A Green Analytical Method Using Polyurethane Foam for The Extraction and Determination of Lauryl Ether Sulfate in Personal Care Hygiene Products

Shower Gel ◽

A green methodology was developed for the extraction and determination of lauryl ether sulfate in raw materials and commercial liquid soap and shower gel samples. The method avoids the use of organic solvents, offering a simple, cheap, and safe analysis. The methodology is based on the sorption of an ionic pair consisting of a cationic dye and an anionic surfactant onto polyurethane foam. The experimental variables were optimized by chemometry to obtain the conditions that maximized extraction of the ionic pair. Digital imaging and spectrophotometry were used for quantification in the linear concentration range from 10.0 to 100 mg L-1. The limits of detection and quantification were, respectively, 2.71 and 9.28 mg L-1 for digital imaging, and 1.74 and 5.83 mg L-1 for spectrophotometry. The methods showed good results when applied to commercial samples, with recoveries in the range 96.8-103%.

Quantitative Determination of Azithromycin in Human Plasma by Liquid ChromatographyMass Spectrometry and its Application in Pharmackokinetic Study

Dhaka University Journal of Pharmaceutical Sciences ◽

10.3329/dujps.v11i1.12488 ◽

2012 ◽

Vol 11 (1) ◽

pp. 55-63 ◽

Cited By ~ 3

Author(s):

Maizbha Uddin Ahmed ◽

Mohammad Safiqul Islam ◽

Tasmin Ara Sultana ◽

AGM Mostofa ◽

Muhammad Shahdaat Bin Sayeed ◽

...

Keyword(s):

Mobile Phase ◽

Solid Phase ◽

Internal Standard ◽

Extraction Process ◽

Serum Samples ◽

Limit Of Quantification ◽

Relative Standard ◽

Azithromycin is an effective and well-known antimicrobial agent. In the present study, a simple, sensitive and specific LC/MS/MS method has been developed and validated for the quantification of Azithromycin in human serum samples using Clarithromycin as internal standard. Azithromycin was extracted from biological matrix by using solid phase extraction process. The chromatographic separation was performed on Luna C18 (3 ?, 2x150 mm) column with a mobile phase consisting of 35 mM ammonium acetate buffer (mobile phase-A) and acetonitrile and methanol in ratio of 90:10 ( as mobile phase-B) at a flow rate of 0.25 mL/min. The method was validated over a linear concentration range of 0.5?50.0 ng/mL and limit of quantification (LOQ) was 0.5 ng/mL with a coefficient of correlation (r2) = 0.9998. The intra-day and inter-day precision expressed as relative standard deviation were 1.64% 8.43% and 2.32% 9.92%, respectively. The average recovery of azithromycin from serum was 98.11%. The method was successfully applied to a pharmacokinetic study after oral administration of Azithromycin 200 mg/5 ml suspension in healthy Bangladeshi volunteers. DOI: http://dx.doi.org/10.3329/dujps.v11i1.12488 Dhaka Univ. J. Pharm. Sci. 11(1): 55-63, 2012 (June)

Use of a Ruthenium(III), Iron(II), and Nickel(II) Hexacyanometallate-Modified Graphite Electrode with Immobilized Oxalate Oxidase for the Determination of Urinary Oxalate

Journal of AOAC International ◽

10.1093/jaoac/84.6.1927 ◽

2001 ◽

Vol 84 (6) ◽

pp. 1927-1933 ◽

Cited By ~ 4

Author(s):

Stjepan Milardović ◽

Zorana Grabarić ◽

Vlatko Rumenjak ◽

Nenad Blau ◽

Dražen Milošević

Keyword(s):

Ethylenediaminetetraacetic Acid ◽

Graphite Electrode ◽

Oxalate Oxidase ◽

Urine Samples ◽

Daily Routine ◽

Urinary Oxalate ◽

Catalyzed Oxidation ◽

Abstract This paper describes the performance of a biosensor with an Ru(III), Ni(II), and Fe(II) hexacyanometallate-modified graphite electrode and immobilized oxalate oxidase for the determination of urinary oxalate. The addition of ruthenium enhances the electrochemical reversibility and chemical stability of the electrocrystallized layer and improves the sensitivity of the biosensor. Hydrogen peroxide, produced by the enzyme-catalyzed oxidation of oxalate, was measured at −50 mV vs an Hg|Hg2Cl2|3M KCl electrode in a solution of pH 3.6 succinic buffer, 0.1M KCl, and 5.4mM ethylenediaminetetraacetic acid. The linear concentration range for the determination of oxalate was 0.18–280 μM. The recoveries of added oxalate (10–35 μM) from aqueous solution ranged from 99.5 to 101.7%, whereas from urine samples without oxalate (or with a concentration of oxalate below the detection limit) the recoveries of added oxalate ranged from 91.4 to 106.6%. The oxalate in 24 h urine samples, taken during their daily routine from 35 infants and children, was measured and found to range from 0.6 to 121.7 mg/L. There were no interferences from uric acid, acetylsalicylic acid, and urea in the concentration range investigated, but paracetamol and ascorbic acid did interfere. A good correlation (R2 = 0.9242) was found between values obtained for oxalate in real urine samples by 2 laboratories, with the proposed biosensor and ion chromatography, respectively.

