1.0 OBJECTIVE
1.1 To define a procedure for Expression of Analytical Results.
2.0 SCOPE
2.1 This procedure is applicable for the Expression of Analytical Results.
3.0 RESPONSIBILITY
3.1 QC-Microbiologist
3.2 QC- Chemist
3.3 QC- Head
4.0 ACCOUNTABILITY
4.1 In Charge – Quality Assurance
5.0 PROCEDURE
5.1 A result can be
reported as a percentage, part per thousand (ppt), part per million (ppm), part
per billion (ppb), etc.. Solutes can be
solids , liquids, or gases. The concentration can be expressed as weight solute
per weight sample (w/w), weight solute per volume solution (w/v), or volume
solute per volume solution (v/v).
5.2 For Solid
Solutes
% (w/w) = [weight solute
(g)/weight sample (g)] x 100
ppt (w/w) = [weight solute
(g)/weight sample (g)] x 1000
ppm (w/w) = [weight solute
(g)/weight sample (g)] x 106
ppb (w/w) = [weight solute
(g)/weight sample (g)] x 109
A ppm can be
represented by several terms like the one above, (mg solute/kg sample), ( g
solute/106g sample), etc..
5.3 If the solute
is dissolved in solution we have
% (w/v) = [weight solute
(g)/volume sample (mL)] x 100
ppt (w/v) = [weight solute
(g)/volume sample (mL)] x 1000
ppm (w/v) = [weight solute
(g)/volume sample (mL)] x 106
ppb (w/v) = [weight solute
(g)/volume sample (mL)] x 109
Also a ppm
can be expressed as above or as (g solute/106 mL solution), (mg
solute/L solution), or (mg/mL),
etc..
5.4 For Liquid
Solutes
% (v/v) = [volume solute
(mL)/volume sample (mL)] x 100
ppt (v/v) = [volume solute
(mL)/volume sample (mL)] x 1000
ppm (v/v) = [volume solute (mL)/volume sample (mL)] x 106
ppb (v/v) = [volume solute (mL)/volume sample (mL)] x 109
A ppm can be expressed as
above or as (mL/L), (mL/103 L), etc..
Nil