EQUIPMENT

1. Perkin-Elmer Model 4100 ZL Atomic Absorption Spectrophotometer.
2. Perkin-0Elmer AS-71 Autosampler.
3. Lead electrodeless discharge lamp.
4. EDL power supply.
5. Pyrolytically coated, platform graphite tubes.
6. 2 mL sample cups.

INSTRUMENT PARAMETERS

1	Wavelength	283.3 nm
2	Slit Width	0.7 nm
3	Slit Height	LOW
4	Signal Type	Zeeman AA
5	Signal Measurement	Peak Area
6	Read Time	5 seconds
7	Read Delay	0 seconds
8	BOC Time	2 seconds
9	Sample Volume	20 micro L
10	Modifier Volume	10 micro L

FURNACE PARAMETERS

STEP	TEMP (C)	RAMP Time (sec)	HOLD Time (sec)	INT. FLOW
1	110	10	25	250
2	130	10	35	250
3	700	5	30	250
4	1600	0	5	0
5	2400	1	2	250

GAS

1. Argon 99.99%

STANDARDS

1. Stock Solutions:
   1. 1000 ppm Lead: Use certified, NIST traceable Plasma Grade Standard.
   2. 10 ppm Lead: Pipet 1 mL of 1000 ppm lead standard into a 100 mL volumetric flask. Dilute to volume with deionized water and mix well.
   3. 1 ppm Lead: Pipet 10 mL of 10 ppm lead standard into a 100 mL volumetric flask. Dilute to volume with deionized water and mix well.
2. Instrument Calibration Standards:
   1. Pipet the designated volumes of 1 ppm lead stock solution into 100 mL volumetric flasks. Dilute to volume with deionized water and mix well.

      Standard #	Stock Solution mL	Final Concentration ppb
      1	1	10
      2	3	30
      3	5	50

MATRIX MODIFIER REAGENTS

1. Palladium Nitrate: Pd(NO₃)₂
2. Magnesium Nitrate: Mg(NO₃)₂.6H₂O

MATRIX MODIFIER PREPARATION

1. Weigh 0.1083 g palladium nitrate into a 100 mL amber volumetric flask.
2. Add 0.0518 g magnesium nitrate to the 100 mL volumetric flask.
3. Dissolve and dilute to volume with deionized water and mix well. Store in a dark place.

AUTOSAMPLER LOADING

1. Load the autosampler tray in the following manner:

   Positions 1-34	client samples
   Position 35	matrix modifier
   Position 36	deionized water
   Position 37	10 ppb lead standard
   Position 38	30 ppb lead standard
   Position 39	50 ppb lead standard
   Position 40	quality control sample

PROCEDURE

1. Turn on argon, EDL power supply, AA unit, Computer, and Printer and install the lead electrodes discharge lamp
2. Set the EDL power supply current to 10 watts. If the lead lamp does not light, remove it from the instrument and light it using the UV starter source and set the current to 10 watts. Do not look directly at the lighted part of the lamp since it produces intense UV light. Allow the lamp to warmup for 10 minutes and adjust the current to 10 watts if necessary.
3. Using the mouse, double click on the "AA_INST.EXE" folder. Wait until the 2 bottom icons (4100 and THGA) highlight.
4. Click on the "PERFECT" icon.
5. Click on the "ELEMENT FILE" icon.
6. Scroll down to and click on "WATER_PB.GEL"
7. Click on "OK" - "Instrument is busy please wait" message will appear.
8. Click on "DATA FILE"
9. Click on "PB.DAT"
10. Click on "OK"
11. Click on "Completely Overwrite data file"
12. Click on "OK"
13. Click on "OK" again.
14. Click on "ID/WT FILE"
15. Scroll down to and click on "PB_H2O.IDW"
16. Click on "OK"
17. Put the cursor on "WINDOWS"
18. Go to and click on "ID/WEIGHT"
    1. Beginning at position 1, enter the sample identification for the samples being analyzed.
    2. If the sample has been diluted, enter the dilution factor in the "DILUTION" column.
    3. The "WEIGHT" column will always be 1 for water samples.
19. Click on the "bow tie" symbol.
20. Lamp stabilization check.
    1. Put the cursor on "WINDOWS"
    2. Go to and click on "CONTINUOUS GRAPHICS"
    3. Press "F2" and check to see if the lamp has stabilized.
    4. If the lamp is stable, press "F3"
21. Click on the "bow tie" symbol.
22. Click on "CALIBRATE" - calibration and analysis of the samples will begin.
23. Monitor furnace operation, calibration, and display peaks.
    1. Click on "FURNACE CONTROL"
    2. Put the cursor on "WINDOWS"
    3. Go to and click on "DISPLAY CALIBRATION"
    4. Click on "DISPLAY PEAKS"

QUALITY CONTROL

1. If the r value for the calibration curve is less then .990, remake the standards and recalibrate.
2. Analyze the quality control sample before and after the analysis of client samples. Values for both analysis must be within the control limits established by the supplier of this sample.

REFERENCES

1. Fishman, M. J. And L. C. Friedman, (eds).1985. Lead, atomic absorption stectrometric, graphite furnace. in Methods for the Determination of Inorganic Substances in Water and Fluvial Sediments. Techniques of Water-Resources Investigations of the United States Geological Survey, Book 5, Chapter A 1, Pages 342-347.
2. American Society for Testing and Materials. 1984. Annual book of ASTM standards. Section 11, water: Philadelphia American Society for Testing and Materials, v. 11.01, p. 39.
3. Manning, D. C., and W. Slavin, 1983, The determination of trace elements in natural waters, using the stabilized temperature platform furnace. Applied Spectroscopy, v. 37, p. 1.