Determination of Surfactant Sodium Lauryl Ether Sulfate by Ion Pairing Chromatography with Suppressed Conductivity Detection

Journal of Liquid Chromatography ◽

10.1080/10826079408013602 ◽

1994 ◽

Vol 17 (19) ◽

pp. 4087-4097 ◽

Cited By ~ 15

Author(s):

Ming Y. Ye ◽

Ron G. Walkup ◽

Kim D. Hill

Keyword(s):

Ion Pairing ◽

Conductivity Detection ◽

Sodium Lauryl Ether Sulfate ◽

Ether Sulfate ◽

Lauryl Ether ◽

Suppressed Conductivity Detection

Quantitative colorimetric determination of urinary p-aminophenol with an automated analyzer

Clinical Chemistry ◽

10.1093/clinchem/43.4.627 ◽

1997 ◽

Vol 43 (4) ◽

pp. 627-634 ◽

Cited By ~ 10

Author(s):

Jan F Van Bocxlaer ◽

Karine M Clauwaert ◽

Willy E Lambert ◽

André P De Leenheer

Keyword(s):

Colorimetric Method ◽

Stability Study ◽

Colorimetric Determination ◽

Manganese Ions ◽

Significant Interference ◽

Related Compounds ◽

Health Screen ◽

Abstract We developed an automated colorimetric method for the quantitative determination of p-aminophenol with a Cobas Mira analyzer. The procedure can be used for the biological monitoring of human exposure to aniline. An absorbed aniline dose is extensively oxidized to p-aminophenol, which is excreted in urine mainly as glucurono- and sulfo- conjugates. After enzymatic hydrolysis, we reacted the free compound with resorcinol in the presence of manganese ions to form an indophenol dye, which is measured at 550 nm. Excellent accuracy (102.8%, 103.9%, and 96.8% at 2.5, 50, and 90 mg/L, respectively) and precision (7.7%, 2.1%, and 0.8% CV for within-run and 11.1%, 4.7%, and 4.6% for total reproducibility at 2.5, 50, and 90 mg/L, respectively) were achieved over a linear concentration range of 2.0 to 100 mg/L. The detection limit was 0.9 mg/L and no significant interference (except for o-aminophenol) was found for several investigated drugs and related compounds. The proposed method was used for a stability study and to analyze several samples from an occupational health screen.

Determination of PCB Residues in Vegetables by GC-MS

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.487.724 ◽

2012 ◽

Vol 487 ◽

pp. 724-729 ◽

Cited By ~ 1

Author(s):

Tie Bing Liu ◽

Hai Yun Tu ◽

Li Ming Han ◽

Qiu Ping Yuan ◽

Greg Duns

Keyword(s):

High Speed ◽

Polychlorinated Biphenyl ◽

Solid Phase ◽

Simultaneous Detection ◽

Qualitative And Quantitative ◽

Relative Standard ◽

Combination Of Methods ◽

This paper examines a method for the simultaneous detection of 12 different dioxin-like polychlorinated biphenyl (PCB) residues in vegetables. A qualitative and quantitative determination of PCB residues in vegetables was undertaken by a combination of high-speed freezing centrifugation, solid phase extraction, purification, concentration, and GC- MS and GC-ECD. From this combination of methods, 12 different PCBs were detected in vegetables over a linear concentration range of 0.001 to 2 µ g/L (ppb), with detection limits ranging from 0.4ppb to 0.5 ppb, a linear correlation coefficient of 0.99, recoveries ranging from 96.25%-117.5%, and a relative standard deviation ≤ 21%(RSD) .

Europium-(7-carboxymethoxy-4-methyl coumarin)2 Complex based Electrochemical Probe for DNA based on the Interaction between Them

Journal of New Materials for Electrochemical Systems ◽

10.14447/jnmes.v20i4.445 ◽

2017 ◽

Vol 20 (4) ◽

pp. 189-195 ◽

Cited By ~ 2

Author(s):

Belal Hussein ◽

Moustafa Gouda ◽

Walid Fathall ◽

Sherin Arabi

Keyword(s):

