What
Is pH And ORP?
Potential
Of Hydrogen (pH)
The
Simple Definition
pH is a logarithmic measure of hydrogen ion concentration, originally
defined by Danish biochemist Søren Peter Lauritz Sørensen
in 1909,
pH
= -log[H+]
where
log is a base-10 logarithm and [H+] is the concentration of hydrogen
ions in moles per liter of solution. According to the Compact Oxford
English Dictionary, the "p" stands for the German word for
"power", potenz, so pH is an abbreviation for "power
of hydrogen".
The pH
scale was defined because the enormous range of hydrogen ion concentrations
found in aqueous solutions make using H+ molarity awkward. For example,
in a typical acid-base titration, [H+] may vary from about 0.01 M
to 0.0000000000001 M. It is easier to write "the pH varies from
2 to 13".
The hydrogen
ion concentration in pure water around room temperature is about 1.0
× 10-7 M. A pH of 7 is considered "neutral", because
the concentration of hydrogen ions is exactly equal to the concentration
of hydroxide (OH-) ions produced by dissociation of the water. Increasing
the concentration of hydrogen ions above 1.0 × 10-7 M produces
a solution with a pH of less than 7, and the solution is considered
"acidic". Decreasing the concentration below 1.0 ×
10-7 M produces a solution with a pH above 7, and the solution is
considered "alkaline" or "basic".
pH is
often used to compare solution acidities. For example, a solution
of pH 1 is said to be 10 times as acidic as a solution of pH 2, because
the hydrogen ion concentration at pH 1 is ten times the hydrogen ion
concentration at pH 2. This is correct as long as the solutions being
compared both use the same solvent. You can't use pH to compare the
acidities in different solvents because the neutral pH is different
for each solvent. For example, the concentration of hydrogen ions
in pure ethanol is about 1.58 × 10-10 M, so ethanol is neutral
at pH 9.8. A solution with a pH of 8 would be considered acidic in
ethanol, but basic in water!
What
does drinking high pH water do to our health?
Among
the people who question the validity of alkaline water, the biggest
question is, "What happens to the alkaline water once it reaches
the stomach, which is highly acidic?" People who have some knowledge
of the human body, including medical doctors, ask this question. Let
me answer that question once and for all to erase any doubts about
the health benefits of alkaline water.
In order
to digest food and kill the kinds of bacteria and viruses that come
with the food, the inside of our stomach is acidic. The stomach pH
value is maintained at around 4. When we eat food and drink water,
especially alkaline water, the pH value inside the stomach goes up.
When this happens, there is a feedback mechanism in our stomach to
detect this and commands the stomach wall to secrete more hydrochloric
acid into the stomach to bring the pH value back to 4. So the stomach
becomes acidic again. When we drink more alkaline water, more hydrochloric
acid is secreted to maintain the stomach pH value. It seems like a
losing battle.
However,
when you understand how the stomach wall makes hydrochloric acid,
your concerns will disappear. A pathologist friend of mine gave me
the following explanation. There is no hydrochloric acid pouch in
our body. If there were, it would burn a hole in our body. The cells
in our stomach wall must produce it on an instantly-as-needed basis.
The ingredients in the stomach cell that make hydrochloric acid (HCl)
are carbon dioxide (CO2), water (H2O), and sodium chloride (NaCl)
or potassium chloride (KCl).
NaCl
+ H2O + CO2 = HCl + NaHCO3, or
KCl + H2O + CO2 = HCl + KHCO3
As we
can see, the byproduct of making hydrochloric acid is sodium bicarbonate
(NaHCO3) or potassium bicarbonate (KHCO3), which goes into blood stream.
These bicarbonates are the alkaline buffers that neutralize excess
acids in the blood; they dissolve solid acid wastes into liquid form.
As they neutralize the solid acidic wastes, extra carbon dioxide is
released, which is discharged through the lungs. As our body gets
old, these alkaline buffers get low; this phenomenon is called acidosis.
