Analytical Flow Solution Recipes

Replaced by: Analytical Flow Solution Recipes

In use from 2004-06-22

Abstract

Instructions for mixing and handling reagents for use with the OI Analytical Flow Solution IV analyzer

Protocol

Follow all lab safety protocols when handling chemicals, including protective eye and skin wear and appropriate lab clothing.

Ammonium Reagents

Citrate Complexing Reagent (4L)

<ul>
	<li>Sodium Citrate 112g</li>
	<li>Sodium Hydroxide 4 g</li>
	<li>Nanopure Water 4L</li>
	<li>Brij 35 (30%) 20 ml</li>
</ul><h5>Partially fill a 4L Erlenmeyer flask with nanopure water. Add dry chemicals, stir until dissolved then bring to volume (4L) with nanopure water. Filter reagent then add 20 ml 30% Brij 35 (5 ml / L). This may be stored at room temperature or be refrigerated.</h5>

Alkaline Phenol (1L)

<ul>
	<li>Sodium Hydroxide (10N or 40% w/v) 80 ml</li>
	<li>Liquid Phenol (88%) 94 ml</li>
	<li>Nanopure Water 1 L</li>
</ul><h5>Partially fill a 1L volumetric flask with nanopure water. Place in ice bath and stir while slowly adding sodium hydroxide first, then liquid phenol. Dilute to volume (1 L) with nanopure water and filter. Store refrigerated in light resistant container.</h5>
NOTE: This reagent is hazardous waste! Any glassware, paper towels, gloves, filter paper, etc used/contaminated during this process must be treated or disposed of as hazardous waste.

Sodium Nitroferricyanide (1L)

<ul>
	<li>Sodium Nitroferricyanide 0.5 g</li>
	<li>Nanopure Water 1L</li>
</ul><h5>Partially fill a 1L volumetric flask with nanopure water. Carefully measure sodium nitroferricyanide and add to nanopure water. Dilute to volume (1L) with nanopure water and filter. Store refrigerated in light resistant container.</h5>
NOTE: This reagent is hazardous waste! Any glassware, paper towels, gloves, filter paper, etc used/contaminated during this process must be treated or disposed of as hazardous waste.

10N Sodium Hydroxide (1L)

<ul>
	<li>Sodium Hydroxide 400g</li>
	<li>Nanopure Water 1L</li>
</ul><h5>Partially fill a 1L volumetric flask with nanopure water and place in ice bath. <span class="caps">SLOWLY</span> add sodium hydroxide while stirring to dissolve. This produces an exothermic reaction. Allow solution to cool to room temperature and bring to volume (1L) with nanopure water.</h5>
NOTE: This is REALLY messy, nasty stuff to work with so my advice is to buy it already made up.

Nitrate/Nitrite Reagents

Ammonium Chloride EDTA Buffer (4L)

<ul>
	<li>Ammonium Chloride 340 g</li>
	<li><span class="caps">EDTA</span> 0.4 g</li>
	<li>10N Sodium Hydroxide 26+ ml</li>
	<li>Nanopure Water 4L</li>
	<li>Brij 35 (30%) 8ml</li>
</ul><h5>Partially fill a 4L Erlenmeyer flask with nanopure water. Add ammonium chloride and <span class="caps">EDTA</span> and stir until dissolved. Adjust buffer solution using 10 N sodium hydroxide (start with 26 ml and add from there as needed) to pH 8.50. Dilute to volume (4 L) with nanopure water and filter. Add 8 ml 30% Brij 35 (2 ml / L). Store refrigerated.</h5>
NOTE: Keep some of the buffer on hand that does not have Brij 35 added to it. The buffer without Brij is needed to rinse and store the cadmium reduction coil after use. Routinely 1L of the ammonium chloride EDTA buffer is set aside in a separate 1L bottle and 6 ml of Brij 35 is added to the other 3L. Brij can always be added previous to use if necessary but the cadmium coil should not be stored in buffer that has Brij in it.

Color Reagent (1L)

<ul>
	<li>Phosphoric Acid (85%) 100 ml</li>
	<li>Sulfanilamide 40 g</li>
	<li>N-1-Naphthylethylenediamine dihydrochloride 2g</li>
	<li>Nanopure Water 1 L</li>
</ul><h5>Partially fill a 1 L volumetric flask with nanopure water. On stir plate, add phosphoric acid then dry chemicals. Stir until dry chemicals are dissolved. This can take several hours of stirring. Bring to volume (1L) with nanopure water and filter.  Store refrigerated in light resistant container.</h5>

Cadmium Coil Activation/Recharge Reagents

(see page 17 of The Flow Solution Nitrate/Nitrite Methodology for procedure)

<ul>
	<li>Nanopure Water</li>
	<li>0.5 N Hydrochloric Acid</li>
	<li>2% Copper Sulfate</li>
	<li>Ammonium Chloride <span class="caps">EDTA</span> Buffer (no Brij 35)</li>
</ul><h4>0.5 N Hydrochloric Acid (1L)</h4>

<ul>
	<li>Hydrochloric Acid (conc.) 41.5 ml</li>
	<li>Nanopure Water 958.5 ml</li>
</ul><h5>Partially fill a 100 ml volumetric flask with nanopure water. While stirring (and in the hood), slowly add the hydrochloric acid. Bring to volume (1L) with nanopure water.</h5>

2% Copper Sulfate (1L)

<ul>
	<li>Copper Sulfate 20 g</li>
	<li>Nanopure Water 1L</li>
</ul><h5>Partially fill a 1L volumetric flask with nanopure water. Add copper sulfate and stir until dissolved. Bring to volume (1L) with nanopure water.</h5>

Super Cartridge Cleaning Solutions

If there are problems with contamination in the cartridges the following solutions may be used to clean the interior and related tubing. It is not necessary to disconnect plumbing to do this.

Nitrate/Nitrite Cartridge

<ul>
	<li>1 N Sodium Hydroxide</li>
	<li>1 N Hydrochloric Acid</li>
</ul><h4>Ammonium Cartridge</h4>

<ul>
	<li>1 N Sodium Hydroxide</li>
	<li>1 N Sulfuric Acid</li>
</ul><h4>1 N Sodium Hydroxide (500 ml)</h4>

<ul>
	<li>10 N Sodium Hydroxide 50 ml</li>
	<li>Nanopure Water 450 ml</li>
</ul><h5>Partially fill a 500 ml volumetric flask with nanopure water. While stirring (and in the hood), slowly add the sodium hydroxide. Bring to volume (500 ml) with nanopure water.</h5>

1 N Hydrochloric Acid (200 ml)

<ul>
	<li>Hydrochloric Acid (conc.) 16.6 ml</li>
	<li>Nanopure Water 183.4 ml</li>
</ul><h5>Partially fill a 200 ml volumetric flask with nanopure water. While stirring (and in the hood), slowly add the hydrochloric acid. Bring to volume (200 ml) with nanopure water.</h5>

Date modified: Tuesday, Oct 24 2023

Author:

Datatables

    we no longer use Brij and we buy stock solutions for standards.

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