Determination Of Iodide Research Articles

"Novel Spectrophotometric Determination of Isopropamide Iodide in Pharmaceutical Formulations and Environmental Wastewater Samples: Application to Content Uniformity Testing"

"Novel Spectrophotometric Determination of Isopropamide Iodide in Pharmaceutical Formulations and Environmental Wastewater Samples: Application to Content Uniformity Testing"

Study of the degradation behavior of enisamium iodide, tilorone dihydrochloride, morpholinium thiazotate in the soil by the GC-Fid method

The aim. To study the behaviour of enisamium iodide, thiloron dihydrochloride, morpholinium thiazotate, and the suitability of the previously developed GC-FID methodology in soil. Materials and methods. The determination of the Enisamium iodide, Tilorone dihydrochloride, and Morpholinium thiazotate in soil gas chromatography with a flame ionization detector using the Rxi-5 ms (30 m long, 0.25 mm outer diameter and 0.25 μm liquid stationary phase thickness). Results. A study was conducted on the behaviour of enisamium iodide, thiloron dihydrochloride, and morpholinium thiazotate in soil, along with the assessment of the suitability of the developed GC-FID methodology for determination in soil. The half-life in soil was investigated, which amounted to 45 days for enisamium iodide, 30 days for thilorone dihydrochloride, and 7 days for morpholinium thiazotate, with corresponding decay rate constants of 0.001 mg/mL, 0.001 mg/mL, and 0.0005 mg/mL, respectively. Conclusions. The previously developed GC-FID methodology is suitable for the determination of enisamium iodide, thilorone dihydrochloride, and morpholinium thiazotate in soil, with necessary analysis conditions established. Under aerobic conditions, the selected pharmaceutical preparations' dispersion rate followed the following decreasing order: enisamium iodide > thilorone dihydrochloride > morpholinium thiazotate in soil

Gold leaf electrochemical flow cell for determination of iodide in nuclear emergency tablets

This work introduces an innovative gold-leaf flow cell for electrochemical detection in flow injection (FI) analysis. The flow cell incorporates a hammered custom gold leaf electrochemical sensor. Hammered gold leaves consist of pure gold and are readily available in Thailand at affordable prices (approximately $0.085 for a sheet measuring 40 mm × 40 mm). Four sensing devices can be made from a single sheet of this gold leaf, resulting in a production cost of approximately $0.19 per sensor. Each electrochemical sensor has the gold leaf as the working electrode, together with a printed carbon strip, and a printed silver/silver chloride strip as the counter and reference electrodes, respectively. Initial investigations using cyclic voltammetry of a standard 1000 μmol L⁻1 iodide solution in 60 mmol L⁻1 phosphate buffer (PB) solution at pH 5, demonstrated performance comparable to that of a commercial screen-printed gold electrode. The hammered gold leaf electrode was then installed in a commercial flow cell as part of an FI system. A sample or standard iodide solution (100 μL) is injected into the first carrier stream of phosphate buffer (PB) solution, which then merges to mix with the second stream of the same buffer solution before flowing into the flow cell for amperometric detection of iodide. The optimized operating conditions include a fixed potential of +0.39 V (vs Ag/AgCl), and a total flow rate of 3 mL min⁻1. A linear calibration is obtained in the concentration range of 1 to 1000 μmol L⁻1 I− with a typical equation of μA = (0.00299 ± 0.00004) × (μmol L−1 I−) + (0.021 ± 0.020), and R2 = 0.9994. Analysis of iodide using this gold leaf-FI system is rapid with sample throughput of 86 samples h⁻1 and %RSD of a sample of 100 μmol L⁻1 I⁻ of 1.2 (n = 29). The limit of detection, (calculated as 2.78 × SD of regression line/slope), is 27 μmol L⁻1 I−. This method was successfully applied to determine iodide in nuclear emergency tablets.

