I've read the messages on this thread and think I could add a few things.
When it comes to the "degree of purity" (chemical grade ) of a chemical substance there are different degrees of purity, signifying the amount of care taken to assure that the amount of contaminants is at a minimum.
The "grades of purity" in our case are .....
=====================================================================================
1. A.C.S. A chemical grade of highest purity and meets or exceeds purity standards set by American Chemical Society (ACS).
2. Reagent High purity generally equal to A.C.S. grade and suitable for use in many laboratory and analytical applications.
3. U.S.P. A chemical grade of sufficient purity to meet or exceed requirements of the United States Pharmacopeia (USP); acceptable for food, drug, or medicinal
use; may be used for most laboratory purposes.
4. N.F. A grade of sufficient purity to meet or exceed requirements of the United States National Formulary. (Since bought out and merged with the United States
Pharmacopeia, USP-NF.)
5. Lab A chemical grade of relatively high quality with exact levels of impurities unknown; usually pure enough for educational applications. Not pure enough to be offered for
food, drug, or medicinal use of any kind.
6. Purified Also called pure or practical grade, and indicates good quality chemicals meeting no official standard; can be used in most cases for educational applications. Not pure
enough to be offered for food, drug, or medicinal use of any kind.
7. Technical Good quality chemical grade used for commercial and industrial purposes. Not pure enough to be offered for food, drug, or medicinal use of any kind.
Source:
www.sciencecompany.com/Learn-Chemical-Grade-Definitions-from-Highest-to-Lowest-Purity-W53.aspx
=====================================================================================
2.
Want to really go crazy ? Check this !
Source:
www.reagents.com/products/reagents/grades.html
=====================================================================================
3.
Sigma -Aldrich uses for their chemicals the following "grades"
1. Analytical
2. Puriss ( Purum ?)
3. Puriss P.A. ( pro Analysi ) ( ACS Reagent ) Exceeds standard ACS specifications with additional trace metals analysis
4. Technical - Chemicals that do not have an established standard set for quality and impurity levels or for products where the purity is <90%. Variation in color and physical form is possible.
((
Purum, Puriss, and Technical are the 3 purity grades in the new common Fluka and Riedel-de Haën classification system.
The Puriss grade is >= 98.5% purity, Purum is >= 95.0% purity, and the Technical grade fluctuates, mostly >= 90% purity.
They offer only..... Puriss P.A. and..... Technical "grade"
Of course they also offer ... "stratospheric prices" !!!!!!
))) U$ 233.50 for 1 Kg.
Source:
www.sigmaaldrich.com/technical-service-home/product-portfolio.html
www.sigmaaldrich.com/catalog/search?interface=Product%20Name&term=Sodium+chlorite&N=0+&mode=mode%20matchpartialmax&focus=product&lang=en®ion=CA
=================================================================
80% solution ?
It depends on the kind of solution.... 28% w/w, or .....28% w/v. In the first case you should add 20 g of NaClO2 to 80 g of H2O. In the later case you should add 20g NaClO2 in a volumetric flask of 1000 ml capacity and add water in small quantities and mix until all NaClO2 granules are dissolved.
W = weight
V = volume
The final solution will NOT be a 28% NaClO2 solution since the initial substance was only 80% pure. ( the rest of 20 % is NaCl = kitchen salt )
Simplifying things here, since we are using very small quantities of the aqueous solution,, I assume that we talk here about "28% w/v" which is put in a volumetric flask 28 gr. of NaClO2 and bring to 100 ml with distilled water.
Now from what I've seen and inquired they only make a.... "technical grade" and a.... "puriss p.a.".
The puriss p.a. also has described the trace metal analysis list - see below.
Ag: ≤5 mg/kg ( Silver)
Al: ≤5 mg/kg (Aluminum)
Ba: ≤5 mg/kg (Barium )
Bi: ≤5 mg/kg ( Bismuth)
Ca: ≤50 mg/kg (Calcium)
Cd: ≤5 mg/kg (Cadmium)
Co: ≤5 mg/kg ( Cobalt)
Cr: ≤5 mg/kg ( Chromium)
Cu: ≤5 mg/kg (Copper )
Fe: ≤5 mg/kg (Iron)
K: ≤1000 mg/kg ( 1 gr / Kg or 1‰ or 1/1000 ) ( Potassium )
Li: ≤5 mg/kg ( Lithium)
Mg: ≤10 mg/kg (Magnesium)
Mn: ≤5 mg/kg ( Manganese)
Mo: ≤5 mg/kg ( Molybdenum)
Ni: ≤5 mg/kg ( Nickel )
Pb: ≤5 mg/kg (Plumb)
Sr: ≤5 mg/kg ( Strontium)
Tl: ≤5 mg/kg ( Thallium)
Zn: ≤5 mg/kg ( Zinc)
It's a "rich" list yet again at the dilution we are using,..... "the quantities are insignificant.
We are using only "drops" of the 28% solution, which ARE DILUTED AGAIN with juice, water, etc.( therefore "micrograms" of the said elements).
In the end in my conversation with Jim he stated that the "technical grade" is all right.
Hmmmm ! I guess it also depends who makes it ! Not China !
In my conversation with the companies I phoned about NaClO2, ........ I was amazed at the degree of ignorance, and practically ..."lack of care", as well as the ability to "make-up" things as the conversation progressed.
I do know a thing or two about " WORDS",.... and in the end they all agreed they didn't know the answers, yet... they refused to name the manufacturer which, at the last resort, is the only one who can provide the information.
Links where I found you can order NaClO2
**********
www.sigmaaldrich.com/catalog/search?interface=Product%20Name&term=Sodium+chlorite&N=0+&mode=mode%20matchpartialmax&focus=product&lang=en®ion=CA
**********
www.fishersci.ca/coupon.do?cid=41896&Page=&itemId=,AC223230025,AC223235000,AC223230050
www.fishersci.ca/support.aspx?id=56
**********
www.ic.gc.ca/app/ccc/srch/nvgt.do?lang=eng&prtl=1&sbPrtl=&estblmntNo=234567002900&profile=cmpltPrfl&profileId=201&app=sold
**********
tulucechemicals.com/categories.php?category=Sodium-Salts&parent_id=215
**********
www.alibaba.com/showroom/food-grade-sodium-chlorite.html ( Food Grade ???? I think Ali Baba is full of ...shit ! )
www.alibaba.com/countrysearch/CN/sodium-chlorite-naclo2-powder-80.html
The last one does sell min. 1 KG.
Hope this was helpful !