Lead Testing at DTSCs Environmental Chemistry Lab

Описание: http://www.dtsc.ca.gov/
http://www.dtsc.ca.gov/ECL/index.cfm

Script:
Graphic Open:
Locator: Berkeley, CA
NATS of Scientist at soil samples
VO:
Scientists at The Department of Toxic Substances Control’s Environmental Chemistry Lab in Berkeley identify and measure concentrations of toxic chemicals that may reside in air, water, soil, hazardous waste streams, and biological tissue.
NATS of Scientist:
We receive a variety of samples…
VO:
Lead testing is a common at DTSC’s Berkeley lab.
SOT of Ken Neely, DTSC Research Scientist:
When the sample is received we log its weight, its appearance, its container...chain of custody needs to be through that point.
VO:
Through a process called digestion, the soil has to be broken down into liquid form in order to be analyzed.
SOT of Ken Neely, DTSC Research Scientist:
We liberate it from whatever complex it might be in…in organic soil material and get it to dissolve into the acids
VO:
In order to isolate the lead in the sample, a meticulous process of mixing strong acids, heating and filtering is done.
SOT of Ken Neely, DTSC Research Scientist:
Once we have the solution then we use ICPOES// Inductively Coupled Plasma Optical Emissions Spectrometry// Basically, we’re looking at light.
VO:
The ICP, or…chewie…as it is affectionately referred to here at DTSCs Berkeley lab, measures the amount of light an element gives off when it’s exposed to the ICPs plasma torch.
NATS of Torch
SOT of Ken Neely, DTSC Research Scientist:
One of the coolest things about the ICP is that we’re burning Argon…which is a noble gas…it’s not flammable.
VO:
The plasma torch subjects samples to 10,000 Celsius - hotter than the surface of the sun.
SOT of Ken Neely, DTSC Research Scientist:
When you have an electric range and it heats up and it glows red…that red color is a mixture of all the different elements in the metal.// When you excite an element it’s going to emit very specific wavelengths of light…that’s why we look at the Sun we know what the Sun is composed of by which colors it’s putting off.
NATS of ICP
VO:
Control samples are analyzed first in order to give the ICP a reference point for the type of light it’s looking for.
SOT of Ken Neely, DTSC Research Scientist:
Once we have enough samples of known concentration we can generate an algorithm.// Then we take the unknown solution that we prepared by digesting the soil…we show that to the instrument and the INTENSITY of that light, plug that into the algorithm and you can back calculate the concentration.
VO:
The results show up on this screen giving scientists a measurement of the amount of lead in the sample tested.
SOT of Ken Neely, DTSC Research Scientist:
Lead has very specific colors that it emits when it’s excited.//We are actually counting the photons that are coming off the lead.

VO:
State of the art instrumentation like the ICP is how scientists measure not only for lead but many other toxics. It’s part of the labs mission to protect public health and the environment from adverse effects of chemicals.
SOT of Ken Neely, DTSC Research Scientist:
We don’t only test lead on it. We test 16 different metals. The ICP is a workhorse in our laboratory.
DTSC End graphic
TRT:
2:59