Sensitive determination of iodide at graphitic carbon nitride-chitosan composite modified screen-printed electrode in urine and salt using cathodic stripping voltammetry

Iodide is an important constituent in various biological processes; hence its determination is important. A simple voltammetric method has been investigated for iodide determination using disposable screen-printed electrode modified with graphitic carbon nitride-chitosan composite (gCN-Chit/SPE). The sensor presented excellent electrocatalytic response towards iodide sensing. The SEM analysis of the modified electrode showed a rough and sheet like morphology. The EDX analysis showed the high content of nitrogen elements in the composite layer of the modified electrode which is crucial for iodide ion sensing. Various parameters such as electrolyte concentration, deposition potential, deposition time etc. were optimized for iodide sensing. The use of low concentration of electrolyte favored the electro-oxidation of iodide. Under the suitable experimental conditions, the gCN-Chit/SPE exhibited good linear performance for iodide in the concentration range from 0.075 to 200 µM with a regression coefficient (R2) of 0.9946 and the limit of detection (LOD) of 0.01 µM. The electrode presented interference free effect for iodide in the presence of relatively high concentration of other substances. The sensor was applied to determine iodide in real samples such as urine, tap water and table salt. In real sample analysis good recoveries in percent was achieved using the developed electrode. Further, the composite layer at the electrode surface provided good mechanical stability and thus could be reused for several determinations. The results confirmed that the design electrochemical sensor could be successfully employed for real sample applications with highly sensitive iodide determination.

Hydrophobic barrier-free laminated paper-based analytical device (LPAD) using a diameter-based measurement for determination of iodide in pharmaceutical products

This work presents, for the first time, an exploitation of an argentometric Mohr's method for iodide detection using diameter-based measurement on laminated paper-based analytical device (LPAD). Our LPAD is simplified fabricated with no required hydrophobic barrier for patterning a detection flow channel. In the absence of a flow channel, the liquid is imbibed radially into the filter paper outward from the small center inlet hole. This imbibition leads to the measurement of diameter after the formation of the precipitation product. For LPAD, a rectangular piece of Whatman filter paper is cut and positioned between a top laminating sheet, which has a hole punched for inlet, and a bottom laminating sheet. The central inlet hole enables access to the liquid on the paper. For iodide analysis, silver nitrate is dispensed first, followed by the iodide standard/sample. This process leads to the formation of pale-yellow silver iodide solids on the paper. The chromate indicator solution is subsequently loaded to the paper. The color of the chromate solution imparts a tint to the circular band of silver iodide solids, resulting in an intense yellow color. When the silver iodide precipitates are stained, the chromate solution typically serves as an indicator, chemically reacting to an excess silver nitrate solution moistened on paper. This reaction generates an outer reddish-brown ring of silver chromate. The distinct color contrast between the intense yellow (tinted silver iodide) and reddish-brown (silver chromate) allows for clear observation of the measurement boundary, facilitating diameter-based measurements of the circular band of silver iodide. We demonstrate the applicability in analysis of pharmaceutical KI tablets. The quantitative results obtained from diameter-based measurement LPAD show good agreement with those obtained from the potentiometric method. Our hydrophobic barrier-free LPAD is rapid, cost-effective, low liquid consumption and applicable for onsite analysis.

Greening of the method for simultaneous determining the enisamium iodide and tilorone dihydrochloride using GC-FID assay

