Introduction:
This study evaluated the effectiveness of the NovaWAVE microwave digestion system for the digestion of waste water samples.
Sample Type:
Waste water- Municipal waste water in house.QC sample.
• Sample volume: 5 ml
• 4 Replicates
Supplies and Reagents:
 |
1) NovaWAVE SA Model* * Manufactured by SCP SCIENCE |
Sample Preparation Procedure:
The waste water sample was measured in a graduated cylinder and transferred into a 75 ml quartz vessel. After adding 25 ml of DI water, 1 ml of HNO3 and 1 ml of 1:1 HCl:H2O, the sample was digested in the NovaWAVE following the instrument’s heating profile noted below. After cooling, samples were normalized to 50 ml with DI water.
NOVAWAVE Heating Program:
| Stage |
Ramp Time (Minutes) |
Pressure (PSI – Limit) |
Temperature (oC) |
Hold Time (Minutes) |
| 1 | 10 | 435 | 175 | 10 |
Recoveries:
| Element | Mass (amu) |
NovaWAVE (ppm) |
Std. Dev. (ppm) |
Known Values (ppm) |
Recovery (%) |
| Li | 7 | 0.026 | 0.004 | 0.029 | 90 |
| Na | 23 | 181 | 1 | 181 | 99 |
| Mg | 24 | 21.8 | 1.1 | 22.6 | 96 |
| Al | 27 | 1131 | 9 | 1183 | 96 |
| P | 31 | 0.124 | 0.007 | 0.115 | 108 |
| K | 39 | 1.4 | 0.3 | 1.34 | 104 |
| Ca | 43 | 3.9 | 0.2 | 3.9 | 100 |
| Ti | 48 | 3.21 | 0.03 | 3.12 | 103 |
| Cr | 52 | 8675 | 80 | 8769 | 99 |
| Mn | 55 | 6.5 | 0.2 | 6.8 | 96 |
| Fe | 57 | 7.15 | 1.3 | 6.79 | 105 |
| Cu | 63 | 50.6 | 0.5 | 56.1 | 90 |
| Zn | 68 | 20 | 0.7 | 21.9 | 91 |
| Sr | 88 | 0.08 | 0.009 | 0.075 | 107 |
| Sb | 121 | 49.8 | 2.3 | 55.2 | 90 |
| Ba | 138 | 0.035 | 0.008 | 0.033 | 106 |
| La | 139 | 0.56 | 0.03 | 0.51 | 110 |
| Tl | 205 | 4.4 | 0.1 | 4.3 | 102 |
| Bi | 209 | 16.8 | 1.8 | 16.8 | 100 |
Conclusion:
For determination of trace metals in waste water, the Ministry of Environment of Quebec sets the acceptable range of recoveries at 15%. All recoveries are within this range. Therefore, the NOVAWAVE system is suitable for waste water digestion.
References:
Certificate of Analysis SC9261560 from SCP SCIENCE
Certificate of Analysis NIST CRM 1059c
USCPSC-CH-E1001-08 method
By:
René-Viet Nguyen, Ph.D, P. Chem.
Application Chemist
