scholarly journals 3,4-Dihydroxyphenylacetate 2,3-dioxygenase from Klebsiella pneumoniae, a Mg2+-containing dioxygenase involved in aromatic catabolism

1994 ◽  
Vol 301 (1) ◽  
pp. 145-150 ◽  
Author(s):  
A Gibello ◽  
E Ferrer ◽  
M Martín ◽  
A Garrido-Pertierra
Keyword(s):  
Klebsiella Pneumoniae ◽  
Atomic Absorption ◽  
Quaternary Structure ◽  
Atomic Absorption Spectrophotometry ◽  
Ring Cleavage ◽  
Plasma Emission ◽  
Metal Analysis ◽  
First Report ◽  
Absorption Spectrophotometry ◽  
Tetrameric Form

3,4-Dihydroxyphenylacetate 2,3-dioxygenase, an extradiol-ring-cleavage dioxygenase, has been purified from Klebsiella pneumoniae to homogeneity. The enzyme has an M(r) of 102,000 in its tetrameric form with an M(r) of 25,500 for each subunit. Unlike most other dioxygenases, the enzyme reported here contains Mg2+, as determined by atomic-absorption spectrophotometry and plasma emission metal analysis. The enzyme was shown to contain approx. 1 g-atom of Mg2+/mol of protein and we suggest an alpha 4 Mg2+ quaternary structure. This is the first report of a dioxygenase containing Mg2+ in its structure.

DC Arc Plasma Emission Spectrometric Determination of Boron in Plants

1978 ◽  
Vol 61 (3) ◽  
pp. 504-505
Author(s):  
James R Melton ◽  
William L Hoover ◽  
Patricia A Morris ◽  
Janette A Gerald
Keyword(s):  
Atomic Absorption ◽  
Alkali Metals ◽  
Atomic Absorption Spectrophotometry ◽  
Plasma Emission ◽  
Arc Plasma ◽  
Emission Method ◽  
Absorption Spectrophotometry ◽  
Dc Arc

Abstract A dc arc plasma emission method is described for determining boron in plants at levels of ≧2.5 ≧g/g. The sample is wet-digested and analyzed at 2497.73A. Lithium is added to mask enhancement of emission by other alkali metals. Results for boron determined by the described method and atomic absorption spectrophotometry compared favorably. Recoveries of boron added to plants ranged from 90.4 to 104.4% with a mean recovery of 99.7%. The described method is convenient, rapid, and accurate for determining boron in plants.

Analysis of Lead Heavy Metal (Pb) Contamination on Matte Lipstick Preparations for Sale in Banda Aceh City Aceh Market

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Rizki Andalia ◽  
Mulia Aria Suzanni ◽  
Rini Rini
Keyword(s):  
Heavy Metal ◽  
Atomic Absorption ◽  
Atomic Absorption Spectrophotometry ◽  
The Body ◽  
Permissible Limit ◽  
The Sun ◽  
Absorption Spectrophotometry ◽  
Pb Contamination ◽  
Body Organ ◽  
Banda Aceh

Lipstick or lip dye is a cosmetic dose that serves to coloring, decorative the lips, as a moisturizing material and protect the lips from exposure the sun to provide optimum results. Lipstick should not contain chemicals such as lead (Pb) because the Pb is a heavy metal that is very dangerous when continuously used on the skin, because it will be absorbed into the blood and attack the body organ causing the onset of disease. According to BPOM that the lead rate on the lipstick does not exceed the permissible limit of 20 mg/kg or 20 ppm.This research aims to know the levels contained in the samples are 4 brands of matte lipstick that are sold in the Aceh market in Banda Aceh City with the method of atomic absorption spectrophotometry (AAS). The results showed that on the 4 brands of lipstick matte contain heavy metal lead (Pb) with a rate still qualified allowed by BPOM  is samples A, B, C, and D, respectively at 0.24 ppm; 0.10 ppm; 2.87 ppm and 1.32 ppm, so that the 4 brands of lipstick matte are still used.

