Flask tests

Cripe CR, Walker WW, Pritchard PH, et al. 1987. A shake-flask test for estimation of biodegradability of toxic organic substances in the aquatic environment. Ecotoxicol Environ Safety 14 239-251. 

There are various testing procedures, such as the Warren Spring Rotating Flask test (WSL test, Labofina test). Institute Francais du Petrole flow test (IFF test), Mackay-Nadeau-Steelman test (MNS test), EXDET, and other procedures. 

Comparison of Effectiveness Tests. Three laboratory methods were compared the revised standard dispersant effectiveness test used and required for regulation in the United States, the swirling flask test (developed by Environment Canada), and the IFP-dilution test (used in France and other European countries) [1693]. Six test oils and three dispersants were evaluated. It was concluded that the three tests gave similar precision results, but that the swirling flask test was fastest, cheapest, simplest, and required the least operator skill. 

Results using the swirling flask test for dispersant effectiveness have been reported. Heavy oils show effectiveness values of approximately 1%, medium crude oils of approximately 10%, light crude oils of approximately 30%, and very light oils of approximately 90%. 

Dewar flask tests, adiabatic storage tests (AST)—see Section 2.3.2.2, and... 

Certain equipment configurations allow for the use of Dewar flask testing at elevated pressures. Several arrangements have proved successful such as a sealed glass ampoule in the Dewar flask, a steel pressure vessel in the flask, a Dewar flask in an autoclave under inert gas pressure, and a stainless steel Dewar flask. Dewar flasks provided with an addition line can also be used to study chemical reactions. In Figure 2.21, typical temperature-time curves of Dewar flask experiments are shown. 

From the temperature-time curve, as recorded in a Dewar flask experiment or in an AST, the heat production as a function of time can be determined. Furthermore, from Dewar flask tests with an accurate internal heater or from AST experiments, the specific heat (Cp) can be determined, or in pressurized and closed vessels, the Cv as well. For the heat production, the following equation holds ... 

In addition to the thermal effects of the reaction, pressure data are acquired from an ARC experiment. As in the closed Dewar flask tests, the pressure is the result of (1) the heating of the free-board gas, (2) the vapor pressure, and (3) the reaction-produced gases. With the pressure-temperature versus time curve, the gas generation of the substance can be calculated (mol gas/mol substance). This is possible if enough knowledge of the gas solubility in the liquid and the vapor pressure of the sample are available. Such a calculation is useful for gas venting estimates for the process. 

The stability of powders can be determined by adiabatic storage tests or Dewar flask tests under an air atmosphere (Section 2.3.2.2). Several other dedicated tests have been developed [10,133-136]. 

FIGURE 2.20. Simple Test Setup for a Dewar Flask Test 67... 

Flask tests involve the testing of native soil and groundwater without additives, in which the oxygen uptake (or carbon dioxide produced) is continually monitored. After about 1 to 5 days, the concentration of contaminant is analyzed and compared with the initial concentration. Results indicate the rate of degradation with only oxygen addition, and the quantity of oxygen required per unit of contaminant. 

In a Gledhill-modified version (30) of the Sturm CO2 evolution shake flask test (31). the following nonionic ethoxylates were studied ... 

Other designations for samples are bulk sample, primary sample, secondary sample, subsample, laboratory sample, and test sample. These terms are used when a sample of a bulk system is divided, possibly a number of times, before actually being used in an analysis. For example, a water sample from a well may be collected in a large bottle (bulk sample or primary sample), from which a smaller sample is acquired by pouring into a vial to be taken into the laboratory (secondary sample, subsample, or laboratory sample), then poured into a beaker (another secondary sample or subsample), before a portion is finally carefully measured into a flask (test sample) and diluted to make the sample solution. 

Ingerslev, F., Nyholm, N. (2000) Shake-flask test for determination of biodegradation rates of C-14-labeled chemicals at low concentrations in surface water systems. Ecotoxicol. Environ. Saf. 45, 274-283. 

Determination of the molar volume of a gas barometer, beaker, Erlenmeyer flask, test tubes, graduated cylinder, clamp, analytical balance, thermometer, rubber tubing... 

All-purpose hands and syringe hands, available in a variety of designs, are also required elements of a robotic station. Differently sized objects (e.g. sample flasks, test tubes, probes, hold and press push-buttons) call for different types of hand. A syringe hand facilitates the withdrawal of liquids from vessels. Hand design has benefited from innovations devised by academic research groups [10]. 

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