Mobile Phase Of Ethanol Research Articles

An integrated paradigm between green analytical chemistry and quality-by-design for robust analysis of alcaftadine and ketorolac tromethamine in aqueous humor via sustainable chromatographic methods

The field of pharmaceutical industry has witnessed the launch of a new co-formulated eye drop, composed of alcaftadine and ketorolac tromethamine, for alleviating allergic conjunctivitis. Such new formulation evokes the need for a sensitive, robust and fast analytical method capable of their quantification in their dosage form, in aqueous humor for pharmaco-kinetics studies as well as in presence of plausible degradation products. In this work, two validated stability-indicating chromatographic methods were developed for alcaftadine and ketorolac assaying with good adherence to values of green analytical chemistry. Drugs stabilities were tested under various stress conditions where drugs showed liability for oxidative degradation only. For the first chromatographic method, an integrated merger between analytical quality-by-design and green analytical chemistry was implemented via a UPLC method coupled with photo-diode array detector. A short C18 analytical column of 100 mm was utilized with mobile phase of ethanol: aqueous solution pH 4.0 containing 0.1% triethylamine (40: 60, by volume). Second method was thin layer chromatographic one using HPTLC silica plates as a stationary phase and a developing system of dichloromethane: ethanol (5:4, by volume). Both methods achieved to selectively quantify the studied drugs with high accuracy and precision without any interference from degradation products or related excipients in eye drops. The methods were also successfully exploited for ALF and KTC assaying in rabbit aqueous humor, with no need for prior extraction procedures, for further pharmacokinetic studies. Finally, usage of green solvents gives us the advantage of applying various evaluation tools to conclude method greenness.

Greens assessment of RP-UPLC method for estimating Triamcinolone Acetonide and its degraded products compared to Box-Behnken and Six Sigma designs

ABSTRACT A study on green analytical chemistry aims to develop eco-friendly alternatives to hazardous substances and minimize waste generation. The study thoroughly examined various tools to determine their greenness. A newly validated RP-UPLC method was then employed quantitatively to detect Triamcinolone Acetonide (TRA) in a creamy pharmaceutical formulation using UPLC BEH C18 (50 × 2.1 mm, 1.7μm) column for analysis, with a detection wavelength set at 240 nm. The Box-Behnken design was developed to efficiently determine the optimal chromatographic conditions while minimizing the required trials. The study effectively assessed the impact of three independent variables on various responses, including retention time, tailing factor, and theoretical plates. The variables examined ethanol ratio, pH levels, and flow rate were meticulously tested to optimize experimental conditions. The utilization of desirability and overlay plots, along with a mobile phase of ethanol and purified water in a volumetric ratio of 30:70 and pH adjustment to 5.0. Calibration curves were constructed to assess the linearity of TRA within the concentration range of 2.5-50 µg/mL, yielding correlation coefficients (r = 0.9999). The accuracy was validated through recovery studies with the acceptable range of 99.6-101.2%. The specificity of the method has been validated by conducting forced degradation studies per ICH guidelines.

Environmental benign RP-HPLC method for the simultaneous estimation of anti-hypertensive drugs using analytical quality by design

ABSTRACT Green analytical procedures replace harmful organic modifiers with green solvents without affecting chromatographic performance, enabling industries and research laboratories to develop green analytical methods. Benidipine hydrochloride (BEN) and Chlorthalidone (CHD) were used to treat hypertension. The literature indicates that no method for determining BEN and CHD combines RP-HPLC with green Analytical Quality by Design (AQbD) for long-term use. This study aimed to develop a green RP-HPLC for determining BEN and CHD by incorporating analytical quality by design with green chemistry principles. A central composite design was used for optimization, with 40% ethanol content and flow rate chosen as critical variables. Separation was achieved using Agilent Eclipse Plus (C18, 250 mm × 4.6 mm i.d, 5 μm) with a mobile phase of ethanol and potassium dihydrogen orthophosphate (orthophosphoric acid to 3.5) in a ratio of 40:60 v/v at 1 ml/min, detection wavelength at 230 nm. Retention times for CHD and BEN were 3.1 and 5.1 min, respectively. The concentration ranges for BEN and CHD were 3.2–4.8 μg/ml and 5.0–7.5 μg/ml, respectively. The proposed method was eco-friendly and assessed using green evaluation tools. Thus, AQBD and green technologies provide regular BEN and CHD analysis in pharmaceutical formulations without environmental impact.

