about its various lambda maxima by visiting the following link.

Ethylparaben, Methylparaben sodium, Propylparaben sodium, Methylparaben, Parabens, Propylparaben can be retained and analyzed using the Newcrom AH stationary phase column. The analysis utilizes an isocratic method with a simple mobile phase consisting of water and acetonitrile (MeCN) with a sulfuric acid buffer. Detection is performed using UV.

HPLC Method for EDTA (Ethylenediaminetetraacetic Acid), Methylparaben, Methylparaben sodium, 2-Phenoxyethanol on Newcrom BH by SIELC Technologies

High Performance Liquid Chromatography (HPLC) Method for Analysis of EDTA (Ethylenediaminetetraacetic Acid), Methylparaben, Methylparaben sodium, 2-Phenoxyethanol.

Ethylenediaminetetraacetic acid (EDTA) is a synthetic amino acid with the chemical formula C₁₀H₁₆N₂O₈. It is typically used in industry to sequester metal ions, which helps prevent change of colors in textiles and uneven bleaching in paper. Due to it being a chelator, it is also used to soften water during laundry, remove hydrogen sulfide from gas streams, as well as treat mercury and lead poisoning.

Phenoxyethanol is a synthetic compound with the chemical formula C₈H₁₀O₂. It is said to have antimicrobial and preservative properties, leading to wide use of it in cosmetics, medicine, and biocides. It is considered safe in the US and Europe at limited concentrations.

Methylparaben, also known as Methyl 4-hydroxybenzoate, is a paraben with the chemical formula C₈H₈O₃. It is used as a preservative in food, cosmetics, and pharmaceuticals as it is said to have antimicrobial and antifungal properties. It is considered safe for use in low concentrations, but it may cause irritation or contact dermatitis in rare cases and for those who are allergic.

You can find detailed UV spectra of EDTA + Fe complex and information about its various lambda maxima by visiting the following link.

You can find detailed UV spectra of Methylparaben and information about its various lambda maxima by visiting the following link.

EDTA (Ethylenediaminetetraacetic Acid), Methylparaben, Methylparaben sodium, 2-Phenoxyethanol can be retained and analyzed using the Newcrom BH stationary phase column. The analysis utilizes a gradient method with a simple mobile phase consisting of water and acetonitrile (MeCN) with a sulfuric acid buffer. Detection is performed using UV.

HPLC Method for Carbocisteine, Methylparaben sodium, Propylparaben sodium, Propylparaben, Methylparaben on Primesep 100 by SIELC Technologies

High Performance Liquid Chromatography (HPLC) Method for Analysis of Carbocisteine, Methylparaben sodium, Propylparaben sodium, Propylparaben, Methylparaben.

Carbocysteine is a medication that reduces the viscosity of mucus making it easier to cough up. Methylparaben and propylparaben are used as preservatives in cosmetics, pharmaceuticals and food. They can be separated in HPLC on a Primesep 100 mixed-mode column by both hydrophobic and ionic properties present on the stationary phase. The analytical method uses acetonitrile (ACN) gradient and water with sulfuric acid (H2SO4) as buffer and UV detected at 200nm.

Dextromethorphan is one of the common cough suppressants used in many drug composition. It is in tablets and syrups as an antitussive drug. Composition often has preservatives like parabens. Dextromethorphan is a hydrophobic, basic drug which is used as a bromide salt in drug compositions. Dextromethorphan and two parabens (methyl paraben and propyl paraben) were separated on Primesep C reversed-phase cation-exchange column. Several impurities were observed and are well separated from the main components of the drug composition. Method can be used for various formulations in QC and production environment.

Codeine and two parabens are separated by mixed-mode chromatography. Codeine is retained by reversed-phase and cation-exchange mechanisms and parabens are retained by reversed-phase mechanism. The retention time of codeine can be adjusted by changing the amount of acetonitrile, buffer concentration, and buffer pH. The mobile phase for this column and its separation are fully compatible with UV, ELSD, LC/MS and prep chromatography, various organic and inorganic acids, and corresponding buffers can be used.

Codeine is a hydrophobic basic drug which is used in many drug compositions as an analgetic, antitussive, anxiolytic, and sedative agent. Codeine is widely used as a moderate pain and cough reliever. It is usually part of complex composition and comes in the form of a tablet or syrup. Several preservatives are used in most of the drug composition and include parabens and benzoates. The mixture of codeine, methyl and propyl parabens was separated on Primesep C mixed-mode reversed-phase cation-exchange column. Codeine is retained by reversed-phase and cation-exchange mechanisms and parabens are retained by reversed-phase mechanism. No ion-pairing reagent is required since Primesep C mixed-mode stationary phase has an ion-pairing reagent attached to the surface.

Polar amino acids are very often used as components of vitamin and supplement composition. Analysis of such complex composition is a challenging task. In this application, 5 amino acids (asparagine, glutamic acid, proline and arginine) and two preservatives (methyl paraben and propyl paraben) are separated on a Primesep 100 reversed-phase cation-exchange column with LC/MS compatible mobile phase. Method does not require ion-pairing reagent in the mobile phase. Compounds are monitored by ELSD and UV. Method is validated for quantitation of underivatized amino acids in complex mixtures. The method is simple and robust and can be used for analysis of various vitamin formulations.

Parabens are common preservatives in pharmaceutical and cosmetic industries. They are esters of p-hydroxybenzoic acid. Method for separation of methyl paraben, propyl paraben, benzonitrile and toluene was developed on a Obelisc R column. All four compounds are neutral and are retained by reverse-phase mechanism. In case of reversed-phase stationary phase, no effect of pH is observed. Retention time for all four compounds changes on an Obelisc R column when pH is changed. pH of the mobile phase affects ionization state of stationary phase. Obelisc R column has C12 carbon chain and carboxylic acid with pKa of 4. At lower pH (pH 2, TFA), carboxylic acid of stationary phase is not ionized and thus adds hydrophobicity to stationary phase. Obelisc R column can be used for analysis of basic, acidic and neutral compounds with suitable detection techniques – UV, ELSD, CAD, LC/MS.

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Parabens possess antibacterial and antifungal properties and are therefore widely used in pharmaceutical and cosmetic industries as preservatives in products. Parabens and benzoic acid can be baseline separated in a short time frame using Primesep B2 reverse-phase HPLC column with a simple mobile phase of water, acetonitrile (ACN, MeCN) and phosphoric acid of 0.1% as buffer. UV detection at 210nm.