Determination of Nitrogen, Phosphorus, and Potassium Release Rates of Slow- and Controlled-Release Fertilizers: Single-Laboratory Validation, First Action 2015.15

2016 ◽  
Vol 99 (2) ◽  
pp. 353-359 ◽  
Author(s):  
Nancy Thiex
Keyword(s):  
Controlled Release ◽  
Nutrient Release ◽  
Official Method ◽  
Release Rates ◽  
Expert Review ◽  
Expert Review Panel ◽  
Phosphorus And Potassium ◽  
Single Laboratory ◽  
Controlled Release Fertilizers

Abstract A previously validated method for the determination of nitrogen release patterns of slow- and controlled-release fertilizers (SRFs and CRFs, respectively) was submitted to the Expert Review Panel (ERP) for Fertilizers for consideration of First Action Official MethodSM status. The ERP evaluated the single-laboratory validation results and recommended the method for First Action Official Method status and provided recommendations for achieving Final Action. The 180 day soil incubation-column leaching technique was demonstrated to be a robust and reliable method for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and the results were only slightly affected by variations in environmental factors such as microbial activity, soil moisture, temperature, and texture. The release of P and K were also studied, but at fewer replications than for N. Optimization experiments on the accelerated 74 h extraction method indicated that temperature was the only factor found to substantially influence nutrient-release rates from the materials studied, and an optimized extraction profile was established as follows: 2 h at 25°C, 2 h at 50°C, 20 h at 55°C, and 50 h at 60°C.

scholarly journals Determination of Chondroitin Sulfate Content in Raw Materials and Dietary Supplements by High-Performance Liquid Chromatography with UV Detection After Enzymatic Hydrolysis: Single-Laboratory Validation First Action 2015.11

2016 ◽  
Vol 99 (1) ◽  
pp. 53-54
Author(s):  
Sharon L Brunelle
Keyword(s):  
Chondroitin Sulfate ◽  
Dietary Supplements ◽  
High Performance ◽  
Raw Materials ◽  
Method Performance ◽  
Expert Review ◽  
Performance Requirements ◽  
Expert Review Panel ◽  
Single Laboratory

Abstract A previously validated method for determination of chondroitin sulfate in raw materials and dietary supplements was submitted to the AOAC Expert Review Panel (ERP) for Stakeholder Panel on Dietary Supplements Set 1 Ingredients (Anthocyanins, Chondroitin, and PDE5 Inhibitors) for consideration of First Action Official MethodsSM status. The ERP evaluated the single-laboratory validation results against AOAC Standard Method Performance Requirements 2014.009. With recoveries of 100.8–101.6% in raw materials and 105.4–105.8% in finished products and precision of 0.25–1.8% RSDr within-day and 1.6–4.72% RSDr overall, the ERP adopted the method for First Action Official Methods status and provided recommendations for achieving Final Action status.

scholarly journals Plant Growth and Leachate Electrical Conductivity and pH as Influenced by Controlled-release Fertilizer Blends and Coating Technologies

2017 ◽  
Vol 27 (5) ◽  
pp. 639-643 ◽  
Author(s):  
Carey Grable ◽  
Joshua Knight ◽  
Dewayne L. Ingram
Keyword(s):  
Trace Elements ◽  
Controlled Release ◽  
Polymer Coating ◽  
Ornamental Plants ◽  
Nutrient Release ◽  
Dry Weight ◽  
Polymer Coatings ◽  
Release Rates ◽  
Shoot Dry Weight ◽  
Controlled Release Fertilizers

