In the above example, each of the containers will measure the same concentration of H2, 1ppm (10 drops of H2Blue). But, these three containers DO NOT CONTAIN THE SAME AMOUNT OF DISSOLVED H2. This is because, as the volume of water is halved, so too is the amount of dissolved H2, resulting in the SAME concentration and the same PPM reading in each container. From this example, it can be seen that the PPM measurement does not indicate how much H2 will be ingested when drinking the contents of each container. In order to know how much H2 will be ingested, the PPM measurement obtained from the test sample must be referenced to 1 liter. This means that we must calculate the equivalent density of each one if the same amount of H2 was dissolved in 1 liter. For example, glass #2, which measures 1ppm (in a 1/2 liter), in fact has an equivalent density of 0.5ppm (1/2mg H2 in 1 liter). Based on this principle, you will ingest the following amounts of H2 if you drink the entire contents of each of the above containers, all of which measure 1ppm (remember, 1ppm = 1mg dissolved in 1 Liter):
Glass #1 (volume = 1 Liter): 1 milligram of H2 will be ingested
Glass #2 (volume = 1/2 Liter): 1/2 milligram of H2 will be ingested
Glass #3 (volume = 1/4 Liter): 1/4 milligram of H2 will be ingested
Why Is PPM the same as mg/L?
As stated above, 1ppm = 1mg/L, but why is this true? Here is a detailed explanation:
We can think of 1ppm as "1 part of a substance (solute) dissolved in 1 million parts of water" (in our case the solute is hydrogen gas). So, what is a "part"? "Part" represents our unit of measure, the milligram (mg). Therefore, 1 milligram of H2 ("1 part") dissolved in 1 million milligrams of water ("1 million parts") is "one part per million". Since 1 liter of water weighs 1 million milligrams, PPM is equivalent to "mg per liter" (mg/L) for dilute concentrations.
Calculating the theoretical maximum amounts of H2 which can be produced and dissolved:
Knowing the number of milligrams of magnesium contained in the tablet (not the mass of the whole tablet, which can be ten times greater), we can calculate the theoretical maximum amount of H2 which can be produced. Then, knowing the maximum amount of H2 gas which can be produced, we can also approximate the levels of dissolved H2 (mg/L) and ingestible H2 (mg) which can be expected.
When calculating ingestible H2 levels, it is important to remember that only DISSOLVED H2 should be considered (regardless of how much H2 is produced). This is because in any system, a considerable amount of the H2 gas produced may never dissolve into the water, and instead escape into the surrounding air. A few variables come into play which have an impact on the percentage of H2 gas which ultimately dissolves into the water. For any given tablet size, these variables include:
* Whether the container is open or sealed: - pressure can help H2 dissolve better, although some tablets may perform better in an open container.
* Materials from which the container is constructed - less-porous materials hold H2 better
* The amount of time the tablet is permitted to dissolve - more time is generally (although not necessarily) better than less time.
* The temperature of the water - H2 gas will dissolve better in cold water, but the reaction will proceed slower
* The size of the magnesium particles- Smaller magnesium particles can result in smaller, "more dissolvable" H2 gas bubbles
*Agitation -Shaking or mixing the contents can encourage more H2 gas to dissolve
While a larger container may produce lower PPM readings, the amount of ingestible H2 will not necessarily be less.
Table 1 shows the maximum possible H2 production, the levels of measured PPM (mg/L) and ingestible H2 one can expect, based on two different magnesium tablets (A & B), two different volumes of water, 500 & 1000mL, and the anticipated percentage of H2 gas produced that ultimately dissolves into the water:
One final example will help to show why the PPM measurement by itself cannot tell us how much dissolved H2 a sample of water contains. Figure 3 shows the result of dissolving the same amount of H2 into three different volumes of water, 1 liter, ½ liter, and ¼ liter.
If the same amount of H2 gas is dissolved into half the volume of water, the measured PPM (H2 density) will double. But, this does not mean that the amount of dissolved H2 has doubled-the amount of H2has remained the same. Therefore, as we have seen in these examples, to know how much H2 will be consumed, the PPM measurement must be converted to mg/L.
What Is "PPM"?
PPM is an acronym for "Parts Per Million", a unit of measure that describes how much of one substance (called the "solute") is dissolved in water (called the "solvent"). This is a measurement of density (mass per unit volume). Although the term “PPM' is widely used, density is more accurately expressed in mg/L (milligrams per liter). Converting between these two units is simple: 1ppm = 1mg/L (for dilute concentrations). PPM is used to measure the concentrations of many substances in our daily life, including the amount of minerals in our drinking water or the oxygen levels in a fish aquarium.