Cyclic Voltammetry ◽

Ternary Complex ◽

Volume Fraction ◽

Differential Pulse ◽

Ternary Complexes ◽

Water Mixture ◽

Binary And Ternary Complexes ◽

The interaction of Eu(III) ion with 7-carboxymethoxy-4-methylcoumarin (CMMC) has been investigated using the potentiometric method in the ethanol-water mixture solvent (0.15 volume fraction). The formation of the different binary, ternary complexes is confirmed by the corresponding pH-potentiometric curves. SUPERQUAD computer program has been used for the refinement of all the calculated constants in our present study. Electroanalytical techniques have been used to confirm the formation of different binary and ternary complexes under investigation. The binding constant of the ternary complex Eu(III)-CMMC-DNA calculated by cyclic voltammetry (CV) and differential pulse (DP) was found to be 1.8 and 2.5x 105 M-1 in Tris-HCl, respectively. The changes in the current intensity have been used for the quantitative determination of DNA over a linear concentration range with LOD of 1.0-1.3 µg/ ml in 0.1 M Tris-HCl buffer.

AN IMPROVED LC-MS/MS METHOD DEVELOPMENT AND VALIDATION FOR THE DETERMINATION OF TRANDOLAPRIL AND VERAPAMIL IN HUMAN PLASMA

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2019v11i3.31247 ◽

2019 ◽

pp. 91-95

Author(s):

YATHA RAVI ◽

B. RAJKAMAL

Keyword(s):

Method Development ◽

Solid Phase ◽

Internal Standard ◽

Biological Matrix ◽

Method Development And Validation ◽

Ionization Mode ◽

Development And Validation ◽

Objective: A simple, sensitive and rapid LC-MS/MS technique was developed for the quantitation of trandolapril (TDL) and verapamil (VPL) in a biological matrix and validated. Methods: Sample preparation processed by SPE (Solid Phase extraction) on phenomenex cartridge using Ledipasvir as an internal standard. Two drugs were eluted on waters symmetry-RP18 (5µ, 150 mm×4.0 mm) column with the mobile composition of 10 mmol ammonium formate and ACN(acetonitrile) in the ratio of 70:30 %V/V. Detection and quantitation were processed by electrospray ionization in positive ionization mode. Results: The quantification approach was validated in 5-1500 ng/ml linear concentration range for TDL and 1-2000 ng/ml for VPL. The intraday and inter-day precision and accuracy were found to be 0.58% to 5.69% and 93% to 104% for two drugs. The average recoveries for TDL and VPL were found to be 92.9% and 93.5% respectively. Conclusion: The developed work was validated and can be applicable to the routine analysis of TDL and VPL simultaneously in a biological matrix.

A Multifunctional N-Doped Cu–MOFs (N–Cu–MOF) Nanomaterial-Driven Electrochemical Aptasensor for Sensitive Detection of Deoxynivalenol

Molecules ◽

10.3390/molecules26082243 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2243

Author(s):

Xiaoyan Wen ◽

Qingwen Huang ◽

Dongxia Nie ◽

Xiuying Zhao ◽

Haojie Cao ◽

...

Keyword(s):

High Sensitivity ◽

Food Samples ◽

Electrical Signal ◽

Hazardous Substances ◽

Electrochemical Aptasensor ◽

Signal Probe ◽

Sensitive Determination ◽

Deoxynivalenol (DON) is one of the most common mycotoxins in grains, causing gastrointestinal inflammation, neurotoxicity, hepatotoxicity and embryotoxicity, even at a low quantity. In this study, a facile electrochemical aptasensor was established for the rapid and sensitive determination of DON based on a multifunctional N-doped Cu-metallic organic framework (N–Cu–MOF) nanomaterial. The N–Cu–MOF, with a large specific surface area and good electrical conductivity, served not only as an optimal electrical signal probe but also as an effective supporting substrate for stabilizing aptamers through the interactions of amino (-NH2) and copper. Under the optimal conditions, the proposed sensor provided a wide linear concentration range of 0.02–20 ng mL−1 (R2 = 0.994), showing high sensitivity, with a lower detection limit of 0.008 ng mL−1, and good selectivity. The sensor’s effectiveness was also verified in real spiked wheat samples with satisfactory recoveries of 95.6–105.9%. The current work provides a flexible approach for the rapid and sensitive analysis of highly toxic DON in food samples and may also be easily extended to detect other hazardous substances with alternative target-recognition aptamers.