Although controlled-release fertilizers (CRFs) have been used in container-grown ornamental plants for decades, new coating technologies and blends of fertilizers coated for specific release rates are being employed to customize fertility for specific environments and crops. A study was conducted in the transitional climate of Kentucky to determine the nutrient release rates of three controlled-release blends of 8- to 9-month release and growth response of ‘Double Play Pink’ japanese spirea (Spiraea japonica) and ‘Smaragd’ arbovitae (Thuja occidentalis). Fertilizer 1 (16N–3.5P–8.3K–1.8Mg + trace elements) and Fertilizer 2 (18N–3.1P–8.3K–1.8Mg + trace elements) were prototype blends with different experimental polymer coatings. Fertilizer 3 was a blend of 18N–2.2P–6.6K–1.1Ca–1.4Mg–5.8S + trace elements, which combined 100% resin-coated prills with a polymer coating. Fertilizer 4 was commercially available 15N–3.9P–10K–1.3Mg–6S + trace elements. Fertilizer 3 released its nutrients earlier in the 12-week study than the other three fertilizers and resulted in lower shoot dry weight in both species. The new polymer coating technologies show promise for delivering a predicted release rate and are appropriate for container production of these woody shrubs in Kentucky. An interesting side note of this experiment was that leachate pH measurements across treatments averaged 1.2 units lower for arbovitae (6.3) than for japanese spirea (7.5) at week 12. It was assumed that chemical and/or biological reactions at the root/substrate interface in arbovitae moderated pH increases over the study.

Determination and Confirmation of Parent and Total Ractopamine in Bovine, Swine, and Turkey Tissues by Liquid Chromatography with Tandem Mass Spectrometry: First Action 2011.23

2012 ◽  
Vol 95 (5) ◽  
pp. 1235-1255 ◽  
Author(s):  
Thomas J Burnett ◽  
John M Rodewald ◽  
Sharon L Brunelle ◽  
Mark Neeley ◽  
Michael Wallace ◽  
...  
Keyword(s):  
Internal Standard ◽  
Veterinary Drug ◽  
Review Panel ◽  
Validation Data ◽  
Expert Review ◽  
Maximum Residue Limits ◽  
Initial Extract ◽  
Expert Review Panel ◽  
Single Laboratory

Abstract A candidate method selected by the AOAC Expert Review Panel (ERP) for Ractopamine for determination and confirmation of parent and total ractopamine by LC/MS/MS was validated in a single laboratory for bovine, swine, and turkey tissues. The candidate method utilizes methanol extraction of the tissues, followed by an optional enzymatic hydrolysis for determination of total (parent plus conjugate) ractopamine. A mixed-mode cation exchange SPE cartridge is used to purify the initial extract before LC/MS/MS. Matrix-matched standards and a ractopamine-d6 internal standard are used for quantification of parent and total ractopamine in unknown samples. Validation data demonstrated that mean intertrial recoveries for ractopamine across all concentrations tested ranged from 79.7 to 102.2% for parent ractopamine and from 79.0 to 100.0% when a hydrolysis step was included. Intertrial repeatability precision ranged from 2.44 to 11.1% for parent ractopamine and 4.97 to 15.0% with hydrolysis. Estimated LOD values were below 0.1 ng/g and LOQ values were validated at 0.25x the maximum residue limits. The data satisfy the requirements of the AOAC Stakeholder Panel for Veterinary Drug Residue Methods for single laboratory validation studies. The method was awarded Official Methods of AnalysisSM First Action 2011.23 by the AOAC ERP on Veterinary Drug Residues.

Determination of Sodium Fluoroacetate in Dairy Powders by Liquid Chromatography–Tandem Mass Spectrometry: Single-Laboratory Validation, First Action 2015.02

2016 ◽  
Vol 99 (1) ◽  
pp. 242-251 ◽  
Author(s):  
Lauren M Fleury ◽  
Bryan G Scahill ◽  
Rilka Taskova
Keyword(s):  
Infant Formula ◽  
Intermediate Precision ◽  
Method Performance ◽  
Expert Review ◽  
Liquid Chromatography Tandem Mass ◽  
Expert Review Panel ◽  
Single Laboratory ◽  
Lc Tandem Ms ◽  
Dairy Powders