A simple method for determining H2 amount:
If you want to use the PPM measurement to calculate the amount of dissolved H2 in any size container, here is a simple method: Multiply the measured PPM by the size of the container the sample was taken from (in liters). This will tell you how much H2 is contained within the container.
For Example: If you have a 500mL portable bottle (0.5L) which measures 2ppm, multiply: 0.5 x 2 = 1milligram. Therefore, if you drink the entire 500mL container, you will ingest 1mg of H2.
From Table 3 it can be seen that, as the dissolved H2 concentration falls below 0.5mg/L, the amount of water which must be consumed to deliver 2mg/day of ingested H2 becomes prohibitively high. Therefore, it is important to choose a device or technology which is capable of consistently delivering H2 water at or above approximately 1mg/L.
Interpreting the results of the PPM measurement for batch-type electric devices:
Because batch devices contain a fixed volume of water into which the H2 gas is introduced, they are, in terms of PPM interpretation, more like tablets, which also introduce H2 gas into a fixed volume of water. Because they produce H2 gas electrically, they are not restricted in the amount of H2 gas they can produce, and the total dissolved H2 levels are influenced by the same variables mentioned previously. To interpret the PPM results from batch-type devices, use Table 1 in the previous section.
Figure 2 shows 3 glasses, each of which contains the same amount of water, 1 liter, and also the same amounts of dissolved H2 as in Figure 1. As a result, in contrast to Figure 1, they will each now measure a different concentration of H2, 1ppm, 0.5ppm and 0.25ppm respectively. Just as in Figure 1, the three glasses in this example also do not contain the same amount of dissolved H2. And, because their densities are different, drinking the entire contents WILL NOT provide the same levels of ingested H2. In order to receive the same ingested amounts of H2, you will need to drink varying amounts of each as follows:
Glass #1: You must drink 1 liter of 1ppm water to ingest 1 milligram of H2
Glass #2: You must drink 2 liters of 0.5ppm water to ingest 1 milligram of H2
Glass #3: You must drink 4 liters of 0.25ppm water to ingest 1 milligram of H2
From this example, it can be seen that when the PPM reading is referenced to a volume of 1 liter (mg/L), the PPM reading DOES indicate how much H2 will be ingested when drinking 1 liter from each container.
How much H2 do I need?
Now that we understand PPM's and how to interpret them to tell us the amount of dissolved hydrogen gas contained within a particular volume, the question becomes,
"How much H2 do I need to ingest everyday"?
Scientists are asking the same question, and the answer is currently being researched. What we do know is that human studies show significant health benefits when participants consume hydrogen water with concentrations in the 1-3mg/L range. This gives us a "target" dosage of approximately 2mg/day. Therefore, if your water has a concentration of 1ppm (1mg/L), then by consuming two liters per day, you will ingest 2mg of H2 per day. Based upon the H2 concentration of your water, you can use Table 3 below to calculate the volume of water you should drink in order to ingest approximately 2mg of H2 per day.
How to use this table:
* Select the value in column 1 corresponding to the amount of magnesium in your tablet, usually found on the label (if using two tablets, double the results shown in columns 2, 5 & 6)
Note: Some tablet labels will indicate both the magnesium amounts (typically 50-80mg), as well as the weight of the tablet itself (typically 500-600mg). Be sure to use the magnesium weight, not the weight of the entire tablet.
* Column 2 shows the theoretical maximum amount of hydrogen gas which can be produced from the tablet (under ideal conditions), based on the magnesium mass, the reaction's stoichiometry and corresponding molecular weights.
* Select the value in column 3 corresponding to the volume of water into which the tablet is to be dissolved.
* Select the value in column 4 corresponding to the anticipated percentage of dissolved hydrogen. Values will vary depending on preparation method, but will typically be in the 25% to 75% range, depending on the technology being used.
* Column 5 will give the approximate mg/L you would expect to measure based upon the amount of magnesium in the tablet, container volume, and % of the produced H2 which actually dissolves into the water.
* Column 6 will give the approximate amount of H2 which will be ingested if one drinks the entire contents of the container as listed in column 3.
Example: One 50mg tablet is capable of producing 4.2mg of H2. If it is placed into a 500mL container, and we assume that 50% of the H2 gas produced will dissolve into the water (with the remaining 50% escaping into the air), then a concentration of approximately 4.2ppm will be measured, and approximately 2.1mg of H2 will be ingested when consuming the entire 500mL of water.
Hydrogen water produced using electric devices, such as alkaline ionizers and hydrogen infusion machines (HIM's):
Alkaline ionizers produce hydrogen water by reducing (adding electrons to) protons (H+ ions). The reduction reaction produces hydrogen gas molecules (H2) at the cathode:
The hydrogen gas bubbles then dissolve into the drinking water as it flows across the cathode(s).