This is a natural occurrence as our body accumulates more acidic waste
products. There is, therefore, a relationship between the aging process
and the accumulation of acids.
By looking
at the pH value of the stomach alone, it seems that alkaline water
never reaches the body. But when you look at the whole body, there
is a net gain of alkalinity as we drink alkaline water. Our body cells
are slightly alkaline. In order for them to produce acid, they must
also produce alkaline, and vice versa; just as a water ionizer cannot
produce alkaline water without producing acid water, since tap water
is almost neutral.
When
the stomach pH value gets higher than 4, the stomach knows what to
do to lower it. However, if the pH value goes below 4, for any reason,
the stomach doesn't know what to do. That's why we take Alka-Seltzer,
which is alkaline, to relieve acidic stomach gas pain. In this case,
hydrochloric acid is not produced by the stomach wall, therefore,
no alkaline buffer is being added to the blood stream.
Let me
give you another example of a body organ that produces acid in order
to produce alkaline. After the food in the stomach is digested, it
must come out to the small intestine. The food at this point is so
acidic that it will damage the intestine wall. In order to avoid this
problem, the pancreas makes alkaline juice (known as pancreatic juice).
This juice is sodium bicarbonate, and is mixed with the acidic food
coming out of the stomach. From the above formulae, in order to produce
bicarbonates, the pancreas must make hydrochloric acid, which goes
into our blood stream.
We experience
sleepiness after a big meal (not during the meal or while the food
is being digested in the stomach), when the digested food is coming
out of the stomach; that's the time when hydrochloric acid goes into
our blood. Hydrochloric acid is the main ingredient in antihistamines
that causes drowsiness.
Alkaline
or acid produced by the body must have an equal and opposite acid
or alkaline produced by the body; therefore, there is no net gain.
However, alkaline supplied from outside the body, like drinking alkaline
water, results in a net gain of alkalinity in our body.
How
do you measure pH?
There
are several ways to determine the pH of
a sample. In our Alkaline Shop we offer two main ways to measure
pH. The first, and most accurate, is to use a electronic pH
meter. You can take a look at our meters by visiting our shop
here.
The second,
and much more economical method, is to use pH paper - or, as we sell
in our shop, pH
Stix. These pH test strips are made specifically to test
saliva and urine, and are the most accurate and economical test strips
on the market.
[
back to top ]
Oxidation
Reduction Potential (ORP)
What
exactly is ORP?
Oxidation Reduction Potential (ORP) is a measurement (in mV) of the
tendency or the strength that indicates whether a solution is oxidizing
or reducing (= deoxidizing).
Any positive
number indicates that the solution is oxidizing; the higher, the more
oxidizing. The same theory applies on the negative side, just in the
opposite direction; the lower, the more deoxidizing. And of course,
any negative number indicates a reducing or deoxidizing tendency.
When chemists first used
the term in the late 18th Century, the word "oxidation"
meant, "to combine with oxygen." Back then, it was a pretty
radical concept. Until about 200 years ago, folks were really confused
about the nature of matter. It took some pretty brave chemists to
prove, for example, that fire did not involve the release of some
unknown, mysterious substance, but rather occurred when oxygen combined
rapidly with the stuff being burned.
We can see examples of
oxidation all the time in our daily lives. They occur at different
speeds. When we see a piece of iron rusting, or a slice of apple turning
brown, we are looking at examples of relatively slow oxidation. When
we look at a fire, we are witnessing an example of rapid oxidation.
We now know that oxidation involves an exchange of electrons between
two atoms. The atom that loses an electron in the process is said
to be "oxidized." The one that gains an electron is said
to be "reduced." In picking up that extra electron, it loses
the electrical energy that makes it "hungry" for more electrons.
We also know that matter
can be changed, but not destroyed. You can alter its structure, and
can increase or decrease the amount of energy it contains - but you
can't eliminate the basis building blocks that make things what they
are.
