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Measurement of Electrolytic Conductance
Published in Grinberg Nelu, Rodriguez Sonia, Ewing’s Analytical Instrumentation Handbook, Fourth Edition, 2019
Stacy L. Gelhaus, William R. LaCourse
IC is a special form of liquid chromatography (covered in Chapter 22), and thus, modern HPLC equipment, with proper accessories, can be used for IC. IC was first reported in 1975 by Small et al.27Figure 19.11 shows, schematically, the arrangement of parts in a typical ion chromatograph. The unique contribution of these authors was the use of a “suppressor column,” which is a second ion-exchange column to react with the ions of the eluent. They also used a sensitive small-volume conductivity cell as a detector to measure only the conducting analyte ions in the sample. Conductivity is a nonspecific measurement and cannot distinguish between the eluent and sample ions. Sensitivities in the micrograms per liter (parts per billion) range may be achieved. The detection of inorganic ions can be accomplished with either chemical or electronic suppression.
Manure Characteristics
Published in Frank R. Spellman, Nancy E. Whiting, Environmental Management of Concentrated Animal Feeding Operations (CAFOs), 2007
Frank R. Spellman, Nancy E. Whiting
Occasionally, the concentration is expressed as a percent. A 1% concentration equals 10,000 ppm. Very low concentrations are sometimes expressed as micrograms per liter (ng/L). A microgram is 1 millionth of a gram.
Bioactivities and phenolic composition of Limonium boitardii Maire and L. cercinense Brullo & Erben (Plumbaginaceae): two Tunisian strict endemic plants
Published in International Journal of Environmental Health Research, 2022
Ons Sefi, Soumaya Bourgou, Wided Megdiche-Ksouri, Mohamed Libiad, Abdelmajid Khabbach, Mohamed El Haissoufi, Fatima Lamchouri, Nikos Krigas, Zeineb Ghrabi-Gammar
The identification of natural products was done using high performance liquid chromatography system (consisting of a vacuum degasser, an autosampler and a binary pump with a maximum pressure of 400 bar; Agilent 1260, Agilent technologies, Germany) equipped with a reversed phase C18 analytical column of 4.6 × 100 mm and 3.5 μm particle size (Zorbax Eclipse XDB C18). The diode array detector was set to a scanning range of 200–400 nm. Column temperature was maintained at 25°C. The injected sample volume was 2 μl, and the flow rate of mobile phase was 0.4 mL/min. The mobile phase consisted of a mixture of solvent A (methanol) and solvent B (milli-Q water with 0.1% formic acid). The optimized gradient elution was illustrated as follows: 0–5 min, 10–20% A; 5–10 min, 20–30% A; 10–15 min, 30–50% A; 15–20 min, 50–70% A; 20–25 min, 70–90% A; 25–30 min, 90–50% A; 30–35 min, return to initial conditions. Identification analysis of phenolic compounds was done by comparison of their retention time with those of pure standards. Phenolic acids standards were as follows: gallic, chlorogenic, syringic, synapic and ellagic acids, while flavonoids standards were as follows: myricetin, myricetin 3-O-β-D galatopyranoside, myricetin 3-O-α-L-rhamnoside, catechin, epigallocatechin-3-O-gallate, luteolin 7-O- glucoside, rutin, quercetin and kaempferol. For the quantitative analysis, a calibration curve was performed for each identified phenolic compound using the available standards at 280 nm. The amount of each compound was expressed as microgram per gram of residue (µg/g DR).
Comparison of Distichlis spicata and Suaeda aegyptiaca in response to water salinity: Candidate halophytic species for saline soils remediation
Published in International Journal of Phytoremediation, 2018
Mohammad R. Sabzalian, Soleyman Dayani, Mehran Torkian, John E. Leake
The leaf proline content was determined according to Bates et al. (1973). About 0.5 g of fresh plant material was homogenized in a mortar and pestle with 10 ml of 3% aqueous sulfosalicyclic acid. Then, the homogenate was filtered through Whatman No. 1 filter paper. Two ml of the filtrate extract were collected in capped test tubes, and 2 ml of acid ninhydrin solution and 2 ml of glacial acetic acid were added to each sample. The mixture was incubated for an hour at 100°C in water bath. Then, the test tubes were transferred to an ice bath to terminate the reaction. Four ml of toluene was added, and the test tubes were vigorously stirred for 20 s to separate the aqueous phases. The upper phase containing dissolved proline in toluene was collected by separating funnel. The absorbance was measured at 520 nm with a spectrophotometer instrument (Rayleigh-UV 1601, EnviSense, Poland) using a toluene blank. The proline content was determined from a standard curve with proline, and expressed in microgram/gram of fresh weight.
Surface tension measurement of normal human blood samples by pendant drop method
Published in Journal of Medical Engineering & Technology, 2020
Siddharth Singh Yadav, Basant Singh Sikarwar, Priya Ranjan, Rajiv Janardhanan, Ayush Goyal
Normal blood samples with and without anticoagulant were collected from Amity health centre. Firstly, haematocrit is measured by HemataSTAT® II. Samples of Haematocrit (≥38%) are considered in present studies. Temperature regulation (20, 25, 30, 35 and 40 °C) is achieved using shaker which operates at low frequency inside environmental chamber for Blood samples. Before loading samples to micro-fluidic system, blood density is measured by automatic microgram weighing machine. Further, temperature, relative humidity, haematocrit, and density of blood are recorded. The matrix of healthy blood samples collected is given in Table 3.