Mass Balance Method for Purity Assessment for Pesticide Analytical Standards

Imazamox, a widely used herbicide, is currently managed by the Pesticide MRLs and Positive List System of the Ministry of Food and Drug Safety, and the development of reliable standard materials for analysis is urgently required. To confirm the reliability of the mass balance method, we measured the purity of the imazamox reference material (RM) certified by an RM producer accredited with ISO Guide 34 and estimated measurement uncertainty. According to this method, the content of structurally similar organic impurities was measured using high-performance liquid chromatographic coupled with ultraviolet (HPLC-UV), and the moisture, volatile impurities, and non-volatile impurities were quantitatively analyzed using a thermogravimetric analyzer (TGA). Purity and measurement uncertainty were calculated based on analysis of the HPLC-UV and TGA results obtained, and the validity of these values was confirmed by comparing with the values provided in the RM certificate.

Study of the Alcohol Quality Obtained by Fermentation of Highly Concentrated Grain Wine by Different Races of Yeast

The topicality. Requirements for the quality of ethyl alcohol produced for further use in the production of alcoholic beverages are constantly increasing. This is due to the growing competition of producers of alcoholic beverages (improving the range and quality of products) and the revision of standards for products. New directions in the alcohol technology development require increasing the dry matter concentrations of the wort; fermentation at elevated temperatures and concentrations of alcohol in the brew; ensuring the reduction of the cost of alcohol by saving raw materials and energy resources. In such conditions, highly productive breeds of yeast with increased osmophilicity, thermotolerance and fermentation activity are required. Research related to the search for new strains producers of ethyl alcohol, and the technology development for highly concentrated mash from grain raw materials are relevant issues for the alcohol industry. Purpose and methods. Investigation of the alcoholic yeast races influence on the synthesis of metabolites during fermentation of highly concentrated wort from grain raw materials. For research methods common to the alcohol and alcoholic beverages have been used. Results. The influence of races of alcoholic yeast on the quality indicators of alcohol has been studied. It was found that the selected race of yeast S. cerevisiae DO-16 in the process of life synthesizes significantly fewer side metabolites compared to other studied races DO-11, K-81 and XII. The use of the selected race of S. cerevisiae DO-16 makes it possible to ferment highly concentrated wort from grain raw materials. It has been experimentally proved that at a concentration of DM concentration of the wort 28 %, the selected osmophilic strain of the yeast S. cerevisiae DO-16 provides regulated indicators of the hydrocarbon composition of mature brews and synthesizes up to 14.40 % vol. alcohol, respectively. To improve the qualitative sensory characteristics of ethanol, the possibility of metabolically adjusting the synthesis of volatile alcohol impurities using different races of alcoholic yeast was investigated. Conclusions and discussions. Scientific novelty lies in the selection race for the yeast fermentation of corn mash highly concentrated with reduced alcohol content related impurities. The influence of yeast race on the formation of alcohol metabolites has been studied. The practical significance of the obtained results lies in the industrial implementation of the selected race of alcoholic yeast for fermentation of highly concentrated wort from grain raw materials. Prospects for further research are the possibility of influencing the quality of alcohol as a raw material for high-quality alcoholic beverages. During the fermentation of wort from grain raw materials, the qualitative and quantitative composition of volatile impurities of alcohol largely depends on the race of alcoholic yeast. The results of research on the biosynthesis of volatile impurities of alcohol allow you to adjust the quality of alcohol for the production of high quality alcoholic beverages.

Identification of the Organic Volatile Impurities in Ezitamibe using GC-HS Technique

Ezetimibe prevents intestinal cholesterol synthesis, which in turn reduces the quantity of cholesterol and thereby helps to reduce heart problems and strokes. In the production of ezetimibe, several organic chemical solvents such as methanol, acetone, isopropyl alcohol, dichloromethane, n-hexane, ethyl acetate, tetrahydrofuran, toluene and dimethyl formamide were used. The measurement of residual solvents is necessary for release checks of all drug substances, based on sound manufacturing processes. The analysis of above mentioned nine solvents in ezetimibe drug was investigated using gas chromatographic method employing detection with flame ionization mode. All analyses were performed using ZB-624 column (30 m length × 0.53 mm identification, 3.0 μm thickness film). The column oven temperature flux was managed to maintain for 11 min at 40 ºC and then continued to upsurge to a temperature close of 240 ºC at a rate of 20 ºC/min and retained for 4 min. The flame ionization detector and injector port were managed at 260 and 200 ºC, respectively. Results after the validation of the gas chromatographic method showed the satisfactory linearity, sensitivity, robustness, accuracy, selectivity and precision for the tested organic solvents. This gas chromatographic approach can therefore be exploited in the assessment of studied nine residual chemical solvents for periodic analysis by gas chromatography for samples of ezetimibe drug.

A NOVEL VALIDATED HEADSPACE GAS CHROMATOGRAPHY METHOD FOR THE SIMULTANEOUS QUANTIFICATION OF THREE ORGANIC VOLATILE IMPURITIES IN ENROFLOXACIN PURE AND PHARMACEUTICAL DOSAGE FORMS

Objective: This article describes a novel, simple, and rapid gas chromatographic method for quantification of three organic volatile impurities (OVIs) present in enrofloxacin and its pharmaceutical dosage forms. Methods: As stationary phase using ZB-624 30 m×0.53 mm, 3.0 μ column with flame ionized detector at 250°C. The injector temperature is maintained at 180°C. The nitrogen gas was used as a carrier gas with a flow rate of 4.0 mL/min. The method involved a thermal gradient elution. The total run time is 21.14 min. Results: The retention time of three OVIs taken individually and in spiked standard solutions were determined. The retention times are 2.30 min for methanol, 7.07 min for 1-butanol, and 8.48 min for toluene, respectively. The % relative standard deviation for six injections should be not more than 10%. The % recovery ranges from 85 to 115%. The correlation coefficient (r2) for linearity is not <0.99. The limit of quantification was found to be 260 ppm for methanol, 101 ppm for 1-butanol, and 56 ppm for toluene. Furthermore, verified precision, ruggedness, robustness, solution stability, and pharmaceutical analysis. Conclusion: All the obtained results are found within the acceptable limits. The proposed method has been successfully applied for the quantification of OVIs present in enrofloxacin pure and its pharmaceutical dosage forms.