De-masking of magnesium—acetylacetonate complex for direct ethylenediaminetetraacetic acid titration of calcium and magnesium in the same solution and at the same pH

The Analyst ◽  
1993 ◽  
Vol 118 (7) ◽  
pp. 905-907 ◽  
Author(s):  
Dipali Kundu ◽  
S. K. Roy
1959 ◽  
Vol 37 (1) ◽  
pp. 225-229 ◽  
Author(s):  
H. M. Czajkowska Robinson ◽  
J. C. Rathbun

A rapid ethylenediaminetetraacetic acid titration for calcium and magnesium in serum requiring 0.1 ml of blood is described. Eriochrome black T is used as the sole indicator and the end point is observed photometrically. After determination of total calcium and magnesium, the calcium is removed as oxalate, the magnesium determined separately, and the calcium obtained by difference. The method is highly reproducible and is sensitive to ± 0.1 mg% of either calcium or magnesium.


1959 ◽  
Vol 37 (2) ◽  
pp. 225-229 ◽  
Author(s):  
H. M. Czajkowska Robinson ◽  
J. C. Rathbun

A rapid ethylenediaminetetraacetic acid titration for calcium and magnesium in serum requiring 0.1 ml of blood is described. Eriochrome black T is used as the sole indicator and the end point is observed photometrically. After determination of total calcium and magnesium, the calcium is removed as oxalate, the magnesium determined separately, and the calcium obtained by difference. The method is highly reproducible and is sensitive to ± 0.1 mg% of either calcium or magnesium.


1964 ◽  
Vol 12 (01) ◽  
pp. 179-200 ◽  
Author(s):  
Torstein Hovig

SummaryThe effect of calcium and magnesium on the aggregation of rabbit blood platelets in vitro was studied, with the following results:1. Platelet aggregation induced by ADP or collagen could be prevented by EGTA or EDTA. The aggregating effect was restored by recalcification. The effect was also restored by addition of magnesium in EDTA-PRP, but not in EGTA-PRP unless a surplus of calcium was present.2. Calcium remained in concentrations of the order of 0.15–0.25 mM after dialysis or cation exchange of plasma. Aggregation of washed platelets resuspended in such plasma could not be produced with ADP or collagen, unless the calcium concentration was increased or that magnesium was added.3. The adhesiveness of blood platelets to collagen was reduced in EGTA-PRP and EDTA-PRP. Release of ADP from platelets influenced by collagen could not be demonstrated either in EGTA-PRP (presence of magnesium) or in EDTA-PRP.4. It is concluded that calcium is a necessary factor both for the reaction leading to release of ADP and for the the aggregation produced by ADP.5. Thrombin induced aggregation of washed platelets suspended in tris-buffered saline in the presence of calcium. No effect of magnesium could be observed unless small quantities of calcium were present.


1962 ◽  
Vol 21 (4) ◽  
pp. 798-803 ◽  
Author(s):  
Keith J. Smith ◽  
Walter Woods

2019 ◽  
Author(s):  
Marc Blétry

Henderson-Hasselbalch relation is generally the simplified theoretical framework used to introduce students to acid-base titration. However, it is not always valid and its limitations should be made clear to chemistry students. The appropriate parameter to evaluate its validity is K a /C 0 , in connection with Ostwald dilution law. For more advanced students, it is possible to deduce analytical expressions that always fit accurately acid-base titrations and allow an evaluation of Henderson Hasselbalch relation. Gran plot appears as a particularly sensitive technique to the breakdown of Henderson Hasselbalch relation.


2019 ◽  
Vol 31 (1) ◽  
pp. 48-51
Author(s):  
Suha S Hassan ◽  
Nidhal H. Ghaib ◽  
Batool H Al-Ghurabi

Background: The microorganisms can impend the life of health care professional and particularly the dental practitioners. They can be transmitted by different ways like airborne and droplet transmission. The current study was carried out to identify whether the arch wires that received from the manufactures are free from microbial contamination and to determine the bacterial species attached to the arch wires. Materials and Methods: This study involved eighty samples, consisted of two types of arch wires (nitinol and stainless-steel) from four companies (3M, G&H, Jiscop, OrthoTechnology). These wires inserted in a plane tube that contains 10 -ml of (Tris [tris(hydroxymethyl)aminomethane] and EDTA (ethylenediaminetetraacetic acid) tris-EDTA and brain heart infusion (BHI) broth. A 0.1 ml was withdrawn from the tube and spread on agar plates. The control groups consist of 16 plane tube (8 tubes with tris-EDTA and other 8 tubes with (BHI). Results: Microbial sampling yielded growth from 5 of the 80 arch wires. The predominant bacteria that isolated were Bacillus spp. No growth was recovered from 75 of the samples and from controls. The bacteria were isolated by BHI reagent and no growth was observed by tris-EDTA reagent with statistically significant difference (P<0.05). The Bacillus spp. found only in the G&H and Jiscop companies, however, no statistically significant difference was found among them (P>0.05). With regard to the presence and distribution of bacteria according to the types of wires, the present results clarified that cases of contamination with Bacillus spp. were found in the nitinol arch wires with statistically significant difference (P<0.05). Conclusions: The results of the current study revealed low count of bacterial contamination in the two types of companies (G&H and Jiscop). Not all materials that received from the manufactures are free from contamination and an effective sterilization regimen is needed to avoid cross-contamination.


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