Pharmaceutical companies in Ukraine aspire to develop their innovative medicinal products and successfully introduce them to the global market. However, along with the prospects of increased usage of these pharmaceuticals, there arises a challenge of heightened waste production, making them a part of the over twenty million tons of PPCPs produced annually. Consequently, one of the tasks in producing new pharmaceuticals is the development of methodologies and approaches not only for quality control but also for their determination in the environment matrices.
 The aim. Develop and validate GC-FID chromatographic method for the simultaneous determination of Enisamium iodide and Tilorone dihydrochloride, evaluate their applicability, and compare their "greenness" with the previously developed HPLC method.
 Materials and methods. The determination of the Tilorone dihydrochloride and Enisamium iodide was carried out by gas chromatography with a flame ionization detector using the Rxi-5 ms (30 m long, 0.25 mm outer diameter and 0.25 μm liquid stationary phase thickness)
 Results. Chromatographic GC-FID methods have been developed for the simultaneous determination of Enisamium iodide and Tilorone dihydrochloride. Optimal sample preparation conditions were established, and a validation process was conducted. A comparison with the previously developed HPLC method was made regarding "greenness."
 Conclusions. The developed GC-FID methodology is accurate and more environmentally friendly compared to the previously established methods. It can be recommended to determine Enisamium iodide and Tilorone dihydrochloride in the environmental matrices. It is considered environmentally friendly based on the overall GREENness (AGREE) scale, scoring 0.73 (>0.70), which demonstrates the environmentally favourable nature of the proposed analytical approach

Determination of primary and secondary oxidation products in vegetable oils with gold nanoparticle based fluorometric turn-on nanosensor: A new total oxidation value

Oxidation of fats and oils gives rise to lipid hydroperoxides as primary oxidation products (POPs) and carbonyl compounds as secondary oxidation products (SOPs). Here, we report the sensitive detection of POPs and SOPs (oxidation products) involving direct and indirect redox reactions with iodide ions, respectively, using the fluorophore probe (fluorescein-5-isothiocyanate-gold nanoparticles; FITC-AuNPs). Iodide released the fluorescent FITC from FITC-AuNPs in the turn-on mode. In case of SOPs, an indirect iodide determination was made through the use of chloramine-T as carbonyl reagent. To various vegetable oil samples, deep frying process (at 160 °C, simulating frying conditions) and soft oil oxidation (at 100 °C, simulating cooking conditions) were carried out for a period of time (1, 5 and 10 days). Total content of POPs varied between 4.00 and 5.70 g TBHP (t-butylhydroperoxide)/kg oil, and the amount of SOPs was found as 1.12–4.11 g t-2-nonenal/kg oil in non-oxidized oil samples. The proposed method was validated against FOX and p-anisidine value (p-AV) assays. Sensory analyses (taste, color, smell and appearance) results of non-oxidized and deep-fried oil samples were consistent with those of the proposed FITC-AuNP nanosensor. Finally, a new total oxidation (TOD) value (expressed as iodide equivalent meq/kg oil) was proposed to determine the overall oxidation state and quality of the oils. Our proposed TOD value is not only mathematically precise with respect to its units (i.e. POPs and SOPs are added up in the same equivalent units to obtain TOD) but also is in better accordance with the results of sensory analysis.

Simultaneous determination of flouride, iodate and iodide by ion chromatography in caustic off-gas scrubber of nuclear recycle facilities by employing dual detectors

ABSTRACT An ion chromatography method was developed for the simultaneous determination of fluoride, iodate and iodide in a caustic scrubber solution used for trapping off-gases released during the dissolution of nuclear fuels. A separation between iodate and fluoride could be realized with 0.6 mM hydroxide, which is too weak to elute other anions including iodide in reasonable time. Studies were carried out at different column temperature, and with the help of Van’t Hoff plots the thermodynamic parameters associated with the column equilibrium were estimated, which helped in understanding the co-elution of iodate and fluoride at higher concentration of eluent. An arrangement of conductivity detector and UV-VIS detector in sequence after the ion exchange column (with 15 mM NaOH as eluent) was used for recording chromatograms for conductivity signal and UV-VIS signal simultaneously. The information from the two chromatograms was utilized to quantify iodate, fluoride and iodide in a single run. The limit of detection for fluoride, iodate and iodide is 7 ppb, 10 ppb and 12 ppb, respectively. The precision of the method is better than 2% (RSD) at 0.5 mg/L. The method was used successfully for the real sample analysis.

Validation of a Novel RP-HPLC Technique for Simultaneous Estimation of Lignocaine Hydrochloride and Tibezonium Iodide: Greenness Estimation Using AGREE Penalties.

