Automated Method for Determining Direct Available P2O5 in Fertilizers

1974 ◽  
Vol 57 (4) ◽  
pp. 785-790
Author(s):  
Larry L Wall ◽  
Charles W Gehrke
Keyword(s):  
Sampling Rate ◽  
Gravimetric Method ◽  
Ammonium Citrate ◽  
Slight Effect ◽  
Flow Rates ◽  
Automated Method ◽  
Accuracy And Precision ◽  
Analytical System ◽  
Hydrolysis Of ◽  
Heating Bath

Abstract In the automated method for the analysis of direct available and total P205 in fertilizers, a heating bath is used to destroy ammonium citrate and colored material and for hydrolysis of non-orthophosphates. The heating bath was maintained at 98°C and contained a 40' time delay coil, providing 15 min digestion. Improvements on the method for the automated digestion of citrate extracts of fertilizer included decreasing the reagent and sample flow rates by factors of 2 to 5. All of the citrate in those samples containing the highest levels of citrate was not destroyed; however, the slight effect of the remaining citrate could be eliminated by changing the concentration of the molybdovanadate reagent. No difficulty was encountered with the hydrolysis of non-orthophosphates. With this analytical system, steady state conditions were reached at a sampling rate of 40 samples/hr and with a 4 : 1 sample-to-wash ratio. Repeated analyses were made on 9 samples, and the accuracy and precision of results obtained by the automated method compared very well with data by the official AOAC gravimetric method.

Automated Method for the Determination of Direct Available P2O5 in Fertilizers

1973 ◽  
Vol 56 (5) ◽  
pp. 1078-1083
Author(s):  
Larry G Hambleton
Keyword(s):  
Primary Standard ◽  
Sampling Rate ◽  
Gravimetric Method ◽  
Ammonium Citrate ◽  
Photometric Method ◽  
Ferric Pyrophosphate ◽  
Color Development ◽  
Automated Method ◽  
Significant Difference ◽  
Coloring Matter

Abstract An automated photometric method for the analysis of direct available P2O5 in fertilizers has been developed. The method utilizes basic AutoAnalyzer equipment along with a heating bath to destroy ammonium citrate and coloring matter and also to hydrolyze non-orthophosphates. The 0.15 and 0.35 mg P2O5/ml ranges are expanded to read 10 and 90% T, respectively, with a sampling rate of 30 analyses/ hr. Experiments were conducted to show the effect of acid and ammonium citrate concentrations on color development. The normality of acid needed to completely hydrolyze the phosphorus in non-orthophosphate samples was also determined. Results for samples of urea-ammonium polyphosphate, sodium pyrophosphate, sodium metaphosphate, and ferric pyrophosphate analyzed by the automated method are reported and compared to results on the same samples analyzed by the official final action gravimetric quinolinium molybdophosphate method, 2.023–2.025; good agreement was shown between the methods. Six replicate determinations on 5 mixed fertilizer samples and a KH2PO4 primary standard by each method were in close agreement. The accuracy of the automated method was confirmed by analyzing 312 routine fertilizer samples by both the automated method and the gravimetric method; results did not show a significant difference when compared by Students’ l-test at the 5% level.

Automation of the AOAC Photometric Phosphomolybdovanadate Method for Direct Available P2O5

1966 ◽  
Vol 49 (6) ◽  
pp. 1213-1218
Author(s):  
Charles W Gehrke ◽  
James H Baumgartner ◽  
James P Ussary
Keyword(s):  
Sampling Rate ◽  
Gravimetric Method ◽  
Photometric Method ◽  
Available Phosphorus ◽  
Automatic Method ◽  
Average Recovery ◽  
Automated Method ◽  
Relative Standard ◽  
Standard Deviations

Abstract An automatic photometric method utilizing the Technicon AutoAnalyzer has been developed to determine phosphorus in all forms of fertilizer phosphorus in the range of 2.0–4.5 mg P2O5/100 ml at a sampling rate of 40 analyses/hr. Multiple analyses of KH2PO4, 9 Magruder check samples, and numerous commercial fertilizers were made and compared with results obtained by the official quinolinium phosphomolybdate method, 2.025(b). Average range for five independent determinations was 0.22% P2O5 for the automated method and 0.26% P2O5 for the gravimetric method; average relative standard deviations were 0.44 and 0.60%, respectively. The average recovery of P2O5 from KH2PO4 was 99.8% with the photometric method and 100.3% with the quinolinium method. Results on 69 commercial fertilizers containing 5–54% P2O5 by the automatic method were only 0.02%% lower than those by the gravimetric quinolinium method. Results show that the automated phosphomolybdovanadate method for direct available phosphorus in fertilizers is accurate, precise, and less time consuming for routine control and industrial laboratories.

