English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Sodium dehydroacetate (SDA) was extracted from cosmetic powders using a Na2CO3-methanol-H2O system. After the extract was neutralized, the resulting dehydroacetic acid (DAA) reacted with 4-nitrophenylhydrazine∙HCl (4-NPH∙HCl) to give the corresponding hydrazone, which was determined by an HPLC-VIS (400 nm) system. Using 4-NPH∙HCl in great excess was suitable for detecting the presence of DAA, which almost reacted with the hydrazine to yield the corresponding hydrazone. As a result, it was determined that contaminants in the cosmetic powder did not interfere with analysis of the hydrazone. Importantly, the molar absorptivity of the hydrazone (1.29 × 104 at 400 nm) is five times that of DAA (2.57 × 103 at 230 nm). Accordingly, detection of the hydrazone at 400 nm in a new analytical method might have fivefold higher sensitivity compared with that of DAA at 230 nm in the standard method.

chromatography

Facile and Accurate Analysis of Sodium Dehydroacetate in Cosmetic Powders After Extraction by Na&lt;sub&gt;2&lt;/sub&gt;CO&lt;sub&gt;3&lt;/sub&gt;-Methanol-H&lt;sub&gt;2&lt;/sub&gt;O and Derivatization with 4-Nitrophenylhydrazine∙HCl