Abstract A single-laboratory validation (SLV) study was conducted for the determination of sodium fluoroacetate in dairy powders by LC-tandem MS (LC-MS/MS). Linearity of response was confirmed by analysis of samples fortified over the concentration range 0.10–100 μg/kg. The LOD was estimated to be 0.028 μg/kg (0.028 ppb) from the SD of the measured concentrations of infant formula samples fortified at 0.10 μg/kg. The corresponding LOQ calculates at 0.085 μg/kg (0.085 ppb), which ensures excellent reliability of quantification at the limit of reporting of 1.0 μg/kg (1 ppb). Repeatability and intermediate precision were estimated from the SD of the recovery of samples fortified at 0.075, 0.10, 0.20, 0.50, 1.0, and 10.0 μg/kg. The previously mentioned method performance values were established using a representative stage 2 (6–12 months) bovine infant formula, and the robustness of the method was tested by the analysis of 107 unique dairy powders and formulations fortified at 1.0 μg/kg. The data collected in this study satisfy the requirements of SLV studies established by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN), and the method was awarded First Action Official MethodSM status by the AOAC Expert Review Panel on SPIFAN Nutrient Methods (Contaminants) on March 17, 2015.

scholarly journals Nutrient Release from Controlled-release Fertilizers in Acid Substrate in a Greenhouse Environment: I. Leachate Electrical Conductivity, pH, and Nitrogen, Phosphorus, and Potassium Concentrations

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 780-787 ◽  
Author(s):  
Donald J. Merhaut ◽  
Eugene K. Blythe ◽  
Julie P. Newman ◽  
Joseph P. Albano
Keyword(s):  
Electrical Conductivity ◽  
Controlled Release ◽  
Nutrient Release ◽  
Low Fertility ◽  
Plant Production ◽  
Production Cycle ◽  
Permissible Levels ◽  
Phosphorus And Potassium ◽  
Acid Substrate ◽  
Controlled Release Fertilizers

Release characteristics of four types of controlled-release fertilizers (Osmocote, Nutricote, Polyon, and Multicote) were studied during a 47-week simulated plant production cycle. The 2.4-L containers containing a low-fertility, acid-based substrate were placed in an unheated greenhouse and subjected to environmental conditions often used for production of azaleas and camellias. Leachate from containers was collected weekly and monitored for pH, electrical conductivity, and concentrations of NH4+ N, NO3–N, total P and total K. Leachate concentrations of all nutrients were relatively high during the first 10 to 20 weeks of the study, and then gradually decreased during the remaining portion of the experiment. Differences were observed among fertilizer types, with Multicote often resulting in higher concentrations of N, P, and K in leachates compared to the leachates from the other fertilizer types during the first half of the study. Concentrations of NO3– and P from all fertilizer types were often above permissible levels as cited in the federal Clean Water Act.

scholarly journals Rates of Ammonium-nitrogen, Nitrate-nitrogen, Phosphorus, and Potassium from Two Controlled-release Fertilizers under Different Substrate Environments

2005 ◽  
Vol 15 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Timothy K. Broschat
Keyword(s):  
Controlled Release ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Deionized Water ◽  
Silica Sand ◽  
Release Rates ◽  
P Release ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus ◽  
Controlled Release Fertilizers

Five-gram (0.18 oz) samples of two controlled-release fertilizers (CRFs), Osmocote 15N–3.9P–10K (8–9 month) (OSM) and Nutricote 18N–2.6P–6.7K (type 180) (NUTR), were sealed into polypropylene mesh packets that were placed on the surface of a 5 pine bark: 4 sedge peat: 1 sand (by volume) potting substrate (PS), buried 10 cm (3.9 inches) deep below the surface of PS, buried 10 cm below the surface of saturated silica sand (SS), or in a container of deionized water only. Containers with PS received 120 mL (4.1 floz) of deionized water three times per week, but the containers with SS or water only had no drainage and were sealed to prevent evaporation. Samples were removed after 2, 5, or 7 months of incubation at 23 °C (73.4 °F) and fertilizer prills were crushed, extracted with water, and analyzed for ammonium-nitrogen (NH4-N), nitrate-nitrogen (NO3-N), phosphorus (P), and potassium (K). Release rates of NO3-N were slightly faster than those of NH4-N and both N ions were released from both products much more rapidly than P or K. After 7 months, OSM prills retained only 8% of their NO3-N, 11% of their NH4-N, 25% of their K, and 46% of their P when averaged across all treatments. Nutricote prills retained 21% of their NO3-N, 28% of their NH4-N, 51% of their K, and 65% of their P. Release of all nutrients from both fertilizers was slowest when applied to the surface of PS, while both products released most rapidly in water only. Release rates in water only exceeded those in SS, presumably due to lower rates of mass flow in SS.

