Transcript Analyze-Immediately Parameters pH Analyze Immediately Within 15 minutes of collection: • pH • Residual Chlorine • Temperature • Chlorine Dioxide • Dissolved Oxygen (probe) • Sulfite note sample collection.

Analyze-Immediately Parameters
pH
Analyze Immediately
Within 15 minutes of collection:
• pH
• Residual Chlorine
• Temperature
• Chlorine Dioxide
• Dissolved Oxygen (probe)
• Sulfite
note sample collection & analysis times!!!
Topics covered today:
• pH
• Temperature
• Dissolved
Oxygen (DO)
• Residual
Chlorine (TRC
or CPO)….
pH: what we will cover….
• Significance of pH.
(data quality)
• Points to Remember.
• Lab Chemicals.
• Good Lab Practices
(GLP).
• Review NJAC Regs.
as they pertain to the
recording & reporting
of data.
What exactly is pH???
• Negative log of Hydrogen
ion activity.
• pH above 7: alkaline or
basic.
• pH below 7: acidic.
• pH = 7 is considered
neutral.
• Di-ionized water saturated
with CO2 has pH = 5.65
Data Quality : “a piece a cake!”
• Properly working
instrument & clean
apparatus.
• Fresh buffers and
reagent rinse water.
• Hold times met.
• Correctly calibrated.
• Proper sample
handling.
• GLP
Data Quality: Calibration
Grab:
•
•
•
•
•
Daily, within 3 hrs. of sample analysis.
2 buffers, bracketed.
Mid-range check.
Record time, concentration and actual reading of each.
For initial calibration, reading must be +/- 0.05 of true
value.
• Recalibrate if difference is greater than +/- 0.2 (applies to
3 hr. check).
• Discard pH buffer aliquots after each use.
Data Quality: Calibration
Continuous:
• Weekly, unless otherwise stated by SA.
• Indirect Calibration - basically a grab (as close to electrode
as possible); measure within 15 minutes with lab pH
meter; compare readings of continuous monitor with lab
pH meter. Record info in logbook, sign & date.
• Direct Calibration (as in grab procedure). - accurate to 0.1,
per method (SM 4500-H B).
• Record time, concentration and actual reading of each.
• Discard pH buffer aliquots after each use.
Make sure…….
• Grab pH: meter in good
working order (field or
hand-held models vs.lab
or bench-top models).
• Continuous monitor: keep
probe clean.
• Calibrate as per method.
• Maintain calibration &
sample collection log.
• Maintain field data
notebook.
Make Sure (continued)• Discard buffers
IMMEDIATELY
following use - DO NOT
re-use!
• Discard expired buffers!
• Electrode is OK - not
damaged.
• Stir or swish sample
during measurement.
• Record time of analysis.
Make Sure (continued)• Meters must have
accuracy of +/- 0.05
and +/- 0.05 resolution
• ...since pH is
temperature-dependent
• Must be temperaturecompensated…
• or use stand-alone
thermometer…
Lab Chemicals…...
• FRESH buffers!
(purchase ready-made
or make yourself).
• Reagent water.
• Electrode filling
solution (if necessary).
Hold Times
• Pertains to grab pH
and indirect
calibration for
continuous
measurement.
• 0 - 15 minutes - note
time of collection &
time of analysis!
Good Lab Practices (GLP)
• Data signed, initialed
& dated.
• Instrument ID &
serial number
• NO pencil!
• NO white-out!
• Single-line, date &
initial all errors.
Analyze-Immediately parameters
Records
• NJAC 7:18-8.5 - This section pertains specifically
to Analyze-Immediately parameters…
• GENERAL: retain raw data records, quality
control data records, chain-of-custody forms,
laboratory reports…
• Storage of data - data must be filed & maintained
in an accessible location on lab premises for 1
year after analysis date…
• Long-term storage: records of analysis must be
stored for 5 years after analysis date.
Retain as Records of Analysis
• Assigned lab ID # or other form of ID
• date & time of analysis
• name & signature of person(s) who collected
sample
• name & signature of person(s) who analyzed
sample
• type of analysis performed & DSAM* used
(*DSAM=Dept. Sanctioned Analytical Method)
• results of analysis & raw data generated from
analysis
Reporting Results
• Certified environmental lab name & NJ lab ID
number
• date, time & location of sample collection and
sample analysis
• type of analysis performed and analytical method
employed
• results from analysis
• name & signature of environmental lab manager
or designee per NJ regulations (NJAC 7:182.11(a)1iii)
Summary
• Don’t underestimate
the importance of pH.
• Adhere to NJAC
Regulations and
approved method.
• Document-documentdocument!!!