Environmental benign AQbD based estimation of ketoconazole and beclomethasone by RP-HPLC and multi-analytical UV spectrophotometric method

Hazardous chemicalsare one of the most significant adverse effects of drug analysis. Chemicalwaste generatedat every stage of the analysisfound to bein significant concentrations during quality testing. Green analytical chemistry provides a safe environment for drug analysis. Three simple and environmentally sustainable UV spectrophotometric andliquid chromatographic techniques were established to simultaneously measure Ketoconazole and Beclomethasone dipropionate in their bulk and cream formulation. Firstly, the spectrophotometric estimation deals with three green methods: absorption ratio, the first-order absorption ratio, and the area under curve methods. The second approach was green rotatable centralcomposite analytical quality by design-based RP-HPLC method with an optimized mobile phase of ethanol: 0.1 M potassium dihydrogen phosphate buffer (pH 2.5) 33: 67 v/v. The separation was accomplished using an ODS reversed-phase column (250 × 4.6 mm, 5 µm) operating at a 1.0 mL/min flow rate. The determination was performed using the concentrations ranging for Ketoconazole 140–260 µg/mL and Beclomethasone 1.75–3.75 µg/mL (R2 = 0.9991–0.9999). The results showed that the Forced degradation experiments indicate that the drugs degrade under their intended circumstances. Green solvents were utilized in the developed techniques since they significantly impact environmentally benign analytical methods. The proposed techniques have been validated in linearity, accuracy, and precision based on International Council on Harmonization guidelines and green assessment tools, with acceptable results. These techniques shall be employed in place of methods that utilized toxic chemicals for determination and are easily adaptable for routine analysis.

Molecular Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Effect

Diet pattern resulting in hyperlipidemia is likely the main factor of atherosclerosis development. Balinese have been using Andrographis paniculata (Sambiloto) traditionally to maintain their lipid blood level and stamina. Andrographolide (AND) is its active compound. Therefore, molecular pharmacology study of AND on atherosclerosis-related diseases is urgently needed. The study aimed to develop a Thin Layer Chromatography (TLC) fingerprint method for Sambiloto standardization and to carry out the pharmacological effect of this compound on atherosclerosis prevention. This study comprised of several stages: development of the TLC fingerprint, pre-clinical research including atherosclerosis induction in an animal model, experimental treatment and prevention of atherosclerosis development in the animal model using AND, comparison of the results with those for atorvastatin treatment, and in-silico docking simulation of AND’s molecular pharmacological effect. TLC with a ratio of 9:1 (v/v) chloroform: ethanol mobile phase was found to be a suitable method for Sambiloto standardization. Rat diets composition of 5% duck yolk, 10% pork fat, Vit D3 20,000 IU, and 1% calcium induced atherosclerosis development. Daily administration of AND at 1.5 mg/kg rat body weight with atherogenic food prevented atherosclerosis development. The docking simulation showed that AND interacted well with NF-kB, ICAM-1, VCAM-1, TNFI±, IFN-I³ and Cyt MAP kinase P32 proteins responsible for the anti-atherosclerotic effect. Sambiloto is a potential traditional herbal medicine for use in treating and preventing hyperlipidemia from triggering atherosclerosis-related disease development. AND inhibited the ox-LDL formation and interacted well with the atherosclerosis-protein receptor targets. How to Cite this Article Pubmed Style Warditiani NK, Sari PMNA, Ramona Y, Wirasuta MAG. Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Effect. SRP. 2020; 11(9): 201-206. doi:10.31838/srp.2020.9.33 Web Style Warditiani NK, Sari PMNA, Ramona Y, Wirasuta MAG. Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Effect. http://www.sysrevpharm.org/?mno=4695 [Access: March 28, 2021]. doi:10.31838/srp.2020.9.33 AMA (American Medical Association) Style Warditiani NK, Sari PMNA, Ramona Y, Wirasuta MAG. Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Effect. SRP. 2020; 11(9): 201-206. doi:10.31838/srp.2020.9.33 Vancouver/ICMJE Style Warditiani NK, Sari PMNA, Ramona Y, Wirasuta MAG. Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Effect. SRP. (2020), [cited March 28, 2021]; 11(9): 201-206. doi:10.31838/srp.2020.9.33 Harvard Style Warditiani, N. K., Sari, . P. M. N. A., Ramona, . Y. & Wirasuta, . M. A. G. (2020) Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Effect. SRP, 11 (9), 201-206. doi:10.31838/srp.2020.9.33 Turabian Style Warditiani, Ni Kadek, Pande Made Nova Armitha Sari, Yan Ramona, and Made Agus Gelgel Wirasuta. 2020. Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Reviews in Pharmacy, 11 (9), 201-206. doi:10.31838/srp.2020.9.33 Chicago Style Warditiani, Ni Kadek, Pande Made Nova Armitha Sari, Yan Ramona, and Made Agus Gelgel Wirasuta. Molecular Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Effect. Systematic Reviews in Pharmacy 11 (2020), 201-206. doi:10.31838/srp.2020.9.33 MLA (The Modern Language Association) Style Warditiani, Ni Kadek, Pande Made Nova Armitha Sari, Yan Ramona, and Made Agus Gelgel Wirasuta. Molecular Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Effect. Systematic Reviews in Pharmacy 11.9 (2020), 201-206. Print. doi:10.31838/srp.2020.9.33 APA (American Psychological Association) Style Warditiani, N. K., Sari, . P. M. N. A., Ramona, . Y. & Wirasuta, . M. A. G. (2020) Pharmacology Study of Andrographolide Extracted from Andrographis Paniculata on Atherosclerosis Preventive Reviews in Pharmacy, 11 (9), 201-206. doi:10.31838/srp.2020.9.33

