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Chain-of-Custody
It is essential to ensure sample
integrity from sample collection to data reporting. This includes the ability to trace
possession and handling of the samples from the time of collection through analysis and
final disposition. This process is referred to as chain-of-custody. At the Analytical
Laboratory chain-of-custody is managed as follows:
 | Sealed, labeled samples are
delivered to the laboratory by the client.
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| Upon receipt of the sample, a
chain-of-custody form is completed and signed by both the client's field technician and
the receiving Analytical Laboratory technician. The date, time, sample name and size
are recorded in duplicate; one copy is retained by the laboratory and the other is given
to the client.
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| In the laboratory, the sample
custodian inspects the sample condition, assigns a lab number and logs the sample into the
laboratory log book.
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| The sample custodian obtains
the sample analysis requirements and schedule from the customer or from ENVISTA (database
software), completes an analysis request sheet and gives it to the appropriate laboratory
technician.
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| The sample custodian is
responsible for ensuring that pH and TSS for daily samples are performed immediately.
This individual or a qualified designate is also responsible for measuring acidity
and alkalinity for all samples, making composite samples, cutting samples into appropriate
portions for different analysis purposes and preserving samples for storage.
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Sample Preservation
To minimize the potential for
volatilization or biodegradation between sampling and analysis, holding times are kept as
short as possible. If immediate analysis is not possible samples are stored at 4 ° C,
unless other storage requirements are indicated in the Standard Operating Procedures.
Chemical preservatives are added, as per the Standard Operation Procedure, when they will
not interfere with the analysis required.
Sample Containers
Most Analytical Laboratory Standard
Operating Procedures require sample containers made of polyethylene plastics. Exceptions
are samples which will be analyzed for oil & grease, dissolved oxygen and phosphate.
For these samples glass containers are required.
Due to the large volume of samples regularly
collected from a designated location, the laboratory offers a sample container recycling
program for its local industrial clients. Where possible, containers are recycled for use
at the designated location for an identified set of analytes. For anion analysis by ion
chromatography, containers are rinsed thoroughly with de-ionized water. For metals and
radionuclides analysis, containers are rinsed with 1:1 HNO3. To remove strong
residues of iron oxides, a concentrated HCl rinse is utilized. Following the appropriate
acid rinse, all sample containers are washed thoroughly with non-phosphate detergent, hot
water, running tap water and de-ionized water. Containers are air dried and capped for
future use.
Summary of Analytical Laboratory
Sampling and Handling Requirements
| Parameter |
Sample Type* |
Minimum Size
(ml) |
Preservation** |
Maximum
Storage Time Recommend/Regulatory |
| pH |
g |
100 |
analyze immediately |
2h / immediate |
| Acidity |
g |
100 |
refrigerate |
24 h/ 7 d |
| Alkalinity |
g |
100 |
refrigerate |
24 h/ 7 d |
| BOD5 |
g |
1000 |
refrigerate |
6 h / 48 h |
| Chloride |
g, c |
50 |
IC: none required |
28 d |
| 100 |
SIE: H2SO4
to pH<2 |
28 d |
| Fluoride |
g, c |
50 |
IC: none required |
28 d / 28 d |
| 100 |
SIE: H2SO4
to pH<2 |
28 d |
| Nitrate |
g, c |
50 |
IC: ASAP or
refrigerate |
48 h / 48 h |
| 100 |
UV: 2ml HCl(1N) to
pH<2 |
28 d |
| Nitrite |
g, c |
50 |
IC: ASAP or
refrigerate |
none / 48 h |
| 100 |
UV:
1ml HgCl2 or refrigerate |
7 d |
| Phosphorus |
g |
50 |
IC: filter &
refrigerate |
48 h |
| 500 |
UV: H2SO4
to pH<2 |
28 d |
| Sulfate |
g, c |
50 |
IC: filter &
refrigerate |
28 d /
28 d |
| 500 |
Grav: filter &
refrigerate |
| Ammonia |
g, c |
100 |
0.2ml H2SO4
to pH<2 |
7 d / 28 d |
| KjN |
g, c |
200 |
0.2ml H2SO4
to pH<2 |
7 d / 28 d |
| Metals, general |
g, c |
100 |
Add HNO3 to
pH<2 & filter |
6 months / 6 months |
| Hg |
g, c |
100 |
2 ml 20% K2Cr707
& refrigerate |
28 d / 28 d |
| Cu, Ni, Pb, Zn, Co, Cd, Ba or Al |
g, c |
500 |
Add HNO3 to
pH<2 |
6 months / 6 months |
| Conductivity |
g, c |
500 |
refrigerate |
28 d / 28 d |
| Oil & Grease |
g, c |
1000 |
Add HCl to pH<2
& refrigerate |
28 d / 28 d |
| Dissolved Oxygen |
g, c |
300 |
immediate |
0.5 h |
| SiO2 |
g, c |
200 |
refrigerate, do not
freeze |
28 d / 28 d |
| TSS |
g, c |
500 |
refrigerate |
7 d / 2-7 d |
| TDS |
g, c |
100 |
refrigerate |
7 d / 2-7 d |
| Turbidity |
g, c |
100 |
analyze same day or
store in dark refrigerator |
24 h / 48 h |
| Ra_226 |
g, c |
500 |
filter & add
HNO3 to pH<2 |
6 months / 6 months |
| Po_210/Pb_210 |
g, c |
1000 |
filter & add
HNO3 to pH<2 |
6 months / 6 months |
| Th(T) or isotopes |
g, c |
500 |
filter & add
HNO3 to pH<2 |
6 months / 6 months |
| U |
g, c |
100 |
filter & add
HNO3 to pH<2 |
28 d / 28 d |
| Gross Alpha/Beta |
g, c |
200 |
filter & add
HNO3 to pH<2 |
6 months / 6 months |
* g - grab sample; C - composite
sample ** IC - Ion Chromotography; SIE - Specific Ion Electrode; Grav -
Gravimetric; UV - Ultraviolet Spectrometry; d - day; h - hour
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