Automated Urease-Chromous Method for Determining Nitrogen in Fertilizers

1979 ◽  
Vol 62 (3) ◽  
pp. 503-508 ◽  
Author(s):  
Larry L Wall ◽  
Charles W Gehrke
Keyword(s):  
Sample Preparation ◽  
Sampling Rate ◽  
Screening Method ◽  
Colorimetric Method ◽  
Diammonium Phosphate ◽  
Automated Method ◽  
Relative Standard ◽  
Single Method ◽  
Analytical System ◽  
And Control

Abstract An automated urease-chromous colorimetric method (AUCM) has been developed for determining nitrogen in fertilizers. The method is applicable to fertilizer samples that contain only ammoniacal, nitrate, and urea nitrogen. The concept of this method, combining nitrate reduction and enzymatic urea hydrolysis to produce a single method for total nitrogen, is new. The AUCM is an almost totally automated method with only an acidic dissolution step as the manual sample preparation. The urea is hydrolyzed to ammonia and carbon dioxide with urease, and the nitrate is reduced to ammonia with chromous ion within the continuous flow analytical system. The final step, also within the analytical system, is the spectrophotometric measurement of the ammonia, employing the ammonia-salicylate-hypochlorite chemistry. The sampling rate is 30 samples/hr. The method is not applicable to fertilizer samples containing refractory organic nitrogen forms, water-insoluble nitrogen, or significant levels of biuret. The average per cent nitrogen recovery by the AUCM for ammonium nitrate-diammonium phosphate bulk-blended fertilizer samples was 99.7, suspensions and liquids 99.7, urea fertilizers 97.8, and urea-diammonium phosphate bulk blends 98. The relative standard deviation for the analytical system was 0.40%, and for the method, 0.70%. The sample preparation is short and simple. This method offers many advantages as a screening method for fertilizer industry and control laboratories.

Evaluation of chemotherapy preparation processes: Volumetric method reliability and gravimetric method utility within 5 US hospitals

2021 ◽  
Author(s):  
Adam Moss ◽  
Stephanie Kang ◽  
Kathryn Morbitzer ◽  
Lam Nguyen ◽  
Moe Shwin ◽  
...  
Keyword(s):  
Gravimetric Method ◽  
The United States ◽  
Volumetric Method ◽  
Preparation Process ◽  
Accuracy And Precision ◽  
Data Collection Process ◽  
Accurate Dose ◽  
Actual Volume ◽  
Drug Expenditures ◽  
Transfer Device

Abstract Disclaimer In an effort to expedite the publication of articles , AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose The primary aim of this study was to investigate the accuracy of the volumetric method for intravenous (IV) preparations and explore the utility of gravimetric methods in the medication preparation process within multiple institutions. Secondary outcomes of this study were syringe size percent variations and impact on drug expenditures. Methods A prospective, noninterventional, multisite study was conducted between March 2015 and December 2016 to generate baseline estimates of accuracy and precision in the volumetric medication preparation process. Five hospitals in the United States were recruited for study participation. During the data collection process, technicians were required to measure the syringe at 3 different points: when the new empty syringe was connected to a closed-system transfer device (CSTD), when the filled syringe containing the prepared dose of medication was connected to a CSTD, and when the used syringe with residual medication was connected to a CSTD. The actual dose of drug dispensed (in mg) was divided by the specific gravity of the medication to determine the actual volume of medication dispensed. Results A total of 4,443 compounded sterile products representing 60 medications across 5 hospitals were eligible for the study. Of the evaluated preparations, 91.92% were within 5% of the prescribed dose and 96.56% were within 10% of the prescribed dose. The outliers ranged from –144.10% to 233.72%. Conclusion The potential for significant over- and undertreatment of an individual patient receiving IV chemotherapy exists, indicating the need for an additional measurement method, such as real-time gravimetric verification, to ensure an accurate dose is administered to every patient.