scholarly journals Total Amino Acids by UHPLC–UV in Infant Formulas and Adult Nutritionals, First Action 2018.06

2019 ◽  
Vol 102 (5) ◽  
pp. 1574-1588 ◽  
Author(s):  
Greg Jaudzems ◽  
Joseph Guthrie ◽  
Sabine Lahrichi ◽  
Christophe Fuerer
Keyword(s):  
Amino Acids ◽  
Infant Formula ◽  
Amino Acid Content ◽  
Method Performance ◽  
Expert Review ◽  
Performance Requirements ◽  
Expert Review Panel ◽  
Single Laboratory ◽  
Total Amino Acids

Abstract Background: An acid hydrolysis ultrahigh-performance LC–UV method was evaluated for the determination of total amino acids in infant formula and adult/pediatric nutritional formula. Objective: It was assessed for compliance against AOAC INTERNATIONAL Standard Method Performance Requirements (SMPR®) established by the Stakeholder Panel for Infant Formula and Adult Nutritionals (SPIFAN). Methods: A single-laboratory validation (SLV) study was conducted as a first step in the process to validate the method. In this SLV, 17 SPIFAN matrices representing a range of infant formula and adult nutritional products were evaluated for their amino acid content. Results: The analytical range was found to be within the needs for all products; some may require a dilution. Evaluation of trueness performed on Standard Reference Material 1849a (Infant/Adult Nutritional Formula) showed all compounds met the SMPR theoretical value, with exceptions for threonine and tyrosine. These may have a bias for the National Institute of Standards and Technology (NIST) data, depending on hydrolysis used in the determination of the NIST certificate of analysis. Conclusions: Based on the results of this SLV, this method met the SMPR and was approved as a First Action method by the AOAC Expert Review Panel on Nutrient Methods on August 28, 2018.

Determination of Alkaloids in Mitragyna speciosa (Kratom) Raw Materials and Dietary Supplements by HPLC-UV: Single-Laboratory Validation, First Action 2017.14

2018 ◽  
Vol 101 (4) ◽  
pp. 964-965
Author(s):  
Elizabeth M Mudge ◽  
Paula N Brown
Keyword(s):  
Standard Method ◽  
Raw Materials ◽  
Review Panel ◽  
Method Performance ◽  
Performance Requirement ◽  
Expert Review ◽  
Mitragyna Speciosa ◽  
Expert Review Panel ◽  
Single Laboratory

Abstract The AOAC Expert Review Panel (ERP) approved a method for the quantitation of alkaloids in Mitragyna speciosa for consideration as First Action Official MethodSM status. The previously published method summarized a single-laboratory validation of two alkaloids, mitragynine and 7-hydroxymitragynine, in raw materials and finished products. The methods performance was compared with the AOAC Standard Method Performance Requirement 2015.008. With repeatability precision (RSDr) ranging from 0.51 to 0.95% and recoveries from 93.6 to 98.9% in the different product matrices, the ERP adopted the method and provided recommendations for achieving Final Action status.