Analisa Kualitatif Asam Retinoat pada Sediaan Krim Malam di Pasar Klaten dengan Metode Kromatografi Lapis

Some cosmetics are still found chemicals that are harmful to the skin, such as Mercury, Hydroquinone, Retinoic Acid. These materials have been banned. so researchers are interested in researching Retinoic Acid. Retinoic acid is a hard drug and can only be purchased by prescription from a doctor, but in reality many cosmetics containing retinoic acid are sold freely. Side effects caused include: making the skin feel burned, carcinogenic and teratogenic. The purpose of this study was to carry out a qualitative analysis of retinoic acid compounds in night creams using the thin layer chromatography (TLC) method. The research method was an observational study with the silica gel 60 F 254 nm stationary phase and the n-hexane: ethanol mobile phase (6: 4). From the research that has been done shows the average Rf price of creamA is 0.94; cream B that is 0.90; C cream that is 0.92; creamD is 0.94; cream that is 0.89; while the standard Rf is 0.97. when observed under UV light 254 nm has a dark green spot that corresponds to a standard retinoic acid has a dark green spot so that it can be stated that A, B cream, C cream, D cream, and E cream contain positive retinoic acid.

METODE ISOLASI YANG MUDAH DALAM ISOLASI SENYAWA β-KAROTEN DARI LABU KUNING (Cucurbita moschata Duch ex Poiret)

ABSTRACTPumpkin (Cucurbita moschata Duch ex Poiret), a fruit that contains several compounds, has activities to protect the human body from free radicals. Provitamin A is recognized as an antioxidant compound. Antioxidants can protect the body’s damage caused by free radicals. The purpose of this study was to isolate beta carotene compounds and test the purity of beta carotene isolates obtained using DR-UV and infrared spectrophotometry. Pumpkin is extracted using acetone: petroleum ether with a ratio (1: 1). Identification of beta carotene from extracts was carried out using TLC with the mobile phase of ethanol: acetone: n-hexane with a ratio (2: 1: 1) and scan spectrum using a UV-Vis spectrophotometer. Beta carotene was identified as the result of TLC elution on UV 254 and 366 nm which showed 2 spots. Detection of beta carotene spectra was carried out in the range of 350 to 550 nm and obtained beta carotene peaks at wavelength x nm. The extract purification process was carried out using Preparative TLC with the mobile phase of ethanol: acetone: n-hexane with a ratio (2: 1: 1) and obtained isolates cleaned first using chloroform: methanol ratio of 1: 1. The isolates were dried and tested using DR-UV and infrared spectrophotometry. Isolates from Cucurbita moschataDuch ex Poiret extract) contain beta carotene, zeaxanthin.Keywords: pumpkin; beta carotene; isolation

Effect of the Concentration of an Organic Modifier in a Water–Ethanol Mobile Phase on the Retention and Thermodynamics of Adsorption of Enantiomers of Hydroxy Acids and Their Derivatives on a Chiral Adsorbent with a Grafted Antibiotic Eremomycin

Patterns of the retention and the thermodynamics of adsorption of enantiomers of aromatic hydroxy acids and their derivatives on a chiral stationary phase with a grafted macrocyclic antibiotic eremomycin from water–ethanol eluents under the conditions of linear liquid chromatography are studied. Dependences of the characteristics of retention, separation, and thermodynamic quantities on the concentration of the organic modifier in the eluent are found. The relationship between the structure of the investigated adsorbates and the retention and selectivity of the separation of their enantiomers is shown. It is demonstrated how extrathermodynamic correlations can be used to obtain information on the mechanism of adsorption. The difference between the mechanisms of adsorption of the enantiomers of hydroxy acids and their esters, and by hydroxy acids with a reverse order of elution of the (S)- and (R)-enantiomers, is found.

