Solid-Phase Fluorimetric Determination of Tetracyclines in Medicinal Preparations on Cellulose Paper and in Thin-Layer Silica Gel Using a Smartphone

In this research at first palladium nanoparticle attached to a new chemically bonded silica gel has been synthesized and has been characterized with different techniques such as X-ray diffraction (XRD), fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Then, this new sorbent (chemically modified silica gel with N-propylmorpholine (PNP-SBNPM)) was efficiently used for preconcentration of some metal ions in various food samples. The influence of effective variables including mass of sorbent, flow rate, pH of sample solutions and condition of eluent such as volume, type and concentration on the recoveries of understudy metal ions were investigated. Following the optimization of variables, the interfering effects of some foreign ions on the preconcentration and determination of the investigated metal ions described. At optimum values of variables, all investigated metal ions were efficiently recovered with efficiency more than 95%, relative standard deviation (RSD) between 2.4 and 2.8, and detection limit in the range of 1.4–2.7 ng mL−1. The present method is simple and rapidly applicable for the determination of the understudied metal ions (ng mL−1) in different natural food samples.

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Application of microwave-assisted desorption/headspace solid-phase microextraction as pretreatment step in the gas chromatographic determination of 1-naphthylamine in silica gel adsorbent

Talanta ◽

10.1016/j.talanta.2006.09.005 ◽

2007 ◽

Vol 71 (5) ◽

pp. 1993-1997 ◽

Cited By ~ 6

Author(s):

C YAN ◽

J JEN ◽

T SHIH

Keyword(s):

Silica Gel ◽

Solid Phase Microextraction ◽

Solid Phase ◽

Chromatographic Determination ◽

Headspace Solid Phase Microextraction ◽

Microwave Assisted

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Thin Layer Chromatographic Determination of Subsidiary Dyes in D&C Red No. 19 and D&C Red No. 37

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/57.4.961 ◽

1974 ◽

Vol 57 (4) ◽

pp. 961-962

Author(s):

Sandra Bell

Keyword(s):

Thin Layer ◽

Silica Gel ◽

Chromatographic Method ◽

Chromatographic Determination

Abstract A thin layer chromatographic method is presented by which triethylrhodamine and other lower ethylated subsidiary colors are separated from D&C Red No. 19 and D&C Red No. 37. After removal from the plate, subsidiary dyes are extracted from silica gel C adsorbent and quantitated spectrophotometrically. Recoveries of 1, 2, and 5% of added triethylrhodamine ranged from 89 to 1 0 3% for D&C Red No. 19 and from 85 to 1 0 2% for D&C Red No. 37.

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Thin Layer Chromatographic Determination of Citrinin

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/62.1.201 ◽

1979 ◽

Vol 62 (1) ◽

pp. 201-202 ◽

Cited By ~ 2

Author(s):

Robert D Stubblefield

Keyword(s):

Acetic Acid ◽

Thin Layer ◽

Linear Relationship ◽

Silica Gel ◽

Coefficient Of Variation ◽

Ethylenediaminetetraacetic Acid ◽

Limit Of Detection ◽

Chromatographic Determination ◽

Tlc Plates

Abstract Clearly defined zones of citrinin can be obtained on thin layer chromatographic (TLC) plates and measured by fluorodensitometry. Silica gel plates were prepared as a slurry with aqueous 0.05M Na2EDTA (ethylenediaminetetraacetic acid), spread at 0.5 mm wet thickness, and activated at 105°C for 1 hr. Plates were developed in acetic acid-benzene (5+95). The limit of detection was 10 ng citrinin/zone. Densitometric analysis (365 nm excitation, 505 nm emission) revealed that a linear relationship exists for levels of 10 ng to at least 100 ng/zone wtih a coefficient of variation of ±5%.

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Identification and Quantitation of Polymyxin B, Framycetin, and Dexamethasone in an Ointment by Using Thin-Layer Chromatography with Densitometry

Journal of AOAC International ◽

10.1093/jaoac/88.5.1549 ◽

2005 ◽

Vol 88 (5) ◽

pp. 1549-1554 ◽

Cited By ~ 8

Author(s):

Jan Krzek ◽

Anna Maślanka ◽

Pawel Lipner

Keyword(s):

Thin Layer ◽

Silica Gel ◽

Polymyxin B ◽

Rapid Identification ◽

Mobile Phases ◽

Relative Standard ◽

Dexamethasone Acetate ◽

Similar Accuracy ◽

Layer Chromatography

Abstract A new thin-layer chromatographic-densitometric method has been developed for rapid identification and quantitative determination of polymyxin B, framycetin, and dexamethasone in a dental ointment. Silica gel 60 and F254 silica gel 60 plates were used for separating antibiotics and dexamethasone acetate, respectively. When determining framycetin and polymyxin B, chromatograms were developed by using 2 mobile phases, namely methanol and methanol–n-butanol–ammonia (25%)–chloroform (14 + 4 + 9 + 12, v/v/v/v/). The densitometric measurements were made at 550 nm after detection with 0.3% ninhydrin solution. Dexamethasone was determined by using the mobile phase cyclohexane–ethyl acetate (2 + 3, v/v) and ultraviolet densitometric recording at 245 nm. The results obtained for individual constituents with the chromatographic-densitometric method demonstrate similar accuracy, relative standard deviation values from 1.49 to 2.47%, and relative error values from 0.02 to 0.81% and are comparable to those obtained with the reference methods.

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Quantitative Determination of Tris-(2,3,-dibromopropyl) Phosphate by Densitometry of Thin Layer Chromatograms

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/62.6.1315 ◽

1979 ◽

Vol 62 (6) ◽

pp. 1315-1318

Author(s):

Albert M Gardner

Keyword(s):

Sewage Sludge ◽

Thin Layer ◽

Quantitative Determination ◽

Ethyl Acetate ◽

Silver Nitrate ◽

Flame Retardant ◽

Silica Gel ◽

White Background ◽

Ppm Level

Abstract The flame retardant tris-(2,3-dibromopropyl) phosphate (Tris) was chromatographed on silica gel thin layer plates, using ethyl acetate-hexane (30+70) as the developing solvent. Tris was visualized by spraying the chromatogram with 1% aqueous silver nitrate followed by exposure to ultraviolet light for 40 min. Tris appeared as dark gray spots on a white background; the spots were quantitated by densitometry at 600 nm. The lower level of sensitivity was 50 ng; calibration plots were linear from 50 to 800 ng. The procedure was developed to determine the levels of unmetabolized Tris remaining after exposure to sewage sludge suspensions. Recovery of Tris from 3 sewage sludge samples fortified at the 1.0 ppm level averaged 97%.

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

Journal of Spectroscopy ◽

10.1155/2013/548345 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 7

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.

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