TEKNIK VOLTAMETRI PELUCUTAN ANODIK GELOMBANG PERSEGI UNTUK PENENTUAN KADAR LOGAM Cu DALAM KANGKUNG AIR

Jurnal Kimia Riset ◽

10.20473/jkr.v1i2.3094 ◽

2016 ◽

Vol 1 (2) ◽

pp. 122

Author(s):

Irdhawati Irdhawati ◽

Liana Sari ◽

Ida Ayu Raka Astiti Asih

Keyword(s):

Limit Of Detection ◽

Anodic Stripping Voltammetry ◽

Stripping Voltammetry ◽

Water Spinach ◽

Square Wave ◽

Anodic Stripping ◽

Standard Solution ◽

ABSTRAK Analisis logam berat Cu(II) dilakukan dengan metode voltametri pelucutan anodik gelombang persegi. Penelitian ini bertujuan untuk mengetahui validitas metode voltametri pelucutan anodik yang digunakan dalam pengukuran kadar logam Cu(II) dalam sampel kangkung air di muara sungai Badung. Elektroda glassy carbon digunakan sebagai elektroda kerja, Ag/AgCl sebagai elektroda pembanding, dan kawat platina sebagai elektroda pembantu. Parameter yang dioptimasi meliputi waktu deposisi dan laju pindai dalam larutan standar Cu(II) 500 ppb. Validasi metode ditentukan dengan menentukan rentang konsentrasi linier, limit deteksi, keberulangan pengukuran, dan persen perolehan kembali. Teknik voltametri pelucutan anodik kemudian digunakan untuk mengukur kadar logam Cu(II) pada sampel kangkung air.Hasil optimasi pengukuran kadar logam Cu(II) yaitu waktu deposisi optimum 60 detik dan laju pindai optimum 10 mV/detik. Pengukuran validitas larutan standar logam Cu(II), rentang konsentrasi linier larutan 50 ~500 ppb dan memiliki nilai koefisien korelasi 0,9983. Limit deteksi 35 ppb, keberulangan pengukuran memiliki rasio Horwitz kurang dari 2, dan persen perolehan kembali 99,35% ± 0,4526. Hasil pengukuran sampel tanaman kangkung memiliki kandungan logam Cu(II) sebesar 4,0 ppm. Berdasarkan Keputusan Direktur Jenderal Pengawasan Obat dan Makanan batas maksimum cemaran logam dalam makanan untuk logam Cu(II) adalah 5,0 ppm. Oleh karena itu dapat diketahui bahwa kandungan logam Cu(II) tidak melebihi kadar maksimum yang diperkenankan. Kata Kunci : logam berat, voltametri pelucutan anodik gelombang persegi, kangkung airABSTRACTHeavy metal analysis of Cu(II) was measured by square wave anodic stripping voltammetry method. The aim of this research is to know the validity of square wave anodic stripping voltammetry method for determination of Cu(II) in water spinach from the estuary of Badung river. Glassy carbon, Ag/AgCl, and Pt wire electrodes were used as working electrode, reference electrode and counter electrode, respectively. Optimized parameter involved the deposition time and scan rate in standard solution Cu(II) 500 ppb. Furthermore, the validation method was examined by determination of linear concentration range, limit of detection, repetition of measurement, and percent of recovery. Moreover, the result of validation was used for observing of heavy metal Cu(II) content in water spinach. The result of optimum deposition time is 60 s. Meanwhile, the scan rate optimum is 10 mV/s. Measurement for standard solution 50 ~ 500 ppb on linear concentration range, with correlation coefficient 0,9983. Limit of detection is 35 ppb, repetition of measurement for metal has Horwitz ratio less than 2, and percent recovery of Cu(II) measurement is 99,35% ± 0,4526. The measurement of Cu(II) content in the water spinach sample contain Cu(II) 4,0 ppm. Based on Decree of Directorate General for Drug and Food Control, the treshold line for Cu(II) contamination for food is 5,0 ppm. Therefore, the water spinach sample contain Cu(II) is less than accepted value. Keyword : Heavy metal, square wave anodic stripping voltammetry, water spinach

New Reagent of Coupling Reaction for Spectrophotometric Determination of Paracetamol in Pharmaceutics

Oriental Journal Of Chemistry ◽

10.13005/ojc/370416 ◽

2021 ◽

Vol 37 (4) ◽

pp. 885-890

Author(s):

Kurdistan F. Azeez ◽

Tara F. Tahir ◽

Dashne M. Kokhasmail

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

High Performance ◽

Regression Coefficient ◽

Coupling Reaction ◽

Molar Absorptivity ◽

Good Agreement ◽

New reagent 2- hydroxybenzaldehydewas used in a coupling reaction for determination of paracetamol via spectrophotometric method. The proposition of simplicity, inexpensive, rapidity and sensitivity were conducted via spectrophotometric procedure. The method was based on diazotization of paracetamol and coupling with 2-hydroxybenzaldehyde in alkaline medium. Linear concentration range (0.50 - 12.00) µg/ml was comply Beer’s law at maximum wavelength 444 nm and detection limit (LOD) 0.05 µg/ml. The molar absorptivity and regression coefficient of (R2) were 1.2032×104 l/mol.cm, 0.9995, respectively. The suggested method was profitablyadapted for the determination of paracetamol in pharmaceutics. The results attained were in good agreement with thatone by standard method high performance liquid chromatography (HPLC).