Ultra-trace monitoring of copper in environmental and biological samples by inductively coupled plasma atomic emission spectrometry after separation and preconcentration by using octadecyl silica membrane disks modified by a new schiff's base

Ultra-trace amounts of Cu(II) were separated and preconcentrated by solid phase extraction on octadecyl-bonded silica membrane disks modified with a new Schiff,s base (Bis- (2-Hydroxyacetophenone) -2,2-dimethyl-1,3-propanediimine) (SBTD) followed by elution and inductively coupled plasma atomic emission spectrometric detection. The method was applied as a separation and detection method for copper(II) in environmental and biological samples. Extraction efficiency and the influence of sample matrix, flow rate, pH, and type and minimum amount of stripping acid were investigated. The concentration factor and detection limit of the proposed method are 500 and 12.5 pg mL-1, respectively.

Som alla dar V

Soitinnus: naiskuoro, kitara, alttoviulu, sello.

Avaliação da concentração de retinol em leite UHT ("Ultra High Temperature") comercializado em Natal, Rio Grande do Norte

Deficiency of micronutrients is a public health problem. Cow milk is a source of retinol. The objective of this study is to evaluate the retinol concentration in milk commercialized in Natal/RN. Ten samples were taken of each brand of UHT milk. Vitamin content was determined by HPLC using the Shimadzu LC-10 AD Chromatograph, coupled to the Shimadzu SPD 10 A UV-VIS Detector and the Shimadzu C-R6A Chromatopac Integrator with Shim-pack CLC-ODS (M) column, measuring 4.6 mm x 25 cm. The mobile phase was 100% methanol, with a flow of 1 mL/min. The mean retinol concentration varied between 22.7 ± 4.9 µg/100 mL and 44.1 ± 4.1 µg/100 mL, with the differences statistically significant (p<0.001). Only one of the 7 brands had retinol concentration below the normal requirements for human consumption.

Om det, som bör i achttagas wid belägenheten af en landt-gård

Invocatio: I.J.N.

Oförgripeliga tanckar om den wärkan som et lands upodling har på dess climat

Invocatio: I.J.N.

Om caffé och de inhemska wäxter, som pläga brukas i des ställe

Invocatio: I.J.N.

O estado da arte da cromatografia líquida de ultra eficiência

Ultra Performance Liquid Chromatography (UPLC) retains the same principles as High Performance Liquid Chromatography (HPLC), but uses 1-2.1 mm i.d. columns with sub-2 µm particles. It is considered the newest advance in analytical separation science. The use of these small particles with mobile phases at high linear velocities increases resolution and detectability and decreases analysis time. Thus, the analyses are faster, the solvent volume is smaller, the efficiency is higher and the detectability is 2-3 times higher when compared with HPLC analysis.

Om det, som bör i achttagas, wid en stads anlägning

Invocatio: I.J.N.

Om den skada, som kjölden tilfogar åker- och trägårds skötseln i Finland

Invocatio: Med Guds Hjelp.

Om nyttan, som kunnat tilfalla wart kjära fädernesland, af des nybygge i America, fordom Nya Swerige kalladt

Invocatio: Med Guds wälsignande nåd och wederbörandes tilstånd yttrade tankar.

Om nyttan som England kan hafwa af sina nybyggen i norra America

Inv: Med Guds Hjelp.

Om nyttan, som tilfaller en province af en deri anlagd stapelstad

Painovuosi nimekkeestä.

Oral history som tvärvetenskap : : rapport från konferensen Oral history - the Art of dialogue : 8.-10.11.2007 Jagiellonska universitetet Krakow

Ajankohtaista

Minnen från Skatudden, eller, Det Helsingfors som går / pennteckningar af Rud. Wald. Åkerblom

Kuvateos sisältää viisi painokuvaa Rudolf Waldemar Åkerblomin piirustuksista, jotka ovat tallentaneet 1800-luvun lopulla katoamassa ollutta Helsinkiä: Katajanokan puutaloja ja vinoon painuneita hökkeleitä.

Att studera det svenska i Finland som ett pussel

Ajankohtaista