pH and ICP Techniques

1. pH and ICP Techniques Clemson

2. Scoop 2 checks • One blank • Double scoop 6 samples • Tag set with lab number, check, and blank positions pH quality control checks

3. Two QC check samples • Two samples at beginning, middle, and end of set • Cross Check electrodes #1 and #2 1 2 3 Quality control row

4. ck • Check both QC check values at beginning and within set • Check all double scooped samples at beginning, middle, and end of set • Buffer run - checks • Buffer run - blank (1:1, water:buffer) End of run verification

5. Friday • clean out electrode filling solution • fill with water • Ultrasonic cleaner • Store in buffer pH 7 for the weekend Maintenance

6. Monday • Take water out of electrode • Refill with KCl filling solution • Verify flow of KCl through filter • Refresh buffer solutions • Electrode (from Fisher) • Accumet rugged bulb pH combination electrode • 13-620-183A Maintenance – cont.

7. Check B data since April 1, 2010 • 115 continuous reads over a 2.5 month period • Rinse pH < 4.5 and > 7.0 • NAPT value 5.15 • Lab average 5.15 • stdev 0.036 pH Check values

8. Two checks within the set • One blank ICP quality control checks

9. Probe – Leeman Labs • Phone: 603-886-8400 • Part number 902-00017 • Check all tubing for cleanliness and kinks • Change pump winding tube when needed • Adjust pump winding clamp - look for smooth flow as sample travels though tube Sample entry

10. Aspirate yttrium stock solution • Look for the tip of the red bullet • Adjust nebulizer gas flow rate ARCOS TJA Nebulizer gas flow

11. Keep clean • Take apart to rinse out nebulizer and spray chamber parts • TJA – use cleaning wire • ARCOS • SeaSpray Nebulizer • Twister Spray Chamber • Cross Flow ARCOS ARCOS TJA Nebulizer and spray chamber

12. ARCOS – clean as needed – salt buildup • TJA – clean ~once a year TJA ARCOS Torch

13. Transient scan – run standard • Check to see when the peak intensities stabilize • Clemson – 35 second total flush • 25 seconds at 60 rpm • 10 seconds at 30 rpm 25 seconds P K Time (seconds) using pump speed of 60 rpm Setting the flush timeARCOS - Crossflow

14. 18 seconds 25 seconds Crossflow spray chamber Twister spray chamber Transient scan on ARCOS

15. Options for changing flush time • Spray chamber • Tubing length • Pump speed • Sample loop P – 100 ppm Ca – 100 ppm K – 100 ppm Na – 50 ppm 45 seconds 25 seconds Time in seconds using pump speed of 60 rpm Transient scan going to rinseARCOS - Crossflow

16. Run time scan • Check time for stability • Clemson soil method • pump speed 200 rpm • flush time 30 seconds Ca - 40 seconds Pump speed 175 rpm Setting the flush time - TJA

17. Look at several recommended lines • Clemson - Ca line – 317.933 for soil Ca – 396.847Saturated signal Ca – 315.887 Line selection – ARCOS

18. Set peak position • Select clean area for background subtraction • Look for uncontaminated blank Peak position Cu – 324.754 Blank correction blank Method development - ARCOS

19. Run profile when needed • On the AROCS - check intensity of P158.599 line • If significant UV intensity drop – clean window and/or lens to optics • Check new standard against old • Read reference sample at start, mid point, and end of run • Verify 2 check samples and blank within set Instrument profile and data verification