Determination of Free and Bound Cd, Zn, Cu, and Ag Ions in Lobster (Homarus americanus) Digestive Gland Extracts by Gel Chromatography Followed by Atomic Absorption Spectrophotometry and Polarography

1993 ◽  
Vol 76 (4) ◽  
pp. 794-798 ◽  
Author(s):  
Chiu L Chou ◽  
John F Uthe ◽  
Robert D Guy
Keyword(s):  
Molecular Weight ◽  
Metal Ions ◽  
Atomic Absorption ◽  
Gel Permeation Chromatography ◽  
Weight Fraction ◽  
Atomic Absorption Spectrophotometry ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Absorption Spectrophotometry ◽  
Gel Permeation

Abstract Gel-permeation chromatography followed by atomic absorption spectrophotometric and polarographic analyses were used to measure free and bound divalent metal ions in lobster digestive gland extracts prepared with or without oc-toluenesulfonyl fluoride, a protease inhibitor. Chromatography on Sephadex G-50 or G-100 yielded 3 UV-absorbing peaks, which corresponded, respectively, to the void volume, a medium molecular weight fraction, and a low molecular weight fraction that contained free divalent metal ions. In protease-inhibited extracts, only Zn+2 was found, whereas Cd, Cu, and Ag were bound in high and medium molecular weight fractions. Cd+2 and Zn+2 were rapidly released from their bound forms in the absence of a protease inhibitor, and their presence was confirmed by polarography with EDTA. Gel-permeation chromatography coupled with atomic absorption spectrophotometry offers a rapid method for following changes in the concentrations of bound and free metal ions during processing of shellfishbased foodstuffs.

scholarly journals The liver cell plasma membrane Ca2+ inflow systems exhibit a broad specificity for divalent metal ions

1990 ◽  
Vol 269 (3) ◽  
pp. 579-587 ◽  
Author(s):  
J N Crofts ◽  
G J Barritt
Keyword(s):  
Angiotensin Ii ◽  
Metal Ions ◽  
Atomic Absorption ◽  
Absorption Spectroscopy ◽  
Divalent Cation ◽  
Atomic Absorption Spectroscopy ◽  
Plasma Membranes ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Broad Specificity

1. The inflow of Mn2+ across the plasma membranes of isolated hepatocytes was monitored by measuring the quenching of the fluorescence of intracellular quin2, by atomic absorption spectroscopy and by the uptake of 54Mn2+. The inflow of other divalent metal ions was measured using quin2. 2. Under ionic conditions which resembled those present in the cytoplasmic space, Mn2+, Zn2+, Co2+, Ni2+ and Cd2+ each quenched the fluorescence of a solution of Ca2(+)-quin2. 3. The addition of Mn2+, Zn2+, Co2+, Ni2+ or Cd2+ to cells loaded with quin2 caused a time-dependent decrease in the fluorescence of intracellular quin2. Plots of the rate of decrease in fluorescence as a function of the concentration of Mn2+ reached a plateau at 100 microM-Mn2+. 4. The rate of decrease in fluorescence induced by Mn2+ was stimulated by 20% in the presence of vasopressin. The effect of vasopressin was completely inhibited by 200 microM-verapamil. Adrenaline, angiotensin II and glucagon also stimulated the rate of decrease in the fluorescence of intracellular quin2 induced by Mn2+. 5. The rate of decrease in fluorescence induced by Zn2+, Co2+, Ni2+ or Cd2+ was stimulated by between 20 and 190% in the presence of vasopressin or angiotensin II. 6. The rates of uptake of Mn2+ measured by atomic absorption spectroscopy or by using 54Mn2+ were inhibited by about 20% by 1.3 mM-Ca2+o and stimulated by 30% by vasopressin. 7. Plots of Mn2+ uptake, measured by atomic absorption spectroscopy or with 54Mn2+, as a function of the extracellular concentration of Mn2+ were biphasic over the range 0.05-1.0 mM added Mn2+ and did not reach a plateau at 1.0 mM-Mn2+. 8. It is concluded that (i) hepatocytes possess both a basal and a receptor-activated divalent cation inflow system, each of which has a broad specificity for metal ions, and (ii) the receptor-activated divalent cation inflow system is the receptor-operated Ca2+ channel.

Functionality Distribution of Hydroxyl-Terminated Polybutadienes by Gel Permeation Chromatography. I. Method and Calibration Procedure

1976 ◽  
Vol 49 (5) ◽  
pp. 1238-1249
Author(s):  
J. N. Anderson ◽  
S. K. Baczek ◽  
H. E. Adams ◽  
L. E. Vescelius
Keyword(s):  
Molecular Weight ◽  
Near Infrared ◽  
Gel Permeation Chromatography ◽  
Weight Fraction ◽  
Calibration Procedure ◽  
Double Bonds ◽  
Molecular Weight Distributions ◽  
Fractionation Procedure ◽  
Gel Permeation

Abstract In recent years, considerable attention has been focused on the structural characterization of functionally terminated hydrocarbon prepolymers used in propellant binders and other applications. The molecular weight averages and molecular weight distributions of hydroxyl-and carboxyl-terminated poly butadienes have been determined by gel permeation chromatography (GPC). The functionality distribution of these prepolymers has also been previously studied by column fractionation and a procedure combining GPC and column fractionation of the polymer by stepwise elution from silica gel. The carboxyl or hydroxyl equivalent weights of the fractions were determined by infrared or near-infrared spectroscopy. The fractionation procedure is quite laborious, and multiple peaks were observed in the elution profile, making it difficult to decide how the fractions were to be grouped for subsequent analysis. Previously, a technique for determining the distribution of unsaturation in copolymers containing a small number of double bonds as a function of GPC elution volume was developed. The technique utilized a GPC equipped with uv photometer and differential refractometer detectors to determine the ratio of the weight fraction of olefinic bonds to the weight fraction of polymer by GPC analysis of the polymer after derivatization of the double bonds with 2,4-dinitrobenzenesulfenyl chloride. It was suggested that the technique should be applicable for the determination of the distribution of other functional groups with the choice of suitable reagents for derivatization. The purpose of this investigation was to attempt to extend our previous study to simultaneously determine the molecular weight averages, molecular weight distribution, hydroxyl equivalent weight, functionality averages, and functionality distribution of hydroxyl-terminated polybutadienes by a GPC technique.

Interaction of divalent metal ions with the NADP+-malic enzyme from maize leaves

1991 ◽  
Vol 81 (4) ◽  
pp. 462-466 ◽  
Author(s):  
Maria Fabiana Drincovich ◽  
Alberto A. Iglesias ◽  
Carlos S. Andreo
Keyword(s):  
Metal Ions ◽  
Malic Enzyme ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Maize Leaves

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.

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