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Solubilities of trace copper and lead species and the complexing capacity of river water in the Linggi River Basin

Tan WT, Tan GS, Nather Khan IS

Environ Pollut, 1988;52(3):221-35.
PMID: 15092608

Chemical forms of copper and lead in river water of the Linggi River Basin have been fractionated into ASV labile, moderately labile, slowly labile, and inert metal species, based on a previously proposed scheme. Free (hydrated) metal ions were identified by a potentiometric method using an ion selective electrode. Speciation results showed that the soluble copper and lead species occurred mainly in the moderately labile and slowly labile fractions. The speciation results are primarily interpreted in terms of organic interaction due to agricultural based and light industries, and urban discharges. The measured metal complexing capacity (MCC) of the samples reveals consistency of the results with the nature of the discharge. MCC correlates reasonably well with the value from the permanganate test on the river water. In general, the speciation pattern was found to be consistent with the findings of other workers.

Matched MeSH terms: Ion-Selective Electrodes
Development of prototype heterogeneous chitosan membrane using different plasticizer for glutamate sensing

Isa IM, Ab Ghani S

Talanta, 2007 Jan 15;71(1):452-5.
PMID: 19071326 DOI: 10.1016/j.talanta.2006.04.034

This paper describes the preparation of and experimentation undertaken by heterogeneous chitosan membrane as ion selective electrode for glutamate ion. The linearity response was obtained in the range of 1.0x10(-5) to 1.0x10(-1)M with a detection limit of 1.0x10(-6)M. The performance of the electrode was found in the pH range of 4.0-8.0 at temperature 25+/-3 degrees C. The response time was at 5-35s and was useful for a period of more than 4 months. The selectivity values towards some anions indicates good selectivity over a number of interfering anions. No significant improvement of membrane performance over additional of plasticizers such as 2-NPOE, BEHA and DOPP. The electrodes gave sufficient Nernstian responses with the exception of membrane with 2-NPOE.

Matched MeSH terms: Ion-Selective Electrodes
Evaluation of the analytical performance of a portable ion-selective electrode meter for measuring whole-blood, plasma, milk, abomasal-fluid, and urine sodium concentrations in cattle

Megahed AA, Hiew M, Grünberg W, Trefz FM, Constable PD

J Dairy Sci, 2019 Aug;102(8):7435-7444.
PMID: 31202658 DOI: 10.3168/jds.2018-16198

A portable ion-selective electrode (ISE) meter (LAQUAtwin B-722; Horiba Instruments Inc., Irvine, CA) is available for measuring the sodium ion concentration ([Na]) in biological fluids. The objective of this study was to characterize the analytical performance of the ISE meter in measuring [Na] in whole-blood, plasma, milk, abomasal fluid, and urine samples from cattle. Method comparison studies were performed using whole-blood and plasma samples from 106 sick calves and 11 sick cows admitted to a veterinary teaching hospital, 80 milk and 206 urine samples from 16 lactating Holstein-Friesian cows with experimentally induced free water, electrolyte, and acid-base imbalances, and 67 abomasal fluid samples from 7 healthy male Holstein-Friesian calves fed fresh milk with or without an oral electrolyte solution. Deming regression and Bland-Altman plots were used to determine the accuracy of the meter against reference methods. The meter used in direct mode on undiluted samples measured whole-blood [Na] 9.7 mmol/L (7.3%) lower than a direct ISE reference method and plasma [Na] 16.7 mmol/L (12.7%) lower than an indirect ISE reference method. The meter run in direct mode measured milk [Na] 3.1 mmol/L lower and abomasal fluid [Na] 9.0% lower than indirect ISE reference methods. The meter run in indirect mode on diluted samples accurately measured urine [Na] compared with an indirect ISE reference method. We conclude that, after adjustment for the bias determined from Bland-Altman plots, the LAQUAtwin ISE meter provides a clinically useful and low-cost cow-side instrument for measuring [Na] in whole blood, plasma, milk, and abomasal fluid.

Matched MeSH terms: Ion-Selective Electrodes*
Chloroquine polymeric membrane electrodes: Development and applications

Saad B, Kanapathy K, Ahmad MN, Hussin AH, Ismail Z

Talanta, 1991 Dec;38(12):1399-402.
PMID: 18965315

Three main types of PVC solvent polymeric membrane ion-selective electrodes for chloroquine are described. They are based on three ion-pairing agents namely dipicrylamine (DPA), tetraphenylborate (TPB) or tetrakis(4-chlorophenyl)borate (TCPB) with either dioctylphenyl phosphonate (DOPP) or trioctyl phosphate (TOP) solvent mediator. All electrodes exhibit Nernstian responses, fast dynamic response times and a wide useful pH range. The best all-round electrode is based on TPB and TOP plasticizing solvent mediators with a limit of detection of 7.1 x 10(-6)M and was utilized for the assay of chloroquine in tablets. Direct potentiometric determinations with either the analyte addition method or the normal calibration method gave results comparable to the official method.

Matched MeSH terms: Ion-Selective Electrodes
Fulltext A laboratory study of fluoride concentration in infant formulas marketed in Malaysia and estimation of daily intake

Mohd Desa, S. N. F., Muhamad, N. A., Mohd Nor, N. A., Abdul Razak, F., Abdul Manan, N. S., Abdul Manan, N. S., et al.