Смешанные хиральные неподвижные фазы в хроматографии (обзор)

Обсуждается использование смешанных селекторов в газовой и высокоэффективной жидкостной хроматографии для разделения оптических изомеров. Они позволяют повысить универсальность хиральной фазы. В газовой хроматографии широко и успешно используются смеси модифицированного β-циклодекстрина. В ВЭЖХ наиболее изучены смешанные хиральные селекторы на основенизкомолекулярных селекторов и производных полисахаридов, в меньшей степени ̶ белков и макроциклических антибиотиков.

Adsorption of mandelic acid enantiomers on a chiral stationary phase with a grafted antibiotic eremomycin

Adsorption of mandelic acid enantiomers on the Nautilus-E chiral stationary phase with eremomycin as a grafted antibiotic, as influenced upon by composition of the water–ethanol mobile phase, was studied. The surface of the adsorbent was evinced to be heterogeneous and to have two types of adsorption sites: the enantioselective and nonselective ones. Nonselective interactions contribute to adsorption of mandelic acid mainly. With the ethanol fraction in the eluent increased from 40 vol% to 60 vol%, contribution of nonselective interactions to adsorption was increase. The adsorption isotherms of S- and R-mandelic acid were plotted by the Glueckauf method and described by the bi-Langmuir and Henry–Langmuir isotherm models. The Henry–Langmuir model was found out to adequately describe the experimental equilibrium findings in the concentration range under study. The temperature effect on the adsorption equilibrium was discussed. The thermodynamic characteristics of enantioselective adsorption sites were characterized by their adsorption constants, saturation capacities as influenced upon by temperature. A significant increase in the true enantioselectivity at the high-energy adsorption sites with an increase in temperature was revealed. Retention and recognition of mandelic acid enantiomers on the enantioselective adsorption sites were governed by the entropy term.

Effect of the ionic strength of a mobile phase on the chromatographic retention and thermodynamic characteristics of the adsorption of enantiomers of α-phenylcarboxylic acids on a chiral adsorbent with grafted antibiotic eremomycin

The effect the ionic strength of an aqueous ethanol mobile phase containing buffer salt has the on retention and thermodynamics of adsorption of optical isomers of some α-phenylcarboxylic acids on chiral adsorbent Nautilus-E with grafted antibiotic eremomycin is investigated. It is shown that ion exchange processes participate in the adsorption of enantiomers of α-phenylcarboxylic acids. It is established that electrostatic interactions contribute to the retention of enantiomers of α-phenylcarboxylic acids and affect selectivity only slightly. The dependences of retention characteristics, selectivity, and thermodynamic parameters on the concentration of the buffer salt in the eluent are determined. A statistical analysis of enthalpy–entropy compensation is performed, and the compensation effect is shown to be true. It is found that the points corresponding to the investigated adsorbates are distributed over the compensation dependence according to the spatial structural characteristics of molecules.

Simultaneous Liquid Chromatographic Determination of 10 Ultra-Violet Filters in Sunscreens.

A rapid HPLC method was developed for the simultaneous determination of 10 UV filters found in sunscreen. The following UV filters were analyzed in this method; 2-phenylbenzimidazole-5-sulfonic acid, benzophenone-3, isoamyl p-methoxycinnamate, 4-methylbenzylidene camphor, octocrylene, ethylhexyl dimethyl 4-aminobenzoic acid, ethylhexyl methoxycinnamate, butyl methoxydibenzoylmethane, ethylhexyl salicylate and homosalate. The method was developed on two columns; a Thermo Hypersil C18 BDS, 3 µm column (4.6 × 100 mm) and a Chromolith RP-18e Monolithic column (4.6 × 100 mm). The same mobile phase of ethanol and 1% acetic acid (70:30, v/v) was employed for both columns. The separation of the 10 UV filters was carried out successfully on both columns; the optimal resolution was obtained on the Thermo Scientific Hypersil column in a time frame of 7 min. An isocratic elution utilizing ethanol and acetic acid (70:30, v/v) at a temperature of 35°C was employed. The method was applied to a number of commercial samples of sunscreen and lotions and was validated according to International Conference on Harmonisation guidelines for selectivity, linearity, accuracy, precision and robustness. A comparison of the performances of both columns was also carried out.

