Research on Formaldehyde Release Rate of Car mats

The environmental test cabin method was used to simulate the actual use environment of car mats to collect test gas, The formaldehyde content in the collected gas was measured by ultraviolet spectrophotometer, and the formaldehyde release rate was calculated. The results indicated that formaldehyde was released in all 30 batches of samples at a rate ranging from 0.02 to 0.13mg/ m2 (m2•h).

Odorant Monitoring in Natural Gas Pipelines Using Ultraviolet–Visible Spectroscopy

The remote, timely and in-field detection of sulfured additives in natural gas pipelines is a challenge for environmental, commercial and safety reasons. Moreover, the constant control of the level of odorants in a pipeline is required by law to prevent explosions and accidents. Currently, the detection of the most common odorants (THT = tetrahydrothiophane; TBM = tertiary butyl mercaptan) added to natural gas streams in pipelines is made in situ by using portable gas chromatography apparatuses. In this study, we report the analysis of the ultraviolet spectra obtained by a customized ultraviolet spectrophotometer, named Spectra, for the in-field detection of thiophane and tertiary butyl mercaptan. Spectra were conceived to accomplish the remote analysis of odorants in the pipelines of the natural gas stream through the adoption of technical solutions aimed to adapt a basic bench ultraviolet spectrophotometer to the in-field analysis of gases. The remotely controlled system acquires spectra continuously, performing the quantitative determination of odorants and catching systemic or accidental variations of the gaseous mixture in different sites of the pipeline. The analysis of the experimental spectra was carried out also through theoretical quantum mechanical approaches aimed to detect and to correctly assign the nature of the intrinsic electronic transitions of the two odorants, thiophane and tertiary butyl mercaptan, that cause the ultraviolet absorptions. So far, these theoretical aspects have never been studied before. The absorption maxima of thiophane and tertiary butyl mercaptan spectra were computationally simulated through the usage of selected molecular models with satisfactory results. The good matches between the experimental and theoretical datasets corroborate the reliability of the collected data. During the tests, unexpected pollutants and accidental malfunctions have been detected and also identified by Spectra, making this instrument suitable for many purposes.

Synthesis and antibacterial activity of modified ε-polylysine

In this paper, Ugi reaction was used to synthesize the modified polylysine (M-ε-PL) in two steps, and OD value was measured by ultraviolet spectrophotometer to determine the inhibitory rate of M-ε-PL in different concentrations of Escherichia coli and Staphylococcus aureus. The results showed that the antibacterial effect was better with the increase of concentration of M-ε-PL. Among them, 20 mg/mL M-εPL had better bacteriostatic effect on E. coli and S. aureus. The antibacterial rate was 70% and 44%.

ANALISIS PENETAPAN KADAR NIPAGIN DALAM SEDIAAN BODY LOTION TIE (TANPA IZIN EDAR) YANG BEREDAR DI PASAR TRADISIONAL KOTA PALU

This study aims to determine the levels of nipagin as preservative in body lotions which have no marketing authorization (MA). Each sample was taken from 4 traditional markets located in Palu City. The assay of nipagin in the body lotions was done by using ultraviolet (UV) at wavelength of 257 nm. From 8 different samples, 5 of them contain nipagin of which levels are as follows: A1 = 0.232%; A2 = 0.229%; B1 = 0.124%; B2 = 0.120%; C1 = 0.120%; C2 = 0.117%; and D1 = 0.267%; D2 = 0.273%; and F1 = 0.213%; and F2 = 0.215%. Based on the results obtained, those body lotions that have no marketing authorization meet the requirement of nipagin’s preservative levels according to Analitical Method of National Center for Drug and Food Testing, in which the allowed levels of nipagin for body lotion is 0.4%.Keywords: Body Lotion, Nipagin, Ultraviolet Spectrophotometer.

Study on the Heat Shrinkable Property of Opaque COC/PETG Film

This paper has studied heat shrinkable properties of COC/PETG blending film with microvoids inside. The shrink curve, shrink force, film structure and light barrier effect were studied by use of electron stretcher, SEM, shrink force tester, ultraviolet spectrophotometer and so on. The results indicated that COC/PETG blending film with many microvoids inside can receive more than 70% shrinkage and lower shrink force by comparing transparent PETG shrink film. At the same time, COC/PETG shrink film has excellent UV-light barrier effect from 310-400nm which also has good visual light barrier effect from 400-800nm because of it 85% opacity and 25% transparency.