Recently, a new type of hydrogen water device has emerged on the market, the hydrogen infusion machine (HIM). This type of device does not have a conventional "electrolytic cell", and instead produces H2 gas in a small hydrogen gas chamber (using a proton-exchange membrane, PEM). Then, rather than depending only on turbulent flow to dissolve the gas into the water, these devices mix the H2 gas into the drinking water stream using a special "dissolver chamber". Because these devices utilize special conductive membranes (PEM/SPE), they do not require that the source water contain any level of minerals (TDS or conductivity). While they are commonly referred to as "neutral-pH devices", the H2 water they produce will not necessarily be "neutral"; the final pH will be determined by the pH of the source water, which they typically do not alter.
Another type electric device now being marketed for producing H2 drinking water is the hydrogen pitcher, and its smaller counterpart, the portable hydrogen bottle. These are “batch” devices (not flow-through) which typically use PEM membrane technology (similar to the HIM) to produce neutral-pH H2 water. The levels of dissolved H2 will vary based on run times and water volumes. Because their run times are typically in the 5 to 30 minute range, they do not have the capacity to produce the same volume of water per minute as flow-through devices, although they are capable of producing H2 water with comparable PPM’s.
Interpreting the results of the PPM measurement for electric flow-through devices
Hydrogen tablets contain a finite amount of magnesium, and therefore can only produce a finite amount of hydrogen gas. They are also placed into a finite amount of water, which dictates (along with other variables) the PPM’s which can be measured. But, electric flow-through devices have no such limitation, and therefore essentially have an infinite supply of electrons for producing H2 gas (at least, as long as there is power available), as well as an infinite supply of water. As a consequence, we need not be concerned with the container size from which the 6mL test sample is taken when interpreting the PPM's measured using H2Blue. We know that, since electric flow-through devices can produce H2 water continuously, any test sample taken from the machine will likely be representative of its ability to provide any volume of H2 water at that concentration (within the design constraints of the machine). Therefore, to know how much H2 we will ingest, we only need to know two things:
1) The H2 concentration (mg/L) of the water it produces
2) The total volume of H2 water consumed (liters).
Table 2 shows the amount of H2 that will be ingested (in mg) when drinking 3 different volumes of hydrogen water, 250mL, 500mL and 1 liter at three different concentrations:
What does the PPM measurement tell me about my hydrogen water?
When using H2Blue to measure a sample of hydrogen water, each drop represents 0.1PPM of dissolved H2 gas. By adding together the total number of drops required to reach the titration endpoint (the point at which the next drop does not turn clear, but remains blue), the dissolved H2 level in PPM can be calculated (see Technical page). Because the results of each measurement done with H2Blue are expressed in PPM (or mg/L), it is important to understand what the PPM units mean. Instead of how many PPM's we have, what we really want to know is, "how much hydrogen will I ingest if I drink the entire contents of the container from which the test sample was taken"? How the results are interpreted depends, in part, upon how the hydrogen water was originally produced.
Hydrogen water produced using hydrogen tablets:
Hydrogen tablets produce hydrogen gas through the reaction between elemental magnesium (Mg) and water:
The production of hydrogen gas bubbles can easily be observed when placing a tablet in a clear container. If the tablet is placed into a sealed container, the pressure will rise as the volume of H2 gas produced increases. The elevated pressure can help the H2 to dissolve, although too much pressure may attenunate the reaction.
Distinguishing between "produced" and "dissolved" hydrogen gas:
Because each tablet contains a fixed amount of magnesium metal, usually in the range of 50 to 80 milligrams, the total amount of H2 gas which can be produced from each tablet is also fixed. Although the theoretical maximum amount of H2 gas which can be produced from one tablet (under ideal conditions) can be calculated based upon the amount of magnesium in the tablet (usually indicated on the label), not all of the H2 gas which can be produced will be produced because 1) some magnesium will react while still in the container due to exposure to environmental water vapor (humidity); 2) not all of the magnesium contained within the tablet will necessarily react when placed into water because of the formation of oxides on the magnesium particles (passivation).
Regardless of how much H2 is produced, all of it will not dissolve into the water. This is because a portion of the gas will escape into the air and be wasted. The percentage of H2 produced which actually dissolves into the water is typically in the 25% to 75% range. This percentage can be influenced (and often improved upon) by altering tablet variables such as magnesium particle size and acid content, and environmental variables such as temperature, reaction time, and pressure.
Calculating the amount of ingestible H2 based on the PPM measurement:
In order to convert the PPM measurement to the amount of ingestible dissolved H2 gas, the size of the container into which the tablet is placed (and from which the 6ml test sample is taken) must be taken into consideration. This is because it takes fewer milligrams of H2 to produce 1ppm in a smaller amount of water than it does in a larger volume of water. The graphic in Figure 1 illustrates this concept: