Comparison of three different analytical protocols for 2019 updated D2425 method for renewable jet fuel product certification analysis.

ASTM standard specification D7566 covers the manufacture of synthetic aviation turbine fuel components and their blends with conventional Jet fuel (Jet A or Jet A-1). One of the components is renewable jet fuel (RJF) which is synthetic paraffinic kerosene (SPK) made from hydroprocessed esters and fatty acids (HEFA). The specification D7566 dictates property requirements for the SPK-HEFA, including concentration limits for selected hydrocarbon types (paraffins, cycloparaffins, and aromatics), which are analyzed by using the mass spectrometry (MS) based standard method D2425. The most recent update for D2425 released in 2019 includes the synthetic hydrocarbon sample type (e.g., SPK-HEFA) and defines various analytical procedures for the analysis. Notably, the procedures differ considerably from each other, and the experimental conditions are not defined in details. This leads to laboratories setting up analytical schemes for D2425 that are likely to differ from each other, which may result in variation in the quality of the results obtained in different laboratories. In the present study, the performances of D2425 analytical protocols set up by three laboratories were tested in certification analysis (D7566) of SPK-HEFA type RJF. The tested analytical protocols were proven to comply with the requirements of the 2019 version of the D2425 standard. Furthermore, the precisions of the protocols did not differ significantly from each other. However, a significant bias was found for the results obtained for cycloparaffins and aromatics. Further, considerable differences were found in the bias values between the laboratories. Based on the results of this study, the guidelines of the 2019 updated D2425 standard may result in setting up an analytical protocol for D2425 which may not be optimal for RJF certification.

Simultaneous analysis of volatile and semi-volatile components in a topical formulation by gas chromatography using a programmed temperature vaporization inlet and flame ionization detection.

Topical formulations are medications applied locally on the skin to treat ailment. They are made up of complex mixtures of active ingredients and excipients. Till date, no analytical method has been found in literature that is able to simultaneously analyze volatile and semi-volatile actives present in topical formulations. In this work, an analytical procedure by gas chromatography equipped with a programmed temperature vaporizing (PTV) inlet and a flame ionization detector was developed and validated for the simultaneous quantitative determination of volatile and semi-volatile actives such as camphor, L-menthol, methyl salicylate, ethyl salicylate, salicylic acid, glycol monosalicylate and capsaicin in a topical formulation. Liquid-liquid extraction was used to isolate the components of interest prior to injection into the gas chromatographic system. All target analytes were completely separated from each other and a linear calibration curve was achieved for all analytes with a determination coefficient > 0.995. 2-phenoxyethanol was used as internal standard for quantitation. Good repeatability and recovery values were achieved and reported. This method reports for the first time, the simultaneous quantitative analysis of volatile and semi-volatile active pharmaceutical ingredients in a single measurement. The developed method was successfully applied to the analysis of real pharmaceutical samples and the described analytical protocols can be recommended for routine analysis of both volatile and semi-volatile actives in the topical formulation.