an extraction-spectrophotometric method for the determination of trace amounts of ammonium ion is described. ammonium ion is effectively extracted as a neutral ternary complex nh . db 18c6. calmagite at ph 3.0 into chloroform, followed by spectrophotometric determination at =48 5 nm. molar absorptivity of the ternary complex at this wavelength is 1.08 10 mol cm . beer's law is obeyed over ...

National Institute for Occupational Safety and Health method 7703 is a portable field procedure for the analysis of workplace air filter samples for hexavalent chromium (CrVI) content immediately after the samples are collected. The field method prescribes CrVI extraction from air filter samples with an ammonium sulfate/ammonium hydroxide extraction buffer using ultrasonic extraction (UE). Stro...

Several liquid-chromatographic systems involving anion-exchange resins and linear acetate gradient elution have been reported previously for the analysis of ultraviolet-absorbing constituents in human urine. We describe a high-performance liquid-chromatographic system on which a macroreticular anion-exchange resin, and stepwise elution are used. Separations were more rapid with ammonium chlorid...

Designed experiments based on a simplex mixture design were employed to explore the effects of three solvent components (water, formic acid, and aqueous acetic acid), extraction time, and extraction temperature for the automated microextraction of basic (cationic) dyes from acrylic fibers. Extractions were conducted by an automated liquid handling system, and dye extraction was evaluated using ...

Background & Aim: A simple and rapid microwave- assisted extraction (MAE) procedure was developed and optimized for the isolation of borneol and bornyl acetate from Ferulago macrocarpa. Ferulago macrocarpa (Apiaceae) is an endemic plant in Iran. Experimental: Dried powdered aerial parts of plants were soaked in water and irradiated with microwave in a Clevenger extraction app...

We present an improved method for ultraviolet spectrophotometry of theophylline in serum. We studied various extraction techniques aimed at eliminating interferences from co-extractable serum constituents. In the resulting modified procedure, 1 ml of serum is required and a salt-solvent pair of ammonium sulfate and chloroform/hexane is used for extraction. The solvent forms the top phase after ...

Anesthetics utilized for the immobilization of pregnant mammals are prone to crossing the placental barrier and cause adverse effects to the fetuses. In this study, we develop a facile method employing high performance liquid chromatography (HPLC) for the study of Telazol crossing the placental barrier of pregnant pigs. The method mainly relies on the efficient extraction strategy that includes...

This work determined that southern yellow pine wood can almost be completely dissolved in the quaternary ammonium ionic liquid tetrabutylammonium acetate with dimethyl sulfoxide (in a 2:8 mass ratio), after minimal grinding, upon heating at 85 °C for three dissolution/reconstitution cycles, each 1.5 h. Approximately 34.6% of the native lignin and 67.4% of the native carbohydrates present in the...

A simple and sensitive high performance liquid chromatographic (HPLC) method was developed for quantification of lacidipine in human plasma. Felodipine was used as an internal standard (IS). The present method used protein precipitating extraction of lacidipine from plasma. Separation was carried out on reversedphase c18 column (250 mm × 4.6 mm, 5μ) and the column effluent was monitored by UV d...

Background: The COVID-19 pandemic affected different aspects of human life seriously, including health issues. Unfortunately, the process RNA extraction using commercial kits is highly expensive. Replacement this technique with a cheaper one may help us catch more affordable approach. Objectives: This study aims to introduce simple and cost-benefit procedure extract nucleic acid from swab sampl...