Samples emulsions

LLE has been used in the past for the extraction of pesticides from environmental water samples [17]. However, its application in the extraction of waste-water samples is scarce due to the low efficiency of extraction, especially for polar analytes. Because of the vast amount of surfactants and natural products present in wastewater samples, emulsions are formed which complicate the process of extraction and lead to low extraction recoveries. However, there have been some useful applications of LLE to wastewater analyses. For example, LLE was found to be effective for the isolation of herbicide and pesticide organic compounds from industrial wastewater samples and also from complex matrices [18]. 

We studied electrochemically induced ET between a ferrocene derivative (FeCp-X) in single oil droplets and hexacyanoferrate(III) (Fe(III)) in the surrounding water phase the reaction system is schematically illustrated in Figure 11 [50,74], Tri-n-butyl phosphate (TBP) containing FeCp-X (ferrocene [X = H] or decamethylferrocene [X = DCM]), a fluorescent dye (perylene [Pe 0.5 mM] or 9,10-diphenylanthracene [DPA 10 mM]), and TBA+TPB (lOmM) is dispersed in an aqueous solution containing TBA+Cr, MgS04 (0.1 M), and potassium hexacyanoferrate(II) (Fe(II) 0.2 mM) with a 1 500 (oil/water) weight ratio as a sample emulsion. 

Fill the sample container with sample emulsion and seal hermetically. 

Continuous phase Dispersed phase Sample emulsion... 

Repeat with sample emulsion to determine its density (p). 

Sample emulsion Glass cylinder Environmental chamber Ruler... 

Fill glass cylinder with sample emulsion. 

Liquid-liquid extractions are very useful but have certain limitations. The extracting solvents are limited to those that are water immiscible (for aqueous samples). Emulsions tend to form when the solvents are shaken, and relatively large volumes of solvents are used that generate a substantial waste disposal problem. The operations are often manually performed and may require a back extraction. 

Temperatures are not obtained directly by DSC. The problem is to determine the sample emulsion temperature Ts knowing the temperature Tp of the oven. 

Fig. 1. Absorbance spectrum for the OB-2 crude oil sample emulsion in the vicinity of the vanadium secondary line at 305.633nm, with a pyrolysis temperature of 1000 °C,...

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