Search:     Advanced search

Inductively Coupled Plasma Spectroscopy Determination of Potassium, Sodium, Calcium, Magnesium, Aluminum and Phosphorous

Article ID: 115
Last updated: 10 Apr, 2012

October 2009

INDEX


Number Subject

01 Scope and Application
02 Summary of Method
03 Interference’s
04 Range
05 Apparatus and Equipment
06 Safety
07 Requirements
08 Reagents
09 Standards
10 Procedure
11 Quality Control
12 Washing Procedure for Glassware and Centrifuge Tubes
13 References

TABLES

1. Method Detection Limits


FIGURES

1. Sample ID Sheet
2. Sample ID File
3. Program Element File
4. Instrument Page
5. AutoSampler Page

Inductively Coupled Plasma Spectroscopy

1. SCOPE AND APPLICATION

 1.1 This method is applicable for the determination of K, Na, Mg, Ca, Al and P in sample matrices of water, 2% nitric acid, 0.5M HCl, and soil extract (See cation soil procedure).

2. SUMMARY OF METHOD

 Inductively Coupled Plasma (ICP) Spectroscopy utilizes a high energy plasma not only to dissociate the sample but excite and ionize the atoms for atomic and ionic emission. The light emitted is focused onto a diffraction grating via a slit and a mirror. As the grating rotates a different wavelength is focused onto a second mirror and the exit slit. The light is then directed to a photomultiplier tube where the signal is amplified to a measurable amount. A calibration curve is developed for each element plotting intensity versus concentration.

3. INTERFERENCES

 ICP was developed to eliminate interferences encountered using Atomic Absorption. However there are usually more than one wavelength associated with each element and some wavelengths from different elements can overlap and interfere. Therefore a profile must be developed for each line and background correction applied if necessary.

 4. RANGE

  K, Na, Ca, Mg, Al and P all have a working range up to 1000ppm.


5. APPARATUS AND EQUIPMENT

  5.1 Jobin Yvon Ultima II Spectrophotometer (instrument was upgraded to an Ultima)

  5.2 Jobin Yvon AS 421 autosampler

  5.3 PolyScience water recirculator

  5.4 LabCraft nitrogen generator

 

6. SAFETY

  6.1 Never look directly at the plasma.

  6.2 The exhaust must be on.

  6.3 The quartz tubes, alumina injector, spray chamber and centering ring are soaked in aqua regia once a month. This must be done under the hood.

  

7. REQUIREMENTS

  7.1 Gases

 Liquid Argon

 N2, produced from N2 generator using air from air compressor

  7.2 Water recirculator

 

8. REAGENTS

8.1 All calibrants and QC’s are made in the same matrix of the samples being analyzed. Trace metal acids are used when needed.

  8.2 1000ppm Yttrium for setting the nebulizer pressure is purchased from Fisher Scientific.

  8.3 ICP Instrument Check 1, cat# JYICP-QC1 purchased from Horiba, used to determine stability and LOD.

  8.4 Aqua regia – Using trace metal acids make up a 3 to 1 HCl HNO3 solution under the hood using caution.

  

9. STANDARDS AND CALIBRANTS

  9.1 Calibrant – ICP custom mix #Q-5067 purchased from NSI Solutions Inc

  9.2 QC calibration check -ICP custom mix #Q-5068 purchased from NSI Solutions Inc

  9.3 Quarterly QC – Certified samples purchased from Environmental Resource Associates cat#ERA530

   9.4 ICP Instrument Check 1, cat# JYICP-QC1 purchased from Horiba, used to determine stability and LOD

 

10. PROCEDURE

  10.1 Turn on the instrument and N2 generator and stabilize for 24 hours.

  10.2 After instrument stabilizes, turn on water recirculator and exhaust.

  10.3 Spectrometer Start Up

 a. Turn on computer.

 b. Open up ICP 5.4.2 program.

 c. In the Automatism screen, start plasma.

 d. Go to rinse icon and set rinse.

e. Go to instrument icon and then communication detail. Perform zero order and then reference check.

f. Make up 1 to 100 dilution using ICP Instrument Check 1 and run stability check and LOD.

 g. Create a sequence by:

 1. Select sequence icon

 2. Use drop down menu to select method.

 3. Under location of samples tab, select tray.

 4. Under sequence tab, insert peak search, auto attenuate and calibration.

 5. Insert samples and QCs.

 6. Save giving file name date of analysis, ddmmyy.

 h. Run sequence by selecting arrow in upper left hand corner.

   10.4 Shut down

 a. Once sequence is complete, go to automatism screen and stop plasma.

 b. Release tension on pump tubes.

 c. Close off argon.

 d. Turn off exhaust.

 e. Turn off water recirculator.

 f. If instrument will not be used for a week or more:

 1. Turn off instrument.

 2. Turn off N2 generator by shutting down air compressor at the breaker.

   10.5 Special Considerations

 The temperature of the room should be kept at 70°F.

  10.6 Maintenance

At least once per month soak the outer and inner quartz tubes, spray chamber, centering ring, and alumina injector tube in aqua regia overnight. After soaking, discard acid, flush with DI and soak for 1 hour in DI. Rinse again in DI and allow to dry before reassembling torch. The o-rings in the torch and spray chamber should be replaced at this time.