A Rapid and Green Limit Test Method for Five Synthetic Colorants in Foods Using Polyamide Thin-layer Chromatography

Synthetic food colorants are used in very small amounts. Typically, the colorants are extracted, purified and concentrated prior to analysis; however, sample preparation is time-consuming, of high cost and environmentally unfriendly. In this work, a polyamide thin-layer chromatographic (TLC) method in combination with on-plate solid-phase extraction and backlight-assisted detection has been developed for five commonly used synthetic colorants in foods. Beverages (degassed where appropriate) were directly applied to the polyamide TLC plate. Gelatinous and solid samples were first extracted with water–ammonia aqueous solution (25 %) (99:1) assisted by ultrasonic treatment. Sample solutions were then acidified before application. Relatively large volumes of solution (5–25 μl) could be applied to the plate without significant sample diffusion. Before development, the start spots were cleaned up using ethanol (95 %)–water–acetic acid (5:5:0.1). The plate was developed using a mobile phase of ethanol (95 %)–water–ammonia aqueous solution (25 %) (75:14:1). After development, the plate was viewed in backlight mode with an LED array light. The selectivity of the method proved acceptable. The limits of detection for Ponceau 4R, Amaranth, Tartrazine, Sunset Yellow and Brilliant Blue were 10.1, 9.59, 4.19, 4.12 and 2.06 ng, respectively. The method was rapid, low-cost and sensitive, providing a green limit test method for five colorants in foods.

An Isocratic Toxic Chemical-Free Mobile Phase HPLC-PDA Analysis of Malachite Green and Leuco-Malachite Green

This paper describes a reserved-phase high-performance liquid chromatographic (HPLC) method for detecting malachite green (MG) and leuco-malachite green (LMG) using an isocratic toxic organic solvent/reagent-free mobile phase. Chromatographic separations were performed an Inertsil® WP300 C4 with 0.02 mol/L octane sulfonic acid–ethanol mobile phase and a photodiode-array detector. The total run time was <5 min. The system suitability was well within the international acceptance criteria. A harmless method for simultaneously detecting MG and LMG was developed and may be further applied to the quantification in foods.

Enantiomeric Separations of Chiral Sulfonic and Phosphoric Acids with Barium-Doped Cyclofructan Selectors via an Ion Interaction Mechanism

New cyclofructan-6 (CF6)-based chiral stationary phases (CSPs) bind barium cations. As a result, the barium-complexed CSPs exhibit enantioselectivity toward 16 chiral phosphoric and sulfonic acids in the polar organic mode (e.g., methanol or ethanol mobile phase containing a barium salt additive). Retention is predominantly governed by a strong ionic interaction between the analyte and the complexed barium cation as well as hydrogen bonding with the cyclofructan macrocycle. The log k versus log [X], where [X] = the concentration of the barium counteranion, plots for LARIHC-CF6-P were linear with negative slopes demonstrating typical anion exchange behavior. The nature of the barium counteranion also was investigated (acetate, methanesulfonate, trifluoroacetate, and perchlorate), and the apparent elution strength was found to be acetate > methanesulfonate > trifluoroacetate > perchlorate. A theory based upon a double layer model was proposed wherein kosmotropic anions are selectively adsorbed to the cyclofructan macrocycle and attenuate the effect of the barium cation. van't Hoff studies for two analytes were conducted on the LARIHC-CF6-P for three of the barium salts (acetate, trifluoroacetate, and perchlorate), and the thermodynamic parameters governing retention and enantioselectivity are discussed. Interestingly, for the entropically driven separations, enantiomeric selectivity can increase at higher temperatures, even with decreasing retention.

SEPARATION AND PURIFICATION OF 5 SAPONINS FROM Panax Notoginseng BY PREPARATIVE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

A simple and rapid method for preparative separation of notoginsenoside R1, ginsenosides Re, Rg1, Rb1, and Rd from Panax notoginseng was developed with preparative high-performance liquid chromatography (prep-HPLC). The satisfied chromatographic separation of individual compounds was achieved using a mobile phase of ethanol–water system on an Alltech Alltima C18 column in less than 1 hr. The purity of all 5 saponins obtained was determined to be more than 96% by normalization of the peak area detected by HPLC-UV. Chemical structures of purified products were confirmed by MS and their reference compounds. The results indicated that this method is useful for the preparative-scale separation of notoginsenoside R1, ginsenosides Re, Rg1, Rb1, and Re in a simple, rapid, ease of use, and cost-effective manner.