Herein, we reported an HPLC method for the simultaneous determination of tibezonium iodide (TBN) and lignocaine hydrochloride (LGN). The method was developed according to the International Conference for Harmonization guidelines (ICH) Q2R1 using Agilent® 1260 with a mobile phase consisting of acetonitrile and phosphate buffer (pH 4.5) in a volumetric ratio of 70:30 and flowing through a C8 Agilent® column at 1 mL/min. The results revealed that TBN and LGN peaks were isolated at 4.20 and 2.33 min, respectively, with a resolution of 2.59. The accuracy of TBN and LGN was calculated to be 100.01 ± 1.72% and 99.05 ± 0.65% at 100% concentration, respectively. Similarly, the respective precision was 100.03 ± 1.61% and 99.05 ± 0.48%. The repeatability for TBN and LGN was found to be 99.05 ± 0.48% and 99.19 ± 1.72%, respectively, indicating that the method was precise. The respective regression co-efficient (r2) for TBN and LGN was found to be 0.9995 and 0.9992. Moreover, the LOD and LOQ values for TBN were 0.012 and 0.037 µg/mL, respectively, while for LGN, they were 0.115 and 0.384 µg/mL, respectively. The calculated greenness of the method for ecological safety was found to be 0.83, depicting a green contour on the AGREE scale. No interfering peaks were found when the analyte was estimated in dosage form and in volunteers' saliva, depicting the specificity of the method. Conclusively, a robust, fast, accurate, precise and specific method was successfully validated to estimate TBN and LGN.

Ion-pair extractive spectrophotometric determination of isopropamide iodide in pharmaceutical formulations and environmental wastewater samples using Bromo phenol blue

A simple, accurate and sensitive spectrophotometric method was developed for the determination of isopropamide iodide in pharmaceutical formulations and environmental wastewater samples. The method was based on the formation of ion-pair between isopropamide iodide and bromophenol blue (BPB). The colored product was extracted into chloroform and measured spectrophotometrically at 600 nm. Beer’s law was obeyed in the concentration range of 2.0-20.0 μg/mL with molar absorptivity and Sandell’s sensitivity of 3.17 × 104 L /mol. cm and 15.15 ng/.cm2 respectively. The relative standard deviation (RSD) is better than 1.5. The method was applied successfully to the determination of isopropamide iodide in environmental wastewater samples and in pharmaceutical formulations (tablets).

Определение содержания йода, йодидов и йодатов в пищевых продуктах

Currently iodine deficiency diseases are one of the most important medical and social problems. In this regard, the purpose of the study is to determine the content of iodine, iodides, iodates in iodized salt, drinking and mineral water, seaweed, to determine the stability of the iodine content in salt. For the qualitative determination of iodides and iodates ions in salts and molecular iodine in seaweed, an iodine starch reaction has been carried out. The presence of iodide ions in iodized water has been determined by reaction with silver nitrate and chlorine water, the iodine released has been extracted with chloroform. Quantitative determination of iodine in salt has been carried out by the titrimetric method, in water – by colorimetric method, in seaweed – by gravimetric method with subsequent titration. The study has found that iodized salt contains iodine in the form of potassium iodate, in an amount of 18.65 μg / g of elemental iodine, kelp contains molecular iodine in the amount of 8.12 μg / g of elemental iodine, and iodized water contains potassium iodide in the amount of 0.327 μg / ml of elemental iodine. The study has proved that over time, the amount of iodine in the salt iodized with potassium iodate decreases after a month by 5.6 times. In order to comply with the daily rate of iodine intake, it is necessary to include in your diet about 9.7 g of iodized salt, which exceeds the daily norm of its consumption in 5 g. In this regard, it is recommended to use iodized salt (not more than 5 g) or iodized water (0.7 L of water) or kelp (18.47 g) as a prevention of iodine deficiency.

