Prakonsentrasi Ion Cd(II) dalam Sampel Pupuk Nitrogen, Fosfor dan Kalium (NPK) Menggunakan Alumina Teraktivasi sebagai Material Pengisi Kolom

<p>Prakonsentrasi ion Cd(II) dalam sampel pupuk nitrogen, fosfor dan kalium (NPK) menggunakan alumina teraktivasi sebagai material pengisi kolom telah dilakukan. Alumina terlebih dahulu diaktivasi dengan NaOH pada pH 8 sebelum dimasukkan ke dalam kolom. Beberapa parameter penting dalam tahapan prakonsentrasi yang dapat meningkatkan kinerja analitik pengukuran telah ditentukan menggunakan instrumen spektrofotometer serapan atom (SSA). Hasil penelitian menunjukkan kondisi optimum tahapan prakonsentrasi ion Cd(II), adalah pada volume sampel 10 mL, volume HNO3 adalah 4 mL pada konsentrasi 0,5 M, dengan nilai kapasitas retensi adalah 1,4113 mg Cd(II)/g alumina. Kinerja analitik pengukuran metode sangat baik, ditunjukkan dengan nilai batas deteksi metode adalah 2,7997 μg/L. Presisi metode dinyatakan sebagai persentase koefisien variansi adalah 4,03%. Penggunaan alumina sebagai bahan pengisi kolom dapat meningkatkan signal sebesar 2,5 kali dibandingkan dengan pengukuran ion Cd(II) secara langsung. Akurasi metode ini sangat baik, dengan nilai persen perolehan kembali adalah 91,67 – 103,49%, menunjukkan bahwa matriks sampel tidak mempengaruhi hasil pengukuran, sehingga metode ini dapat digunakan untuk analisis ion Cd(II) dalam sampel pupuk NPK. Estimasi ketidakpastian metode ini juga telah dihitung dan ditunjukkan dengan nilai persen ketidakpastian adalah 14,16%.</p><p><strong>Preconcentration of Cd(II) Ion in Nitrogen, Phosphor, and Kalium (NPK) Fertilizer Sample Using Activated Alumina as a Column Filler Material</strong>. The research about preconcentration of Cd(II) in NPK fertilizer using activated alumina as a column filler material was done. The column used a filler material of alumina previously activated using NaOH at pH 8. Some important parameters in the preconcentration stage are able to increase the analytical performance, determined using atomic absorption spectrophotometer (AAS). The result of the research shows the optimum condition of preconcentration stage Cd(II) ion are volume of the sample was 10 mL, the volume of eluent HNO3 was 4 mL with a concentration of 0.5 M, with the retention of capacity value was 1.4113 mg Cd(II)/g alumina. The analytical performance of this method is good, shown with the limit of detection value was 2.7997 μg/L. The precision of this method was indicated by the percentage of the coefficient variance of 4.03%. Alumina used as a filler column can increase the signal up to 2.5 times for direct Cd(II) ions measurement. The accuracy of this method is excellent, with the recovery percentage value was 91.67 – 103.49%, indicating that the matrices of NPK fertilizer give no effect on the results of measurements, and this method was capable of analyzing Cd(II) ions in NPK fertilizer. The uncertainty of this method was estimated as the percentage of the uncertainty of 14.16%.</p>

Prakonsentrasi Ion Cd(II) dalam Sampel Pupuk Nitrogen, Fosfor dan Kalium (NPK) Menggunakan Alumina Teraktivasi sebagai Material Pengisi Kolom

