Organoleptic ID testing
This is usually the first step in the identification of herb samples coming into
the Quality Assurance testing area. This analysis includes testing with the senses
(checking the taste, odor, color and appearance of the raw herb material). Since
herbs are natural products, their characteristics may vary. However, they must fall
within a specified range.
Microscopy
A microscopic evaluation is performed on incoming herb samples to validate exactly
which plant parts the sample contains (roots, leaves, fruit, bark), and to look
for any foreign matter such as insect parts. This test involves the preparation
of a slide of each herb powder. By analyzing the cell structure of the sample under
the microscope, we can confirm the plant species and cell type (part of plant),
and see possible contamination.
Thin Layer Chromatography (TLC)
TLC is a reliable analytical technique that allows us to identify herbs and measure
their quality. Different components of an herb extract are separated from each other
using adsorption and capillary action. An extract is spotted onto a plate, and the
intensity of the spots represents the concentration of each component in the extract.
Trained personnel can identify the components by color and identify colorless substances
using a special detecting spray or ultraviolet light.
The TLC test allows us to “fingerprint” the herb sample and compare it to a library
of known standards. By using the TLC test in combination with the FTIR test (below),
NSP can be assured that the key components in a particular herb are present in the
sample. NSP occasionally uses TLC to do comparison testing. We test NSP products
against similar products made by competitors to ensure that the NSP products’ potency
and purity are greater than that of our competitors’ products.
Infrared Spectroscopy (FTIR)
It's official name is Fourier Transform Infrared Spectroscopy. The FTIR herb test
validates the authenticity and purity of an herb sample. A beam of infrared light
is passed through a sample of the herb. As the beam shines on the sample, the sample
absorbs energy from the beam at certain frequencies. If we chart the frequencies
at which the sample absorbs energy, we get the absorption spectrum of the herb.
No two herbs have the exact same absorption spectrum, so by comparing these charts
to existing charts, we can positively identify the herb.
This test is critical because some herbs look, smell and taste exactly alike, but
one may cost 25 times more than another. Without FTIR testing, there may be the
temptation to dilute the more expensive herb material with inexpensive “fillers.”
For example, golden seal plants have been over-harvested in recent years. As a result,
the supply is limited and the raw herb is very expensive. Some may be tempted to
dilute their golden seal with barberry, which has a similar chemical composition.
The FTIR test makes it impossible to get away with this.
This test also measures the level of the key components in herb samples so we can
maintain consistent levels of potency from one batch of product to the next.
Note the difference between absorption spectra from samples of golden seal and barberry:
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Golden Seal |
Barberry |
High Performance Liquid Chromatography (HPLC)
This extremely sensitive, computerized tool allows us to analyze the ingredients
in a mixture. We place a dissolved sample of a mixture in the autosampler unit and
pump it through the analytical column. The mixture separates into different vitamin
(or herb) components, and the highly sensitive detector measures the amount of each
component in the mixture down to parts per million. By analyzing printed HPLC plots,
we can verify proper ingredient ratios. We also use HPLC to examine the purity and
potency of raw materials. For example, we use liquid chromatography to measure the
parthenolide content in feverfew and the ephedra content in Chinese ephedra.
The figures below show plots for SynerPro® Multiple Vitamins & Minerals, and for
Chinese Fen-Chi™.
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SynerPro Multiple Vitamins & Minerals |
Chinese Fen-Chi |