Choline in Infant Formula and Adult Nutritionals by Ion Chromatography and Suppressed Conductivity: First Action 2012.20

2013 ◽  
Vol 96 (6) ◽  
pp. 1400-1406 ◽  
Author(s):  
Kassandra Oates ◽  
Lillian Chen ◽  
Brian De Borba ◽  
Deepali Mohindra ◽  
Jeffrey Rohrer ◽  
...  
Keyword(s):  
Infant Formula ◽  
Ion Chromatography ◽  
Method Performance ◽  
Expert Review ◽  
Performance Requirements ◽  
Technology Standard ◽  
Expert Review Panel ◽  
Suppressed Conductivity Detection ◽  
Single Laboratory

Abstract Single-laboratory validation (SLV) data from a method for the determination of choline in infant formula and adult nutritionals by ion chromatography (IC) and suppressed conductivity were generated and presented to the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Expert Review Panel (ERP) at the AOAC Annual Meeting held in Las Vegas, NV, during September 30 to October 3, 2012. The ERP reviewed the data and concluded that the data met the standard method performance requirements (SMPRs) established and approved the method as AOAC Official First Action. At the ERP's request, a second, full SLV was performed on 17 SPIFAN matrixes that included fortified and placebo products. Prior to IC analysis, microwave-assisted acid hydrolysis was used to digest and release bound choline from powder and ready-to-feed (RTF) infant formula and adult nutritional samples. Following hydrolysis, separation of choline from common cations was achieved on a Thermo ScientificTM DionexTM IonPacTM CS19 column followed by suppressed conductivity detection. Total choline was measured and reported as the choline ion in mg/100 g reconstituted material or RTF as-is. The system was calibrated over the analytical range specified in the SMPR (2–250 mg/100 g). Recoveries of spiked samples at 50 and 100% of the fortified choline amounts ranged from 93.1 to 100.7% with RSDs ≤6.7% for product containing <2 mg/100 g and ≤4.1% for product containing 2–100 mg/100 g. Accuracy for the National Institute of Standards and Technology Standard Reference Material 1849a was determined over a 6-day interval and found to be 10.2 ± 0.2 mg/100 g calculated as the reconstituted powder with an RSD of 1.8%. The LOD was determined to be 0.009, and the LOQ 0.012 mg/100 g, well below the SMPR requirements of 0.7 and 2 mg/100 g, respectively. Repeatability RSDs over the range of the assay (2–200 mg/100 g) ranged from 1.0 to 5.93%

Determination of Biotin in Infant, Pediatric, and Adult Nutritionals by High-Performance Liquid Chromatography and Fluorescence Detection: Single-Laboratory Validation, First Action 2016.11

2017 ◽  
Vol 100 (1) ◽  
pp. 145-151 ◽  
Author(s):  
Qi Lin ◽  
Yi Ding ◽  
Fiona Poh ◽  
Chunyan Zhang ◽  
Shang-Jing Pan ◽  
...  
Keyword(s):  
Fluorescence Detection ◽  
High Performance ◽  
Reversed Phase ◽  
Hplc Method ◽  
Intermediate Precision ◽  
Metaphosphoric Acid ◽  
Expert Review ◽  
Expert Review Panel ◽  
Single Laboratory

Abstract A reversed-phase HPLC method with postcolumn protein conjugation and fluorescence detection for the quantitative determination of biotin in infant, pediatric, and adult nutritionals was developed and evaluated in a single-laboratory validation (SLV). Sample of appropriate size is mixed with 2% metaphosphoric acid to precipitate out the protein. The filtrate is injected onto a C18 HPLC column in which biotin and riboflavin are separated with an appropriate mobile phase. The biotin, after eluting from the column, binds with the streptavidin fluorescein to become a fluorescent conjugate. The conjugate is then detected by fluorescence at λex = 495 nm and λem = 518 nm. A column switch is used in the method as an option to shorten the run time from 30 to 15 min, by eluting out riboflavin at a higher flow rate. In this SLV, a total of 19 AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals matrixes representing a range of infant,pediatric, and adult formulas were evaluated for their biotin content. The analytical range was 1.66–142 μg/100 g reconstituted final product. The repeatability and intermediate precision ranged from 0.5 to 3.0% RSDr and from 1.3 to 4.5% RSDiR, respectively. Recovery from spiked matrixes varied from 95 to 111%, and accuracy of quantification using Standard Reference Material 1849a ranged from 99 to 105%. The LOQ in reconstituted product was estimated to be 0.8 μg/100 g. The method was approved by the Expert Review Panel as First Action at the 2016 AOAC INTERNATIONAL Mid-Year Meeting.

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