A 3D microfluidic paper-based analytical device with smartphone-assisted colorimetric detection for iodine speciation in seaweed samples

The present work reports on the development of a 3D origami microfluidic paper-based analytical device (3D µPAD) for the determination of iodide and iodate in edible seaweeds by smartphone-based colorimetric detection. In addition, a methacrylate holder was designed and fabricated to enhance interlayer contact in 3D µPADs, obtaining excellent sensitivity and precision, also allowing real-time monitoring in a straightforward and expeditious way. The reported assay, based on the formation of a blue colored triiodide-starch complex at the detection areas of the 3D µPAD, represents an affordable, fast and greener alternative for the simultaneous determination of inorganic iodine species. Under optimal conditions, the proposed method showed limits of detection and quantification of 9.8 and 32.7 µM for I- and 0.6 and 1.8 µM for IO3-, respectively. The repeatability, expressed as relative standard deviation, was 1.7% and 3.3% for I- and IO3-, respectively. The proposed 3D µPAD was applied to the determination of iodine species in extracts of edible seaweeds and related food additives, showing satisfactory recoveries (90–109%).

Electrocatalytic response of chitosan modified multiwall carbon nanotube paste electrode toward iodide: A facile voltammetric method for determination of iodide in biological sample

Herein we report, a simple operable, sensitive, and highly selective, voltammetric method for the determination of iodide (Iˉ) using chitosan modified multiwall carbon nanotube paste electrode (chit-MWCNTPE). It is established that chit-MWCNTPE exhibited a pronounced response toward Iˉ oxidation. The peak potential of Iˉ is recorded at 0.69 V vs SCE. The conditions such as scan rate (V.s−1), accumulation time (ta), and pH are thoroughly optimized for the voltammetric determination of Iˉ. A wide range linear response is observed between oxidation peak current and Iˉ concentration (0.1–100 μM). The limit of detection (LOD) for Iˉ on chit-MWCNTPE is found to be 0.03 μM. The developed method is highly selective for Iˉ detection in the presence of various interfering ions. The method is successfully applied for the determination of Iˉ in urine samples. The method has high selectivity for Iˉ detection at comparably low potential as well as amiable LOD and Linear range.

The use of nanocomposite approach in the construction of carbon paste electrode and its application for the potentiometric determination of iodide

The use of nanocomposite approach in the construction of carbon paste electrode and its application for the potentiometric determination of iodide

Enhanced electrochemical detection of iodide at a reduced graphene oxide–modified carbon electrode in iodized salts

In this study, enhancement of electrochemical performance of electrochemically reduced graphene oxide (ERGO) on a screen-printed carbon electrode (SPCE) (ERGO/SPCE) coupled with ion-pairing (cetyltrimethylammonium bromide, CTAB) for the determination of iodide in table salt has been described. The electrode modification of ERGO/SPCE was conducted using cyclic voltammetric (CV) scanning in the potential range of 1.3–0.4 V for 50 cycles after the drop-casting of graphene oxide (GO) suspension on the SPCE. It was found that the electro-active surface area of ERGO/SPCE was increased by 1.5-fold compared to the bare SPCE. ERGO/SPCE sensor displays linearity towards iodide in the concentration range from 0.020 to 1.0 mg/L (sensitivity = 5.40 µA(mg/L)−1, R2 = 0.9906) with the limit of detection (LOD) and limit of quantitation (LOQ) of 0.070 mg/L and 0.21 mg/L, respectively. The comparison between polarography and ERGO/SPCE sensor was in good agreement.

Tentative Application of a Streamlined Protocol to Determine Organ-Specific Regulations of Deiodinase 1 and Dehalogenase Activities as Readouts of the Hypothalamus-Pituitary-Thyroid-Periphery-Axis.