11. QUALITY CONTROL

  11.1 A three point( or more) calibration curve is generated at the start of the run.

  11.2 The calibration curve is checked using a certified standard.  An accuracy of ±10% and a precision of 2% or less is maintained.

  11.3 During the run the instrument recalibrates as dictated in the method.

  11.4 Quarterly checks on the instrument are made using Environmental Resource Associates and NSI Solutions Inc certified QCs.

 

12. WASHING PROCEDURE FOR GLASSWARE AND CENTRIFUGE TUBES

  12.1

 a. Wash in Joy dishwashing liquid.

 b. Rinse with tap water.

 c. Soak overnight with 5% HNO3.

 d. Rinse five times in deionized water.

 

13. REFERENCES

 

 13.1 How to Realize an Analysis in ICP with Version 5 Software, Jobin Yvon Horiba, Reference 31 088 494,February 2000.


Table 1 - PRECISION AND BIAS

 

2%HNO3

 K(mg/l)

 Na(mg/l)

 Ca(mg/l)

 Mg(mg/l)

P(mg/l)

1

0.21

0.21

0.23

0.26

0.29

2

0.23

0.21

0.23

0.25

0.24

3

0.22

0.22

0.23

0.25

0.25

4

0.21

0.22

0.24

0.25

0.25

5

0.22

0.21

0.24

0.25

0.26

6

0.23

0.22

0.24

0.25

0.25

7

0.23

0.22

0.23

0.24

0.24

8

0.23

0.23

0.24

0.25

0.26

9

0.22

0.21

0.23

0.25

0.23

10

0.22

0.21

0.23

0.25

0.26

avg

0.222

0.216

0.234

0.250

0.253

std

0.008

0.007

0.005

0.005

0.016

mdl

0.022

0.020

0.015

0.013

0.046

 

 

 

DI water

 K(mg/l)

 Na(mg/l)

 Ca(mg/l)

 Mg(mg/l)

1

0.256

0.253

0.264

0.245

2

0.240

0.253

0.267

0.245

3

0.235

0.249

0.296

0.245

4

0.243

0.247

0.262

0.245

5

0.247

0.250

0.266

0.243

6

0.236

0.246

0.301

0.245

7

0.241

0.247

0.269

0.243

8

0.253

0.245

0.258

0.244

9

0.242

0.246

0.270

0.244

10

0.241

0.250

0.261

0.246

avg

0.243

0.249

0.271

0.244

std

0.007

0.003

0.015

0.001

mdl

0.019

0.008

0.042

0.003

 

 

student t with nine degrees of freedom and a 99% confidence level = 2.821


Figure 1. – Sample ID Sheet

 

Samples_________________________________

Date__________________

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1-1______

_________________

1-12

_________________

1-23

_________________

1-34

_________________

 

 

 

 

 

 

 

 

 

 

1-2

_________________

1-13

_________________

1-24

_________________

1-35

_________________

 

 

 

 

 

 

 

 

 

 

1-3

_________________

1-14

_________________

1-25

_________________

1-36

_________________

 

 

 

 

 

 

 

 

 

 

1-4

_________________

1-15

_________________

1-26

_________________

1-37

_________________

 

 

 

 

 

 

 

 

 

 

1-5

_________________

1-16

_________________

1-27

_________________

1-38

_________________

 

 

 

 

 

 

 

 

 

 

1-6

_________________

1-17

_________________

1-28

_________________

1-39

_________________

 

 

 

 

 

 

 

 

 

 

1-7

_________________

1-18

_________________

1-29

_________________

1-40

_________________

 

 

 

 

 

 

 

 

 

 

1-8

_________________

1-19

_________________

1-30

_________________

1-41

_________________

 

 

 

 

 

 

 

 

 

 

1-9

_________________

1-20

_________________

1-31

_________________

1-42

_________________

 

 

 

 

 

 

 

 

 

 

1-10

_________________

1-21

_________________

1-32

_________________

1-43

_________________

 

 

 

 

 

 

 

 

 

 

1-11

_________________

1-22

_________________

1-33

_________________

1-44

_________________

 

 

 

 

 

 

 

 

 

 

2-1

_________________

2-12

_________________

2-23

_________________

2-34

_________________

 

 

 

 

 

 

 

 

 

 

2-2

_________________

2-13

_________________

2-24

_________________

2-35

_________________

 

 

 

 

 

 

 

 

 

 

2-3

_________________

2-14

_________________

2-25

_________________

2-36

_________________

 

 

 

 

 

 

 

 

 

 

2-4

_________________

2-15

_________________

2-26

_________________

2-37

_________________

 

 

 

 

 

 

 

 

 

 

 

 

2-10

_________________

2-21

_________________

2-32

_________________

2-43

_________________

 

 

 

 

 

 

 

 

 

 

2-11

_________________

2-22

_________________

2-33

_________________

2-44

_________________

 

 

 

 

 

 

 

 

 

 

3-1

_________________

3-12

_________________

3-23

_________________

3-34

_________________

 

 

 

 

 

 

 

 

 

 

3-2

_________________

3-13

_________________

3-24

_________________

3-35

_________________

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3-11

_________________

322

_________________

3-33

_________________

3-44

_________________

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Article ID: 115
Last updated: 10 Apr, 2012
Revision: 1
Views: 0
Prev   Next
Atomic Absorption Spectroscopy Determination of Potassium,...     Combustion Analysis of Water Samples for Dissolved Organic...