International Food Research Journal, 2020;27(5):893-902.
MyJurnal

The window of maximum susceptibility for the development of dental fluorosis for anterior
teeth is during the first two to three years of life. The primary source of fluoride intake for
infants at this age is mainly from the diet including infant formula. Thus, the present work
aimed to investigate the fluoride concentration in commercially available Malaysian infant
formulas that required reconstitution before consumption. A total of 29 infant formulas available in the Malaysian market were reconstituted with deionised water, fluoridated tap water,
and filtered tap water. The fluoride concentration of the infant formulas was analysed directly
using a fluoride ion selective electrode. The daily fluoride intake estimation from the infant
formulas was calculated using the median infant body weight and recommended volumes for
formula consumption from newborn to > 12 months of age. Results showed that the fluoride
concentration of the infant formulas when reconstituted with deionised water ranged between
0.009 to 0.197 mg/L that contributed to the estimated daily fluoride intake ranging from 0.005
to 0.100 mg (total intake per day) or 0.001 to 0.025 mg/kg (total intake per body weight/day).
The fluoride concentration in the selected infant formulas was low, but after reconstitution
with fluoridated tap water, the overall fluoride concentration in infant formulas sample significantly increased (p < 0.001). Nevertheless, the estimated daily fluoride intake from infant
formulas alone did not exceed the lowest-observed-adverse-effect level (LOAEL) of fluoride
at 0.10 mg/kg/day.

Matched MeSH terms: Ion-Selective Electrodes
Fulltext Titanium (III) cation selective electrode based on synthesized tris(2pyridyl) methylamine ionophore and its application in water samples

Rezayi M, Karazhian R, Abdollahi Y, Narimani L, Sany SB, Ahmadzadeh S, et al.

Sci Rep, 2014;4:4664.
PMID: 24722576 DOI: 10.1038/srep04664

The introduction of low detection limit ion selective electrodes (ISEs) may well pave the way for the determination of trace targets of cationic compounds. This research focuses on the detection of titanium (III) cation using a new PVC-membrane sensor based on synthesized tris(2pyridyl) methylamine (tpm) ionophore. The application and validation of the proposed sensor was done using potentiometric titration, inductively coupled plasma atomic emission spectrometry (ICP-AES), and atomic absorption spectrometry (AAS). The membrane sensor exhibited a Nernstian response to the titanium (III) cation over a concentration range of 1.0 × 10(-6)-1.0 × 10(-2) M and pH range from 1-2.5. The Nernstian slope, the lower of detection (LOD), and the response time (t95%) of the proposed sensor were 29.17 ± 0.24 mV/dec, 7.9 × 10-7 M, and 20 s, respectively. The direct determination of 4-39 μg/ml of titanium (III) standard solution showed an average recovery of 94.60 and a mean relative standard deviation of 1.8 at 100.0 μg/ml. Finally, the utilization of the electrodes as end-point indicators for potentiometric titration with EDTA solutions for titanium (III) sensor was successfully carried out.

Matched MeSH terms: Ion-Selective Electrodes
Electro polymerized 4-vinyl pyridine on 2B pencil graphite as ionophore for cadmium (II)

Wee Ling JL, Khan A, Saad B, Ab Ghani S

Talanta, 2012 Jan 15;88:477-83.
PMID: 22265529 DOI: 10.1016/j.talanta.2011.11.018

A new poly(4-vinyl pyridine) (P4VP) based cadmium (Cd)-ion selective electrode (ISE) was developed. The 4-vinyl pyridine (4VP) was first polymerized electrochemically on the surface of graphite, later characterized by FTIR, SEM/EDX and then optimized as ISE for Cd. At optimal pH 6.4, slope of 27.7±0.8mVdecade(-1), linear concentration range of 1×10(-7) to 1.0×10(-1)M Cd(2+) and limit of detection (S/N=3) of 2.51×10(-8)M were obtained. The ISE was very selective towards Cd(2+), with K(pot)<1×10(-2) in the presence of the usual cations and anions in water samples. Response time and shelf life of less than 1min and 90 days, respectively, were observed. Its application was tested in various types of samples.

Matched MeSH terms: Ion-Selective Electrodes
Enhancement of fluoride release from glass ionomer cement following a coating of silver fluoride

Ariffin Z, Ngo H, McIntyre J

Aust Dent J, 2006 Dec;51(4):328-32.
PMID: 17256308

BACKGROUND: This study investigated the extent to which a coating of 10% silver fluoride (AgF) on discs of glass jonomer cements (GIGs) would enhance the release of fluoride ion into eluting solutions at varying pH.
MATERIALS AND METHODS: Forty discs each of Fuji LX, Fuji VII and of Vitrebond were prepared in a plastic mould. Twenty discs of each material were coated for 30 seconds with a 10% solution of AgF. Five discs each of coated and uncoated material were placed individually in 4m1 of differing eluant solutions. The eluant solutions comprised deionized distilled water (DDW) and three separate acetate buffered solutions at pH 7, pH 5 and pH 3. After 30 minutes the discs were removed and placed in five vials containing 4m1 of the various solutions for a further 30 minutes. This was repeated for further intervals of time up to 216 hours, and all eluant solutions were stored. Fluoride concentrations in the eluant solutions were estimated using a fluoride specific electrode, with TISAB IV as a metal ion complexing and ionic concentration adjustment agent. Cumulative fluoride release patterns were determined from the incremental data.
RESULTS: The coating of AgF greatly enhanced the level of fluoride ion release from all materials tested. Of the uncoated samples, Vitrehond released the greater concentrations of fluoride ion, followed by Fuji VII. However, cumulative levels of fluoride released from coated samples of the GICs almost matched those from coated Vitrebond.
CONCLUSIONS: It was concluded that a coating of 10% AgF on GICs and a resin modified GIC greatly enhanced the concentration of fluoride released from these materials. This finding might be applied to improving protection against recurrent caries, particularly in high caries risk patients, and in the atraumatic restorative technique (ART) of restoration placement.

Matched MeSH terms: Ion-Selective Electrodes