TDS is the measure of total dissolved solids in fresh water sources. It includes inorganics and organics that typically can pass through a 2 micron filter. Measurement occurs in reality via conductivity. Charged cations and anions are a source of this “conductivity”. There are benchtop meters as well as portable field versions of these meters …
Blending stock standards for your custom in-house internal standard takes a little time, but it is very economical provided you already have the stock standards available. Start by pre-rinsing all glassware/plasticware with either dilute nitric or hydrochloric acid (depending on which acid makes up your end matrix). Then, rinse 3X with high purity DI water. …
Blending elements for ICP, ICP-MS, ICP-OES standards Read More »
Work involving pH Buffer Calibration requires calibration standards that are dependable and accurate. Providing your equipment is maintained well, measuring pH should not be a chore. Be sure you routinely go through the meter checkout procedure for your meter (according to your manufacturer’s directions) and perform a check on your electrode. Electrode checks involve submerging …
The titration of carbonates (typically sodium carbonate) involves a weak base vs a strong acid (hydrochloric acid 0.1N). Color change results are quite subjective if you just use a simple methyl orange, as the color change is very gradual. A good alternative is mixed methyl orange-xylene cyanole FF. This alternative will give a sharper color …
You have probably noticed that some liquid concentrations are marked as a percentage while others are noted as a normality. They can, in theory, be identical concentrations at times. But more often than not, they serve very different purposes in a laboratory. Normality is a measure of concentration equal to the gram equivalent weight per …
While it may seem like a solution of 10% refers to only one concentration value, percentage could indicate different concentration values depending on the type: Volume-Volume (v/v), Weight-Volume (w/v), and Weight-Weight (w/w). The most common variant is volume-volume (v/v). In v/v solutions, the noted product makes up a percentage of the final solution as a …
Volume-Volume (v/v), Weight-Volume (w/v), and Weight-Weight (w/w) in Percent Solutions Read More »
