scholarly journals Solid-Phase Extraction and Spectrophotometric Determination of Iodate in Table Salt after Azo Dye Formation

1999 ◽  
Vol 82 (1) ◽  
pp. 167-171 ◽  
Author(s):  
Shefali Gosain ◽  
Madhurima Pandey ◽  
Krishna K Verma
Keyword(s):  
Solid Phase Extraction ◽  
Azo Dye ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Phase Extraction ◽  
Table Salt ◽  
Acid Cation

Abstract A new reaction for determining iodate in table salt is proposed. It is based on oxidation of phenylhy-drazine-4-sulfonic acid by iodate in acidic medium to the 4-diazobenzenesulfonic acid cation and its electrophilic coupling with N-(1-naphthyl)ethylene- diamine dihydrochloride to give an azo dye, which is measured spectrophotometrically at 545 nm. Maximum molar absorptivity was 8.41 ×104 L/mol cm. A rectilinear calibration graph was obtained for iodate in the range 0.25–5 mg/L. The azo dye could be preconcentrated at least 40-fold by solid-phase extraction on C18 sorbent. The limit of detection was 0.6 μg iodate/L. The method was used to determine iodate in laboratory-prepared and commercially available table salt samples. Up to 5 mg bromate/kg and 10 mg iron(lll)/kg in table salt did not interfere.

scholarly journals Spectrophotometric Determination of Iron(II) after Solid Phase Extraction of Its 2,2′ Bipyridine Complex on Silica Gel-Polyethylene Glycol

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Nahid Pourreza ◽  
Saadat Rastegarzadeh ◽  
Ali Reza Kiasat ◽  
Hossein Yahyavi
Keyword(s):  
Polyethylene Glycol ◽  
Solid Phase Extraction ◽  
Silica Gel ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Calibration Graph ◽  
Phase Extraction ◽  
Relative Standard

A new solid phase extraction procedure was developed for preconcentration of iron(II) using silica gel-polyethylene glycol (silica-PEG) as an adsorbent. The method is based on retention of iron(II) as 2,2′ bipyridine complex on silica-PEG. The retained complex is eluted by 1.0 mol L−1of sulfuric acid-acetone mixture (1:2) and its absorbance is measured at 518 nm, spectrophotometrically. The effects of different parameters such as pH, concentration of the reagent, eluting reagent, sample volume, amount of adsorbent, and interfering ions were investigated. The calibration graph was linear in the range of 1–60 ng mL−1of iron(II). The limit of detection based on3Sbwas 0.57 ng mL−1and relative standard deviations (R.S.D) for ten replicate measurements of 12 and 42 ng mL−1of iron(II) were 2.4 and 1.7%, respectively. The method was applied to the determination of of iron(II) in water, multivitamin tablet, and spinach samples.

Development of a solid-phase extraction – spectrofluorimetric method for trace glutathione determination

2011 ◽  
Vol 89 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Ke-Jing Huang ◽  
Cong-Hui Han ◽  
Ying-Ying Wu ◽  
Chao-Qun Han ◽  
De-Jun Niu ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Calibration Graph ◽  
Extraction Column ◽  
Phase Extraction ◽  
Selective Reaction ◽  
Spectrofluorimetric Method ◽  
Relative Standard

A simple and efficient solid-phase extraction – spectrofluorimetric method has been developed to determine glutathione (GSH). Fluorescent probe N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-yl)methyl)iodoacetamide (BODIPY Fl-C1-IA) was used as the derivatization reagent. The procedure was based on a BODIPY Fl-C1-IA selective reaction with GSH to form the highly fluorescent product BODIPY Fl-C1-IA–GSH, using a solid-phase extraction column and spectrofluorimetric determination. The variables affecting analytical performance were studied and optimized. The calibration graph using the preconcentration system for GSH was linear over the range of 1–200 nmol/L with a limit of detection of 0.05 nmol/L (signal-to-noise ratio = 3). The relative standard deviation for six replicate determinations of GSH at the 100 nmol/L concentration level was 3.9%. The method was applied to water samples and average recoveries between 87.5% and 111.5% were obtained for spiked samples.

scholarly journals Determination of Phthalate Plasticisers in Palm Oil Using Online Solid Phase Extraction-Liquid Chromatography (SPE-LC)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Nazarudin Ibrahim ◽  
Rozita Osman ◽  
Azmui Abdullah ◽  
Norashikin Saim
Keyword(s):  
Solid Phase Extraction ◽  
Palm Oil ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Array Detector ◽  
Phase Extraction ◽  
Extraction Solvent ◽  
Online Solid Phase Extraction

Contamination of phthalates plasticisers to food has raised concern as some of the phthalates are suspected to be endocrine disruptors. The phthalates have high affinity with oily environment and analysing these chemicals in such matrices is difficult because of the trace amount of the analyte and interference from matrix. An online solid phase extraction (SPE) technique using a large volume (3.5 mL) injection was developed for the analysis of 6 common plasticisers in palm oil. A simple sample preparation involving alumina as a fat retainer and methanol : acetonitrile (1 : 1) as the extraction solvent was performed prior to the usage of online SPE-LC system. This system consists of two columns, C16for the solid phase extraction (SPE) and C18as the analytical column, and a photo diode array detector. The calibration curves were linear from 5 to 1000 μg L−1, with correlation coefficients above 0.99. The instrumental limit of detection was 3 μg L−1and satisfactory recovery was obtained. A screening on a few samples in the retail market revealed the presence of dibutyl phthalate (DBP) and butylbenzylphthalate (BBP) in the palm oil, with concentration less than 1 mg L−1.

scholarly journals HPLC method validation and application for organic acid analysis in wine after solid-phase extraction

2016 ◽  
Vol 35 (2) ◽  
pp. 225 ◽  
Author(s):  
Violeta Ivanova-Petropulos ◽  
Krste Tašev ◽  
Marina Stefova
Keyword(s):  
Solid Phase Extraction ◽  
Organic Acids ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Hplc Method ◽  
Phase Extraction ◽  
Hplc Separation ◽  
Limit Of Quantification

<p>A solid-phase extraction method followed by reverse phase high-performance liquid chromatography (RP-HPLC) was optimized and validated for the quantitative determination of tartaric, malic, shikimic, lactic, citric and succinic acids in wine. Solid-phase extraction was carried out with C18 cartridges and extraction recoveries for all acids ranging from 98.3 to 103% were obtained. HPLC separation was performed with isocratic elution on a LiChrosorb RP-18 column (250 × 4.6 mm I.D., 5 µm) protected with the appropriate guard column. The mobile phase was a 5 mM solution of H<sub>3</sub>PO<sub>4</sub> with pH 2.1 at a flow rate of 1 ml/min. Detection of the organic acids was performed at 210 nm. The developed method was validated by checking its linearity, limit of detection (LOD), limit of quantification (LOQ), precision and recovery. The method was applied to the analysis of organic acids in Macedonian red and white wines.</p>

scholarly journals Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
José A. Rodríguez ◽  
Karen A. Escamilla-Lara ◽  
Alfredo Guevara-Lara ◽  
Jose M. Miranda ◽  
Ma. Elena Páez-Hernández
Keyword(s):  
Activated Carbon ◽  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Magnetic Solid Phase Extraction ◽  
Phase Extraction ◽  
Optimal Conditions ◽  
Magnetic Solid ◽  
Nonalcoholic Beverages

A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L−1, with a limit of detection of 1 mg L−1. The method was validated by comparing the results with those obtained by HPLC. A precision of<5.0% was obtained in all cases and no significant differences were observed(P<0.05).

scholarly journals Pipette Tip Solid-Phase Extraction Combined with Fluorescence Spectroscopy for Determination of Selenium in Green Tea Samples

2021 ◽  
Vol 913 (1) ◽  
pp. 012064
Author(s):  
S R Kamali ◽  
C H Tsai ◽  
C N Chen
Keyword(s):  
Solid Phase Extraction ◽  
Green Tea ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Standard Addition ◽  
Phase Extraction ◽  
Addition Method ◽  
The Matrix ◽  
Pipette Tip

Abstract In this study, the custom-built pipette-tip solid phase extraction (PT-SPE), was used for pre-concentrating the selenium (Se) in green tea samples. The PT-SPE was prepared using a pipette tip and C18 as the adsorbent that was placed between glass wool. This method afforded several advantages in terms of efficiency of extraction time (8 min), sample (2 mL), and solvent (1 mL) volumes with less wastage of solvent. Under optimal conditions of extraction, this method yielded good linearity (r2=0.998) for the Se calibration curve and good limit of detection (0.2 μg/L) and quantification (0.6 μg/L). The standard addition method was used to remove the matrix effect. The recovery percentages of tea samples spiked with different Se concentrations ranged from 97.7 to 106.0%, indicating that the proposed method would be suitable for the determination of Se in green tea samples.

scholarly journals Determination of Ranitidine in Human Plasma by SPE and ESI-LC-MS/MS for Use in Bioequivalence Studies

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Karini B. Bellorio ◽  
Maria Isabel R. Alves ◽  
Nelson R. Antoniosi Filho
Keyword(s):  
Solid Phase Extraction ◽  
Human Plasma ◽  
Extraction Method ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Internal Standard ◽  
Phase Extraction ◽  
Good Separation ◽  
Limit Of Quantification

A method for determining ranitidine in human plasma by ESI-LC-MS/MS was validated, using propranolol as internal standard. The extraction method used was solid phase extraction (SPE). Chromatographic separation was performed in a Chromolith C18 (50 mm × 4.6 mm i.d.) analytical column, which provided good separation of ranitidine and propranolol peaks with an analysis time of 2.5 minutes. Extraction yields of 94.4% for ranitidine and 89.4% for the internal standard were obtained. The lower limit of quantification (LLOQ) was 3.00 ng/mL, and limit of detection (LOD) was 0.05 ng/mL, with linearity ranging from 3.00 to 500 ng/mL. The results, thus, showed that this method is suitable for application in bioequivalence studies of ranitidine in human plasma.

scholarly journals Determination of Capsaicin and Dihydrocapsaicin in Some Chilli Varieties using Accelerated Solvent Extraction Associated with Solid-Phase Extraction Methods and RP-HPLC-Fluorescence

2012 ◽  
Vol 9 (3) ◽  
pp. 1550-1561 ◽  
Author(s):  
Saksit Chanthai ◽  
Jureerat Juangsamoot ◽  
Chalerm Ruangviriyachai ◽  
Suchila Techawongstien
Keyword(s):  
Solvent Extraction ◽  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Accelerated Solvent Extraction ◽  
Phase Extraction ◽  
Good Precision ◽  
Real Samples ◽  
Relative Standard

Reversed phase-HPLC with fluorescence detection of two major capsaicinoids was described. Isocratic elution using a ratio of methanol and deionized water (66:34, v/v) as mobile phase was used at a flow rate of 0.9 mL/min with well achieved separation within 6 min. Under optimum conditions, their analytical figures of merit for the HPLC method were validated. The linearity was in the range of 1.0-25.0 μg/mL with multiple determination coefficients of higher than 0.995. The limit of detection was ranged of 0.008-0.01 μg/mL. The repeatability and reproducibility of the retention time and peak area for these compounds were in good precision with their relative standard deviations (RSDs) lower than 1% and 5%, respectively. Both capsaicin and dihydrocapsaicin were extracted using an accelerated solvent extraction (ASE) of methanol as an extraction solvent for 5 min static time with 3 cycles. The methanolic extracts were subjected to clean up with C18solid-phase extraction (SPE) with its recoveries ranking of 90.2-98.0%. The method recoveries of real samples were found to be 60.7-98.6%. The optimized extraction method were applied for the determination of the two capsaicinoids in ten vareities of hot chilli pepper samples. Total contents of capsaicinoids were found in the range of 2,307.0-9047.3 μg/g DW with their corresponding Scoville heat unit (SHU) of 34,600-135,700. Additionally, the contents of capsaicinoids using external calibration method comparing with those of standard addition were not significantly different, indicating accuracy of the method. Mostly, the contents of capsaicin found in these real samples were rather higher than those of dihydrocapsaicin.

scholarly journals Solid phase extraction and spectrophotometric determination of palladium with 2-(2-quinolylazo)-5-diethylaminobenzoic acid

2006 ◽  
Vol 71 (7) ◽  
pp. 821-828 ◽  
Author(s):  
Weizu Yang ◽  
Qiufen Hu ◽  
Zhangjie Huang ◽  
Jiayuan Yin ◽  
Gang Xie ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Reversed Phase ◽  
Molar Absorptivity ◽  
Minimal Amount ◽  
Phase Extraction ◽  
Relative Standard ◽  
Alcohol Medium ◽  
Isopentyl Alcohol

A sensitive, selective and rapid method for the determination of palladium based on the rapid reaction of palladium(II) with 2-(2-quinolylazo)-5-diethylaminobenzoic acid (QADEAB) and the solid phase extraction of the Pd(II) -QADEAB chelate with a reversed phase polymer-based C18 cartridge was developed. In the presence of 0.05 - 0.5 mol/L of hydrochloric acid solution and cetyl trimethylammonium bromide (CTAB) medium QADEAB reacts with palladium(II) to form a violet complex with a mole ratio 1:2 (palladium to QADEAB). The chelate was enriched by solid phase extraction with a reversed phase polymer-based C18 cartridge. An enrichment factor of 200 was obtained by elution of the chelate form the cartridge with the minimal amount of isopentyl alcohol. The molar absorptivity of the chelate in the isopentyl alcohol medium was 1.43?105 L mol-1 cm-1 at 628 nm. Beer?s law was obeyed in the range of 0.01-1.2 ?g/mL. The relative standard deviation for eleven replicate samples at the 0.2 ?g/L level was 2.18 %. The attained detection limit amounted to 0.02 ?g/L in the original samples. This method was applied to the determination of palladium in environmental samples with good results.

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