Purpose:The aim of this study was to isolate and identify the active compound antioxidant fractions from Gardenia jasminoides Ellis leaves. Research Method:The antioxidant activity was determined using DPPH 0.1 mM (1:1), and was analyzed spectrophotometrically. In addition, separation was performed using column chromatography. The most active isolate was identified by UV-Vis, FT-IR, and LC-MS/MS. The quantitative analysis was done in three replicated.Findings: It was discovered that the antioxidant activity in the semi-polar fraction (IC 50 = 62,50 ppm) was higher than both the polar and non-polar fractions. Combining 295 isolates via column chromatography, 11 combined isolates were obtained (fA-fK). The fK isolate had the highest antioxidant activity of 90.38% and IC 50 15.74 ppm. It also obtained 2 maximum wavelengths (336 and 275 nm) and could be categorised as flavonoid . The FTIR analysis also showed that the fK isolate had functional groups found in flavonoid. Finally, the identification of the fK isolate by LC-MS/MS showed that the compound at retention times of 5,91 and 5,06 minutes were kaempferol 3-O-rutinoside and rutin, respectively.Originality/ Value: Based on the obtained results, it was concluded that GJE leaves have the potential to be developed as a new and inexpensive source of flavonoids.

Telah dilakukan Penelitian tentang pengukuran temperatur plasma dengan menggunakan metode pendekatan  Persamaan Boltzmann. Penelitian dilakukan dengan menggunakan Instrumen Laser-Induced Breakdown Spectroscopy (LIBS) di Laboratorium Penelitian Terpadu FMIPA Universitas Udayana. Perhitungan temperatur plasma dilakukan dengan Persamaan Boltzmann menggunakan intensitas emisi dan luas area dibawah kurva dari emisi dua panjang gelombang atom netral Cu I 521,82 nm dan Cu I 510,55 nm. Data intensitas emisi atom netral Cu diperoleh dengan memfokuskan laser Nd-YAG (1064 nm, 7 ns) dengan energi 80 mJ ke permukaan lempengan sampel Bras 6s (atau 99,99%), pada lingkungan udara 1 atm dan lingkungan gas Helium dengan laju aliran 60 mL/s. Emisi foton dari atom-atom netral Cu dalam plasma ditangkap oleh spektrometer HR 2500+ (14.336 CCD pixel, 200-800 nm) dengan variasi waktu tunggu deteksi dari 0 µs sampai 1,5 µs. Dengan menggunakan persamaan Boltzmann diperoleh temperatur rata-rata plasma pada rentang waktu tunggu deteksi tersebut pada lingkungan udara sebesar (8976,40±160,34) K melalui perbandingan intensitas dan (13119,20±435,23) K menggunakan perbandingan luas area. Temperatur rata-rata plasma pada lingkungan gas Helium diperoleh sebesar (12261,21±419,06) K dengan perbandingan intensitas dan (16882,41± 678,18) K menggunakan perbandingan luas area.