<p>ABSTRAK. Prakonsentrasi ion Cd(II) dalam sampel pupuk nitrogen, fosfor dan kalium (NPK) menggunakan alumina teraktivasi sebagai material pengisi kolom telah dilakukan. Alumina terlebih dahulu diaktivasi dengan NaOH pada pH 8 sebelum dimasukkan ke dalam kolom. Beberapa parameter penting dalam tahapan prakonsentrasi yang dapat meningkatkan kinerja analitik pengukuran telah ditentukan menggunakan instrumen spektrofotometer serapan atom (SSA). Hasil penelitian menunjukkan kondisi optimum tahapan prakonsentrasi ion Cd(II), adalah pada volume sampel 10 mL, volume HNO3 adalah 4 mL pada konsentrasi 0,5 M, dengan nilai kapasitas retensi adalah 1,4113 mg Cd(II)/g alumina. Kinerja analitik pengukuran metode sangat baik, ditunjukkan dengan nilai batas deteksi metode adalah 2,7997 μg/L. Presisi metode dinyatakan sebagai persentase koefisien variansi adalah 4,03%. Penggunaan alumina sebagai bahan pengisi kolom dapat meningkatkan signal sebesar 2,5 kali dibandingkan dengan pengukuran ion Cd(II) secara langsung. Akurasi metode ini sangat baik, dengan nilai persen perolehan kembali adalah 91,67 – 103,49%, menunjukkan bahwa matriks sampel tidak mempengaruhi hasil pengukuran, sehingga metode ini dapat digunakan untuk analisis ion Cd(II) dalam sampel pupuk NPK. Estimasi ketidakpastian metode ini juga telah dihitung dan ditunjukkan dengan nilai persen ketidakpastian adalah 14,16%.</p><p>ABSTRACT. Preconcentration of Cd(II) Ion in Nitrogen, Phosphor, and Kalium (NPK) Fertilizer Sample Using Activated Alumina as a Column Filler Material. The research about preconcentration of Cd(II) in NPK fertilizer using activated alumina as a column filler material was done. The column used a filler material of alumina previously activated using NaOH at pH 8. Some important parameters in the preconcentration stage are able to increase the analytical performance, determined using atomic absorption spectrophotometer (AAS). The result of the research shows the optimum condition of preconcentration stage Cd(II) ion are volume of the sample was 10 mL, the volume of eluent HNO3 was 4 mL with a concentration of 0.5 M, with the retention of capacity value was 1.4113 mg Cd(II)/g alumina. The analytical performance of this method is good, shown with the limit of detection value was 2.7997 μg/L. The precision of this method was indicated by the percentage of the coefficient variance of 4.03%. Alumina used as a filler column can increase the signal up to 2.5 times for direct Cd(II) ions measurement. The accuracy of this method is excellent, with the recovery percentage value was 91.67 – 103.49%, indicating that the matrices of NPK fertilizer give no effect on the results of measurements, and this method was capable of analyzing Cd(II) ions in NPK fertilizer. The uncertainty of this method was estimated as the percentage of the uncertainty of 14.16%.</p>

Source of Cadmium (Cd) In Soils and Its Transfer to Rice and Vegetables: Karotia Union, Tangail

Cadmium is a trace element which is not essential for human being. High cadmium concentration in some rice samples in Bangladesh was reported than that of other countries. This study was carried out to find out the Cd concentration fertilizers, soils, rice and vegetables and along with other chemical properties of Karotia union, Tangail sadar upazila, Tangail. A total of 29 samples were collected among the 14 soils from 7 stations at 0-15 cm and 16-30 cm depth respectively, 5 vegetables, 5 rice and also 4 different countries TSP fertilizers from local market. The Cd concentration values of all soil samples were found between 0.97 to 1.73 mg/kg (0-15 cm) and 0.53 to 0.83 mg/kg (16-30 cm), respectively and the vegetable sample values were found between 0.053 mg/kg to 0.123 mg/kg (d.w.).The rice sample values were found between 0.05 mg/kg to 0.096 mg/kg (d.w.). The fertilizer sample values were found between 20.67 to 92.33 mg/kg. The soil pH values obtained 7.06 to 7.70 (0-15 cm) and 7.48 to 7.88 (16-30 cm) which indicated that the study area soils were neutral to moderately alkaline. The EC values of all soil samples were between 47.67 to 82.67dSm-1 (0-15cm) and 33.33 to 58.33dSm-1 (16-30 cm). The organic matter content of all soils ranged from 0.789 to 0.905% and 0.351 to 0.869% at (0-15 cm and 16-30 cm), respectively. The available sodium (Na) values of soils were found between 1.84 to 1.92 ppm (0-15 cm) and 1.83 to 1.90 ppm (16-30 cm), respectively. The available potassium values ranged from 1.81 to 1.96 ppm (0-15 cm) and 1.84 to 1.97 ppm (16-30cm), respectively. The available calcium values of all soil samples were 1.92 to 1.97 ppm (0-15 cm) and 1.91 to 1.96 ppm (16-30 cm), respectively.

Comparison of digestion methods to determine heavy metals in fertilizers

The lack of a standard method to regulate heavy metal determination in Brazilian fertilizers and the subsequent use of several digestion methods have produced variations in the results, hampering interpretation. Thus, the aim of this study was to compare the effectiveness of three digestion methods for determination of metals such as Cd, Ni, Pb, and Cr in fertilizers. Samples of 45 fertilizers marketed in northeastern Brazil were used. A fertilizer sample with heavy metal contents certified by the US National Institute of Standards and Technology (NIST) was used as control. The following fertilizers were tested: rock phosphate; organo-mineral fertilizer with rock phosphate; single superphosphate; triple superphosphate; mixed N-P-K fertilizer; and fertilizer with micronutrients. The substances were digested according to the method recommended by the Ministry for Agriculture, Livestock and Supply of Brazil (MAPA) and by the two methods 3051A and 3052 of the United States Environmental Protection Agency (USEPA). By the USEPA method 3052, higher portions of the less soluble metals such as Ni and Pb were recovered, indicating that the conventional digestion methods for fertilizers underestimate the total amount of these elements. The results of the USEPA method 3051A were very similar to those of the method currently used in Brazil (Brasil, 2006). The latter is preferable, in view of the lower cost requirement for acids, a shorter digestion period and greater reproducibility.