Enantioselective Analysis of Fluoxetine and Norfluoxetine by LC in Culture Medium for Application in Biotransformation Studies Employing Fungi

A liquid chromatography method is described for the analysis of fluoxetine and norfluoxetine enantiomers in fungi cultures. The analytes were separated simultaneously by LC employing a serial system. The resolution was performed using a mobile phase of ethanol: 15 mM ammonium acetate buffer solution, pH 5.9: acetonitrile (77.5:17.5:5, v/v/v). UV detection was at 227 nm. Hexane: isoamyl alcohol (98:2, v/v) was used as extractor solvent. The calibration curves were linear over the concentration range of 12.5–3,750 ng mL−1 (r ≥ 0.996). The values for intra- and inter-day precision and accuracy were ≤10% for all analytes. The validated method was used to evaluate fluoxetine biotransformation to its mammalian metabolite, norfluoxetine, by selected endophytic fungi. Although the desired biotransformation was not observed in the conditions used here, the method could be used to evaluate the biotransformation of fluoxetine by other fungi or to be extended to other matrices with adequate procedures for sample preparation.

Fractionation of Zein by Size Exclusion Chromatography

Zein is a group of alcohol-soluble corn proteins, which consists of several individual proteins. A single-step gel filtration chromatography method was developed to fractionate individual zeins from ethanol extracts of whole corn. A Superdex prep 75 column was used with different mobile phases to fractionate the zeins, which were analyzed by SDS-PAGE and UV spectrophotometry. With 70% aqueous ethanol as the mobile phase, fractions containing a mixture of alpha-zein/beta-zein and alpha-zein/delta-zein were obtained. With ammonium bicarbonate added to the 70% ethanol mobile phase, it was possible to obtain beta-zein and delta-zein fractions devoid of other proteins. However, all fractions containing alpha-zein also contained minor amounts of delta-zein and/or beta-zein. Almost all fractions also contained non-protein impurities.

Determination of butyl methoxydibenzoylmethane, benzophenone‐3, octyl dimethyl PABA and octyl methoxycinnamate in lipsticks

The complex composition of lipstick formulations usually needs the use of organic solvents for sample dissolution. A treatment based on dissolution of cosmetic samples in ethanol-water (70 : 30, v/v) by use of ultrasonic irradiation is proposed. A C(18) stationary phase and an isocratic mobile phase of ethanol:water:acetic acid (70 : 29.5 : 0.5, v/v/v) with a flow rate of 1 mL min(-1) and an injection volume of 20 microL is proposed for the high-pressure liquid chromatography (HPLC) determination of four UV-filters, and detection was carried out at 309 nm. The limit of the chromatographic detection was 7.0 microg mL(-1) for butyl methoxydibenzoylmethane, 1.5 microg mL(-1) for benzophenone-3, 1.4 microg mL(-1) for octyl dimethyl p-aminobenzoic acid (octyl dimethyl PABA) and 2.7 microg mL(-1) for octyl methoxycinnamate. The relative standard deviations of the results were between 1.8 and 2.4%. The results were comparable to those obtained by a procedure based on the use of tetrahydrofuran. The method can be considered as a green analytical procedure because it only requires the use of small quantities of ethanol.

Speciation of Thulium Porphyrin Complexes by Reversed‐Phase HPLC

Six new thulium porphyrin complexes have been separated by high performance liquid chromatography with triethanolamine (TEOLA) and acetic acid (HAc) as additives in the methanol–water mixture. The function of TEOLA and HAc has been described. The whole analysis was completed on a C18 column in 16 min at a flow rate of 0.5 mL min−1, with the mobile phase of methanol–water (93:7,v:v) containing 75 mmol L−1 TEOLA and 200 mmol L−1 HAc. The detection limits (S/N = 3) of thulium porphyrins at 420 nm were 1.0, 1.0, 1.0, 1.0, 5.0, and 5.0 ng mL−1, respectively. Compared with the methanol system, it can attain the equivalent separation with the mobile phase of ethanol–water (90:10,v:v) containing 25 mmol L−1 TEOLA and 200 mmol L−1 HAc pumped at 0.25 mL min−1.