Chemicals like chlorine,
bromine, and ozone are all oxidizers. It is their ability to oxidize
- to "steal" electrons from other substances - that makes
them good water sanitizers, because in altering the chemical makeup
of unwanted plants and animals, they kill them. Then they "burn
up" the remains, leaving a few harmless chemicals as the by-product.
Of course, in the process
of oxidizing, all of these oxidizers are reduced - so they lose their
ability to further oxidize things. They may combine with other substances
in the water, or their electrical charge may simply be "used
up." To make sure that the chemical process continues to the
very end, you must have a high enough concentration of oxidizer in
the water to do the whole job.
But how much is "enough?"
That's where the term potential comes into play.
"Potential"
is a word that refers to ability rather than action. We hear it all
the time in sports. ("That rookie has a lot of potential - he
hasn't done anything yet, but we know that he has the ability to produce.)
Potential energy is energy
that is stored and ready to be put to work. It's not actually working,
but we know that the energy is there if and when we need it. Another
word for potential might be pressure. Blow up a balloon, and there
is air pressure inside. As long as we keep the end tightly closed,
the pressure remains as potential energy. Release the end, and the
air inside rushes out, changing from potential (possible) energy to
kinetic (in motion) energy.
In electrical terms,
potential energy is measured in volts. Actual energy (current flow)
is measured in amps. When you put a voltmeter across the leads of
a battery, the reading you get is the difference in electrical pressure
- the potential - between the two poles. This pressure represents
the excess electrons present at one pole of the battery (caused, incidentally,
by a chemical reaction within the battery) ready to flow to the opposite
pole.
When we use the term
potential in describing ORP, we are actually talking about electrical
potential or voltage. We are reading the very tiny voltage generated
when a metal is placed in water in the presence of oxidizing and reducing
agents. These voltages give us an indication of the ability of the
oxidizers in the water to keep it free from contaminants.
What
does oxidation or reduction mean to our health?
The
consumption of oxidized foods and beverages tend to affect unfavorably
the chemical characteristics of the body fluids. Many foods and beverages
are highly oxidized and devoid of electrons.
Likewise,
the addition to one’s diet of negative hydrogen ions, which
are found to be especially high in organically grown vegetables, tends
to affect the body fluids in a favorable manner.
Naturally,
the ORP value varies quite widely between the foods and beverages.
Considering you want to avoid oxidizing your body internally as much
as possible, it is important to make a constant effort to eat and
drink of which ORP value is on the negative side. However, unfortunately,
the majority of what we eat and drink have positive ORP values, often
quite high.
Many
of you might be disappointed to know that some of the worst (the most
oxidizing) examples include alcohol beverages, soda, meat, which ironically
represent the most popular.
Also,
some interesting comparison can be made on the freshness of the food
at different stages of the product cycle.
For example,
a freshly squeezed orange juice shows an ORP of usually around -100mV
while most of the packaged orange juice show as high as +200mV.
How
do you measure ORP?
|
|
|
An ORP
probe is really a millivolt meter, measuring the voltage
across a circuit formed by a reference electrode constructed
of silver wire (in effect, the negative pole of the circuit),
and a measuring electrode constructed of a platinum band (the
positive pole), with the pool water in between.
The reference
electrode, usually made of silver, is surrounded by salt (electrolyte)
solution that produces another tiny voltage. But the voltage
produced by the reference electrode is constant and stable,
so it forms a reference against which the voltage generated
by the platinum measuring electrode and the oxidizers in the
water may be compared.
The difference
in voltage between the two electrodes is what is actually
measured by the meter. Modern ORP electrodes are almost always
combination electrodes, that is both electrodes are housed
in one body - so it appears that it is just one "probe."
Incidentally,
the meter circuitry itself must have very high impedance (resistance)
in order to measure the very tiny voltages generated by the
circuit.
|
What
is the typical ORP value of drinking water from a Water Ionizer?
While the actual ORP varies depending on the source water,
it is generally anywhere between -200mV and -500mV. Anything below
-550mV is considered too strong for human body to take internally,
and therefore not recommended for drinking.