Generic Performance Tests for the Fertilizer Sample Preparation Laboratory

Good sample preparation is an essential first step to almost all laboratory analytical procedures. The procedures presented are intended to stimulate interest in generic methods for performance testing of various steps in fertilizer sample preparation, including initial reduction of unground sample, grinding, and mixing. Sample reduction quality is measured by 2 types of procedures, the first using 2 sizes of glass beads for a more theoretical approach, and the second using 2 common fertilizer materials for a more empirical method. Grinding performance is measured by recovery and carryover methods, followed by particle size and uniformity estimates of the ground material. Mixing after grinding is tested by measuring time-to-blend of a segregated mixture.

Evaluation of Current AOAC Fertilizer Sample Preparation Requirements

The official AOAC fertilizer sample preparation requires that all dry mixtures be ground to pass a U.S. No. 40 sieve. With current fertilizers and mechanical grinders, these criteria may no longer be appropriate. Blended fertilizers were ground and sieved, and the fractions were analyzed separately to show potential variability in results. In general, potassium was heavily concentrated in the smaller particles of the ground sample, whereas phosphorus tended to be concentrated in the coarser particles. A representative set of fertilizers was subjected to 7 grinding treatments designed to produce samples with a wide distribution of particle size. N, P, and K were determined in the samples by traditional methods. Analysis of the results demonstrated that precise, accurate results could be obtained from samples that did not technically meet current sample preparation requirements. The relationship between fineness of grind and size of the analytical sample portion was examined. With proper sample grinding, sample sizes of ≤20 mg could give representative results for nitrogen analysis, with precision equal to or better than traditional Kjeldahl analysis using 1 g samples. This is of particular interest, because various combustion instruments now becoming popular for nitrogen analysis are limited in sample size.

Determination of Water in Compound Fertilizers

A method is proposed for determining the water content of nitrogen-potassium-phosphorus compound fertilizers. The method combines drying with methanol extraction, with or without ultrasonic comminution of the fertilizer. The total moisture content of the sample is calculated as a sum of1 that found by drying and that determined by the extraction method (residual moisture). Two methods of methanol extraction were used: extraction of the uncomminuted fertilizer sample directly in the titration vessel, or extraction of the comminuted sample by ultrasonic vibration. Water contents determined by the proposed method ranged from 0.3 to 1.7%. Standard deviations for extraction without and with comminution were 0.015 and 0.018%, respectively. Moreover, ultrasonic comminution of fertilizer increased the amount of residual water extracted by about 20% compared with other methods.

Atomic Absorption Spectrophotometric Determination of Molybdenum in Fertilizers

Molybdenum is extracted into chloroform from fertilizer sample solutions at pH 1.6 as the 8-hydroxyquinolate. Atomic absorption in the premixed nitrous oxide-acetylene flame is used for determination. Methyl isoamyl ketone is added to the chloroform extract to improve the burning qualities. The method is sensitive and precise but appears to have a positive bias of about 5%.

Atomic Absorption Spectrophotometric Determination of Water-Soluble Boron in Fertilizers

Water-soluble boron is extracted into a mixlure of 2-ethyl-l,3-hexanediol and methyl isobutyl ketone for determination by atomic absorption spectrophotometry. The extraction procedure brings the fertilizer sample, water, and extraction solvent in contact simultaneously. The organic layer which contains the extracted boron is aspirated into the flame. There are no significant interferences from elements commonly found in fertilizers. The proposed method is fast and accurate for determining water-soluble boron in fertilizers.

Sampling Bulk Fertilizers

A sampling study was designed to investigate the sampling of bulk loads of semigranular, granular, pulverized, and blended fertilizers. The study was designed to obtain information on appropriate instruments and methods for sampling bulk fertilizers. An accurate fertilizer sample can be secured by passing a stream sampling cup through the entire flow of material at equally timespaced intervals during the loading of a truck; this "stream" sample is used as a reference point. The AOAC triers did not secure accurate samples of bulk loads. Two compartmented triers and t h e stream sampler were recommended as official sampling instruments. A concentric sampling pattern for taking bulk samples was recommended. Studies on bulk sampling will continue.