Rinse elimination

Rinse the precipitate with several portions of hot distilled water (Figure 3.8). To test for sufficient rinsing (elimination of all residual chloride from the excess barium chloride, HC1, and possibly the sample), collect some of the most recent washings in a test tube and add two drops of silver nitrate solution. If a white precipitate (cloudy appearance) forms, more rinsing is required before proceeding to step 13. Continue to rinse and test until the rinsings are clean. 

IC - suppressed conductivity Matrix rinse elimination Primary and confirmatory columns 314.1 lonPac AS16 + AS20 lonPac ASH Hydroxide 0.03... 

Chem. Descrip. Phosphoric acid, inhibiting tensides Uses Acidic cleansing agent with anticorrosion and neutralizing props, for initial and final rinsing eliminates caldum deposits Properties Liq. 

Many facilities in this industry use in-plant technology to reduce or eliminate the waste load, requiring end-of-pipe treatment and thereby improve the quality of the effluent discharge and reduce treatment costs. In-plant technology involves water reuse, process material conservation, reclamation of waste enamel, process modifications, material substitutions, improved rinse techniques, and good housekeeping practices.3-615... 

The rinse between a soak cleaner and an electrocleaner may be eliminated if the two baths are compatible. 

A modified version of this program for 2-aminothiazole synthesis was executed. In that version, the initial exposure to 20% piperidine was eliminated, and all delivered volumes were reduced to 3.75 mL. After completion of the synthesis, the resin was dried under vacuum. Aqueous TFA (95%, 5 mL) was added and the tube was heated at 50°C for 4h (note 7). The cleavage solution and two subsequent rinses of the resin (one of 5 mL of 95% aqueous TFA and one of 5mL of MeOH) were combined and evaporated to dryness with a Speedvac. 

This flask must be cleaned with h ot chromic acid solution and then, along with all other glassware used in this preparation, soaked in a base solution, rinsed with distilled waiter, and oven dried. Thermal rearrangement of the intermediate vinyl ether in a new (untreated) flask resulted in elimination. 

Once all of the precipitate has been transferred to the funnel, rinse it three more times with the NH4N03 solution. Test for chloride in the filtrate by acidifying a few millifiters of the most recent rinsings with dilute HN03 and adding AgN03 dropwise, as done in Experiment 6, step 11. Continue to rinse until all chloride is eliminated. 

Give your EDTA solution one final shake to ensure its homogeneity. Then, clean a 50-mL buret, rinse it several times with your EDTA solution (the titrant), and fill, as usual, with your titrant. Be sure to eliminate the air bubbles from the stopcock and tip. Titrate the solutions in your flask, one at a time, until the last trace of red disappears in each with a fraction of a drop. This final color change will be from a violet color to a deep sky blue, but should be a sharp change. All three titrations should agree to within 0.05 mL of each other. If they do not, repeat until you have three that do. Record all readings in your notebook. 

---