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Proficiency Testing in Chemical Fertilizer Analysis |
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| รหัสดีโอไอ | |
| Creator | Wannarut Chutibut |
| Title | Proficiency Testing in Chemical Fertilizer Analysis |
| Contributor | Jariya Wongtree, Thongchan Pimpet, Chadaporn Khongnam, Omara Hanjavanich, Jariya Prasatsrisupub, Sunantha Chompoonich |
| Publisher | Department of Agriculture |
| Publication Year | 2552 |
| Journal Title | Thai Agricultural Research Journal |
| Journal Vol. | 27 |
| Journal No. | 1 |
| Page no. | 43-54 |
| Keyword | proficiency, chemical fertilizer, reference material, homogeneity, Z-score, laboratory |
| URL Website | https://at.doa.go.th/journal |
| Website title | Thai Agricultural Research Journal |
| ISSN | 0125-8389 |
| Abstract | The proficiency of fertilizer testing was conducted at the Agricultural Chemistry group, Agricultural Production Science Research during October, 2005- September, 2007. The objective of the studies was to test the proficiency fertilizer of analysis in both public (governmental) and privates laboratories and compatible utilization of standard of fertilizer analysis qualification of quality assurance of ISO/ IEC 17025 in Thailand. The study was separated into two parts namely the first one with two compound fertilizers: formula 0-52-34 and 12-60-0 (N-P2O5-K2 O), were prepared as the internal reference material (IRM) and statistically assessed the homogeneity, stability as well as establishing for as-signed value. Homogeneity of the IRM was determined by testing variance of one-way ANOVA including outlier, the assigned value of 25 kg of the fertilizer IRM was 0 51.94 ? 1.14- 35.40 ? 0.83 and 12.09 ? 0.33 60.52 ? 1.30 0 respectively. In the second part, the IRM samples were sent to the fertilizer analysis laboratory in Thailand. Afterward, results from 21 laboratory participants comprised of 13 public and 8 private laboratories were statistically compared by using Z-score. The study was found that 80% of laboratory participants that analyzed ammonium- nitrogen had the satisfactory results; 16% and 4% in questionable and unsatisfactory results, in respective. In addition, for the total phosphate analysis, 90% of laboratory participants had the satisfied results and equally 5% in questionable and unsatisfactory results. For the water soluble potash analysis, 53% of laboratory participants had the satisfied results; 21 and 26% in questionable and unsatisfied results in respective. Finally, these conclusions were directly sent to laboratory participants and also comprised with valuable recommendations. The laboratory participants that had questionable and unsatisfactory results had been collected and improved the quality of analysis results. Nowadays, all of these participants had been successfully received the satisfactory results. In addition to qualify internal quality assurance of fertilizer analysis. two kinds of reference materials were economically saving budget approximately 10 million baths. Furthermore, these materials had been distributed to 3 other fertilizer laboratories. |
