Spectrophotometric and Fluorometric Methods for the Determination of Fe(III) Ions in Water and Pharmaceutical Samples

Abstract

Chemical sensors based on mesoporous silica nanotubes (MSNTs) for the quick detection of Fe(III) ions have been developed. The nanotubes’ surface was chemically modified with phenolic groups by reaction of the silanol from the silica nanotubes surface with 3-aminopropyltriethoxysilane followed by reaction with 3-formylsalicylic acid (3-fsa) or 5-formylsalicylic acid (5-fsa) to produce the novel nanosensors. The color of the resultant 3-fsa-MSNT and 5-fsa-MSNT sensors changes once meeting a very low concentration of Fe(III) ions. Color changes can be seen by the naked eye and tracked with a smartphone or fluorometric or spectrophotometric techniques. Many experimental studies have been conducted to find out the optimum conditions for colorimetric and fluorometric determining of the Fe(III) ions by the two novel sensors. The response time, for the two sensors, that is necessary to achieve a steady spectroscopic signal was less than 15 s. The suggested methods were validated in terms of the lowest limit of detection (LOD), the lowest limit of quantification (LOQ), linearity, and precision according to International Conference on Harmonization (ICH) guidelines. The lowest limit of detection that was obtained from the spectrophotometric technique was 18 ppb for Fe(III) ions. In addition, the results showed that the two sensors can be used eight times after recycling using 0.1 M EDTA as eluent with high efficiency (90%). As a result, the two sensors were successfully used to determine Fe(III) in a variety of real samples (tap water, river water, seawater, and pharmaceutical samples) with great sensitivity and selectivity.

A direct one-step synthesis of a smart graphene/silica nanocomposite and its application for improving the acid resistance and corrosion resistance properties of waterborne epoxy coatings

“…In order to evaluate the self-healing quantitatively, the concentration of ferric ions ([Fe 3+ ]) in the soaking bath solution of different coating systems was measured by UV/vis spectroscopy via a conventional sulfosalicylic acid spectrophotometry method. 32 The standard curve is shown in Fig. S6, † and the absorbance after different soaking times is shown in Table S3.…”

Enhanced Adsorption and Evaluation of Tetracycline Removal in an Aquatic System by Modified Silica Nanotubes

“…The MSNTs and its 3-APTES@MSNT nanoadsorbent have been synthesized previously in our previous work. 43 The synthesis process is illustrated in detail in the Supplementary Material .…”

Fluorescence determination of Fe(iii) in drinking water using a new fluorescence chemosensor

“…Numerous techniques for determining Fe(III) have been published such as colorimetric analysis, 10 atomic absorption spectroscopy, 11,12 electrochemical, [13][14][15] mass spectrometry 16 and uorescence spectroscopic analysis. [17][18][19][20][21][22][23][24] The uorimetric assay is a popular approach because of its simplicity of use, fast time of response with simple requirements of instrumentation, high efficiency and sensitivity. Therefore, there has been an increase in interest in the development of uorescent probes for the detection of Fe(III).…”