PENURUNAN KONSENTRASI LOGAM Pb2+ DAN Cd2+ PADA LIMBAH CAIR INDUSTRI SASIRANGAN DENGAN METODE FITOREMEDIASI

2015 ◽  
Vol 1 (1) ◽  
pp. 41
Author(s):  
Bella Santa Rossi ◽  
Paryanti Paryanti ◽  
Yuli Ristianingsih ◽  
Abubakar Tuhuloula
Keyword(s):  
Atomic Absorption ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Spectrophotometry

Pewarnaan pada proses produksi kain sasirangan menghasilkan limbah yang mengandung logam berat, diantaranya adalah timbal (Pb2+) dan kadmium (Cd2+). Penelitian ini bertujuan untuk mengetahui pengaruh proses fitoremediasi terhadap konsentrasi logam Pb2+ dan Cd2+ dari limbah cair industri sasirangan di Kalimantan Selatan, serta mengetahui pertambahan berat basah eceng gondok. Eceng gondok yang sudah dibersihkan dan diaklimatisasi ditanam dalam reaktor berisi larutan limbah dengan konsentrasi 3% (v/v); 9% (v/v); dan 15% (v/v). Sampel diambil setiap 2 hari sekali sebanyak 100 ml dan dianalisis menggunakan AAS (Atomic Absorption Spectrophotometry). Hasil penelitian ini menunjukkan bahwa konsentrasi logam Pb2+ dan Cd2+ dalam limbah setelah proses fitoremediasi terjadi penurunan. Kadar Pb2+ pada konsentrasi 3% (v/v) semula 0,197 ppm menjadi 0,062 ppm, pada konsentrasi 9% (v/v) semula 0,200 ppm menjadi 0,077 ppm dan untuk 15% (v/v) adalah 0,225 ppm menjadi 0,093 ppm. Sedangkan untuk Cd2+ konsentrasi 3% (v/v) semula 0,110 ppm menjadi 0,059 ppm, konsentrasi 9% (v/v) adalah 0,127 ppm menjadi 0,045 ppm dan untuk konsentrasi 15% (v/v) semula 0,144 ppm menjadi 0,047 ppm.

Determination of Minor Nutrients in Fertilizers by Atomic Absorption Spectrophotometry: Second Collaborative Study

1965 ◽  
Vol 48 (6) ◽  
pp. 1100-1103
Author(s):  
C H Mcbride
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Method ◽  
Atomic Absorption Method ◽  
Absorption Spectrophotometry ◽  
Minor Nutrients

Abstract The atomic absorption method studied last year was re-examined and extended to include calcium and sodium. The procedures were submitted to 16 collaborators for determination of Ca, Cu, Fe, Mg, Mn, Na, and Zn. Results for Ca and Na were discouraging; further study is recommended.

Comparison of Methods for Determining Biuret in Urea

1979 ◽  
Vol 62 (1) ◽  
pp. 153-159
Author(s):  
Luis F Corominas ◽  
Victor M Boy ◽  
Manuel Guijosa
Keyword(s):  
Atomic Absorption ◽  
Spectrophotometric Determination ◽  
Atomic Absorption Spectrophotometry ◽  
International Organization ◽  
Comparison Of Methods ◽  
Definite Advantage ◽  
Absorption Spectrophotometry ◽  
Alternative Procedures ◽  
Aoac Method

Abstract The official first action AOAC method for the spectrophotometric determination of biuret in urea, 2.072—2.074, was compared with official first action AOAC method 2.C01-2.C03 (atomic absorption spectrophotometry), 2 simplified versions of 2.072-2.074, and modified versions of 2 alternative procedures of the International Organization for Standardization. Three synthetic urea samples (0.3, 1.4, and 3.0% biuret) and 1 commercial urea sample (1.0% biuret) were analyzed. The methods proved to be equivalent and none showed a definite advantage over 2.072-2.074. The purification of biuret and the interference by ammonia are also discussed.

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