An investigation of solubility of aliquat 336 in different extracted solutions

A major concern in solvent extraction processes is the loss of extractant into the aqueous phase due to its slight solubility in the aqueous phase. Similarly, in membrane extraction processes, extractant loss through extractant leakage from the membrane into the aqueous phase is also a concern. Several published membrane extraction studies using Aliquat 336 as the extractant, have expressed this concern, but none has studied extractant leakage quantitatively. It is the authors’ opinion that the extractant leakage should be considered as a technical parameter of a membrane. In our laboratory active progress has been made in using Aliquat 336 ‘entangled’ into the polymer membranes to remove heavy metal ions from wastewater samples. In this work, we studied the loss of Aliquat 336 from the point of view of its solubility in aqueous solutions. The results showed that the solubilities of Aliquat 336 in an aqueous phase acidified with 2 M HCl is about 0.1 g/100 m/ of the solution. This figure provides a useful guideline for evaluating the leakage of the Aliquat 336 extractant from the membranes

Improved membranes for the extraction of heavy metals

This work presents a series of experimental tests on new practical approaches in membrane design to improve extraction capacity and rate. We chose an extraction system involving Aliquat 336 as the extractant and Cd(II) as the metal ion to be extracted to demonstrate these new approaches. The core element in the new membrane assembly was the extractant loaded sintered glass filter. This membrane assembly provided a large interface area between the extractant and the aqueous solution containing metal ions. By recycling the aqueous solution through the membrane assembly, the extraction rate was significantly improved. The membrane assembly also offered good extraction capacity

Experimental evidence to support the patent application for an invention of an apparatus for reducing oxidation of metal vehicle components

To investigate the validity of the claim thaat by applying a positive ptential to all of the metal components of motor vehicles, when they are turned off, can aid in the reduction of the oxidation process of the metals

A novel polymer membrane for extraction applications

In this study, a new type of Aliquat 336/PVC membrane has been made for extraction experiments. This new membrane is capable of holding more Aliquat 336 than previously developed extraction membranes, hence overcoming a major problem that has confronted many researchers for a long time. The new membrane has been used to investigate the rate of extraction for the Cd(II) ion in 2.0 M HCl solution and the effect of membrane thickness on the rate of extraction. The experimental results have shown this new membrane has a promising future in relevant industrial applications. A new method is also used in this study to qualitatively identify the oily substance on the surface of membrane after the extraction experiment was completed. This oily substance has been found to be Aliquat 336. <br /

Modes of handling Oxygen Radical Absorbance Capacity (ORAC) data and reporting values in product labelling

Antioxidant measurement assays are widely used and should be chosen based on their being fit for purpose. Likewise, the mode of reporting antioxidant measurements should also be fit for purpose. The Oxygen Radical Absorbance Capacity (ORAC) assay is widely used internationally for measuring the antioxidant capacity of commodities using the peroxyl radical. However, the current mode of reporting of the ORAC values is not obvious, especially for the consumer groups. In this mode, reporting of the ORAC values is the unit of micromoles of vitamin E analogue (VEA), known commercially as Trolox Equivalents per kilogram or per litre (μM T.E./kg or L). Unlike mass units, molar units are not widely used in nutrition information panels (NIP). This paper presents a simple mathematical model for conversion of ORAC values to mass units to facilitate better understanding of the antioxidant capacity quoted. Additionally, mass values are in keeping with current labelling practice in Australia. Unless legislation is passed for the regulation of ORAC data use in labelling and product marketing, mass units should be considered as a mode of reporting, limiting sensationalism of antioxidant capacity and keeping with current labelling practice

Separation of cobalt(II) from nickel(II) by solid-phase extraction into Aliquat 336 chloride immobilized in poly(vinyl chloride)

A solid-phase absorbent obtained by the immobilization of Aliquat 336 chloride in poly(vinyl chloride) is reported to extract preferentially Co(II) from its 7 M hydrochloric acid solutions containing Ni(II). Under the experimental conditions there was no extraction of Ni(II) which allowed the complete separation of these two ions. Co(II) was rapidly and quantitatively back-extracted with deionised water. A mechanism for the extraction of Co(II) is proposed based on the formation of the ion-pair A+[HCoCl4]− where A+ is the Aliquat 336 cation. Fe(III) and Cd(II), usually present in Co(II) and Ni(II) samples, were also extracted into the solid-phase absorbent though at a slower rate than Co(II) and they did not interfere with the separation of Co(II) from Ni(II). It was also demonstrated that this approach allowed the complete separation of Ni(II) from the other metal ions mentioned above

Study protocol on risk factors for the diagnosis of gestational diabetes mellitus in different trimesters and their relation to maternal and neonatal outcomes (GDM-RIDMAN)

INTRODUCTION: Gestational diabetes mellitus (GDM) is often associated with adverse pregnancy outcomes. However, the association of risk factors with GDM diagnosis, maternal and neonatal health outcomes is less established when compared with women without GDM. We aim to examine the diagnostic accuracy of the conventional and novel risk factors for a GDM diagnosis and their impact on maternal and neonatal health outcomes. METHODS AND ANALYSIS: This retrospective cohort and nested case–control study at six public health clinics is based on medical records and questionnaire survey of women between 2 and 12 months postpartum. The estimated required sample size is 876 complete records (292 cases, 584 control, at a ratio of 1:2). Oral glucose tolerance test results will be used to identify glucose dysregulation, and maternal and neonatal outcomes include maternal weight gain, pre-eclampsia, polyhydramnios, mode of delivery, preterm or postdate birth, complications in labour, birth weight, gestational age at birth, Apgar score, congenital anomaly, congenital hypothyroidism, neonatal death or stillbirth, hypoglycaemia and hyperbilirubinaemia. Psychosocial measures include the WHO Quality of Life: brief, mother–infant bonding (14-item Postpartum Bonding Questionnaire and 19-item Maternal Postnatal Attachment Scale), anxiety (7-item Generalised Anxiety Disorder), depression (9-item Patient Health Questionnaire) and stress (Perceived Stress Scale symptoms) questionnaires. The comparative incidences of maternal and neonatal health outcomes, the comparative prevalence of the psychosocial outcomes between women with GDM and without GDM, specificity, sensitivity, positive and negative predictive values of the risk factors, separately and combined, will be reported. All GDM risk factors and outcomes will be modelled using multivariable regression analysis and the receiver operating characteristics curve will be reported. ETHICS AND DISSEMINATION: This study was approved by the Malaysia Research and Ethics Committee, Ministry of Health Malaysia. Informed consent will be obtained from all participants. Findings will be submitted for publications in scientific journals