In animal studies, both in basic science and in toxicological assessment of potential endocrine disruptors, the state of the thyroid hormone (TH) axis is often described and defined exclusively by the concentrations of circulating THs and TSH. Although it is known that the local, organ-specific effects of THs are also substantially regulated by local mechanisms such as TH transmembrane transport and metabolism of TH by deiodinases, such endpoint parameters of the axis are rarely assessed in these experiments. Currently developed in vitro assays utilize the Sandell-Kolthoff reaction, a photometric method of iodide determination, to test the effect of chemicals on iodotyrosine and iodothyronine deiodinases. Furthermore, this technology offers the possibility to determine the iodine content of various sample types (e.g., urine, ex vivo tissue) in a simple way. Here, we measured deiodinase type 1 and iodotyrosine dehalogenase activity by means of the Sandell-Kolthoff reaction in ex vivo samples of hypo- and hyperthyroid mice of two age groups (young; 3 months and old; 20 months). In thyroid, liver and kidney, organ-specific regulation patterns emerged across both age groups, which, based on this pilot study, may serve as a starting point for a deeper characterization of the TH system in relevant studies in the future and support the development of Integrated Approach for Testing and Assessment (IATA).

Two different spectrophotometric methods for simultaneous determination of binary mixture of atenolol and amlodipine in commercial formulation

Two different spectrophotometric methods for simultaneous determination of binary mixture of atenolol and amlodipine in commercial formulation

Solid-contact potentiometric sensors based on silver nanoparticles in the supramolecular matrix for the determination of halogenide ions

Determination of halogenide ions in pharmaceuticals and various waters is an actual task for the modern analytical chemistry. In the current work, solid-contact potentiometric sensor, based on the glassy carbon electrode covered with the layer of electropolymerized polyaniline and suspension of silver nanoparticles in the matrix of thiacalix[4]arene derivative bearing terminal catechol groups, has been described. The suspension was obtained by the chemical reduction of silver ions with the thiacalix[4]arene and drop casted on the polyaniline layer. The sensor showed potentiometric response to chloride-, bromide and iodide ions. For the simultaneous determination of iodide and bromide ions, a multi-sensor system, consisting of four electrodes with the different volumes of the suspension placed on the polyaniline layer, has been developed. The possibility of the response prediction within the simple additive model was found for the set of the iodide and bromide mixtures. In a similar manner, simultaneous determination of both ions in the variable mixtures has been performed. The multi-sensor system was tested during the determination of iodides in iodine containing pharmaceuticals and the determination of iodide and bromide ions in the artificial mineral water samples. Ionic chromatography was chosen as the comparison method. Sensors made it possible to determine from 0.1 μM to10 mMiodide and bromide ions in mixtures. The proposed approach and solid-contact potentiometric sensors can be used in the analysis of ion content of the waters and in control of the production and storage conditions of pharmaceuticals.

Simultaneous Determination of Iodide and Iodate in Salts Using Capillary Zone Electrophoresis with Transient Isotachophoresis

Simultaneous Determination of Iodide and Iodate in Salts Using Capillary Zone Electrophoresis with Transient Isotachophoresis

Determination of purity and anionic exchange efficiency of amino acid ionic liquids synthesis by multiple-injection capillary zone electrophoresis

The purity of ionic liquids (IL) is important for its performance, so the methods able to quantify low concentration impurities are necessaries. Therefore, this paper aims to determine the purity and the anionic exchange efficiency for the preparation of amino acids ionic liquids (AAIL). For this, a Multiple-Injection Capillary Zone Electrophoresis (MICZE) method with direct UV detection was developed and optimized for iodide (I−) determination as impurity of AAIL synthesis, comparing this method with traditional injection modes. Furthermore, this paper aims to demonstrate the use of factorial design methods for the optimization of MICZE method. The method optimization allowed five consecutives I− injections of sample in a single run, with analysis time of less than 3 min, showing a larger analytical frequency, counting with 31 injections per hour. It was possible to determine the high purity of the prepared and analyzed AAIL, ranging from 89% to 95% and its overall ionic exchange yield varying from 55% to 87%.