Automatic Method for the Determination of Calcium in the Presence of Magnesium and Phosphate Ions

1966 ◽  
Vol 12 (7) ◽  
pp. 418-427 ◽  
Author(s):  
Preston Smith ◽  
Caroline H Kurtzman ◽  
Mary E Ambrose
Keyword(s):  
Citric Acid ◽  
Automatic Method ◽  
Magnesium Ions ◽  
Phosphate Ions ◽  
Automated Method ◽  
Manual Analysis ◽  
Accuracy And Precision ◽  
Indicator Dyes ◽  
Indicator Dye

Abstract A direct spectrophotometric method for manual analysis of calcium using the indicator dye Eriochrome Blue S. E. was selected for automation. Most indicator dyes used have been somewhat unstable in solutions sufficiently alkaline to minimize the interference of magnesium. Eriochrome Blue S. E., when kept in an ice bath in the absence of light, permitted the use of sufficient alkali to remove interfering magnesium ions. Magnesium did not interfere in concentrations up to 12 mg./100 ml. when added to standards. The addition of 0.5% (w/v) citric acid removed interference of phosphate in concentrations up to 300 mg./100 ml. The automated method has the advantage of speed, yet retains the accuracy and precision of the conventional methods used for determining calcium.

Missouri Automated Method for Total Nitrogen in All Fertilizers

1971 ◽  
Vol 54 (3) ◽  
pp. 651-657 ◽  
Author(s):  
Charles W Gehrke ◽  
Larry L Wall ◽  
John S Killingley ◽  
Kazuyoshi Inada
Keyword(s):  
Sampling Rate ◽  
Automated System ◽  
Commercial Fertilizer ◽  
Sodium Tartrate ◽  
Color Development ◽  
Colorimetric System ◽  
Automated Method ◽  
Solid Liquid ◽  
Interfering Ions ◽  
Effective Analysis

Abstract An automated spectrophotometric method, utilizing Technicon AutoAnalyzer modules, has been developed for the analysis of nitrogen in fertilizers. The continuous digestor, which was found to effectively digest organic materials in solution after the reduction step, is coupled with an automated colorimetric system. This colorimetric system employs the ammonia-phenate-hypochlorite reaction. The fertilizer samples are reduced manually via the comprehensive nitrogen method (CNM). The sampling rate chosen is 30 cups/hr (6 reference standards included) which yields an effective analysis rate of 24 samples/hr. The impinger mixer at the exit end of the digestor helix is replaced with a jacketed double-mixing coil and an AO glass fitting for a more stable baseline and improved precision. Manganous ions at a concentration of 5.0 ppm introduced into the color development manifold as a catalyst give a significant increase in sensitivity. When commercial fertilizer samples were analyzed with the automated system, consistently low results were obtained for some samples as compared to results obtained by the AOAC CNM. However, 0.01M potassium sodium tartrate in the color development manifold provides sufficient complexing potential to eliminate the effect of interfering ions. One hundred commercial fertilizer samples including solid, liquid, and suspension fertilizers were analyzed by the Missouri automated nitrogen method. The results agreed well with the results obtained by multiple independent analyses by the AOAC CNM. Details of the automated system, sample preparation, reagent concentrations and preparation, and experimental data are given.

Automated Fluorometric Method for the Determination of Total Vitamin C in Food Products

1976 ◽  
Vol 59 (6) ◽  
pp. 1244-1250 ◽  
Author(s):  
Ram B Roy ◽  
Aldo Conetta ◽  
Jerry Salpeter
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Food Products ◽  
Total Vitamin ◽  
Automated Method ◽  
Highly Sensitive ◽  
Aoac Method ◽  
Analytical System

Abstract A specific microfluorometric method for the determination of ascorbic acid, dehydroascorbic acid, and total vitamin C in food products has been automated. The procedure developed is an adaptation of the official AOAC method (secs. 43.056–43.062), except that N-bromosuccinimide is used instead of Norit to oxidize vitamin C. Ascorbic acid is selectively oxidized by N-bromosuccinimide before other interfering substances that may be present, so this method is a highly sensitive and specific technique with extensive applicability. The proposed automated method is simple, rapid, reliable, and sufficiently sensitive to analyze as little as 2 × 10−3 to 0.1 mg ascorbic acid/ml. Analytical results obtained for ascorbic acid, dehydroascorbic acid, and total vitamin C in a wide variety of food products are reported. The analytical system developed has the capability of analyzing 50 samples/hr.

scholarly journals An Automated and High-Throughput Immunoaffinity Magnetic Bead-Based Sample Clean-Up Platform for the Determination of Aflatoxins in Grains and Oils Using UPLC-FLD

Toxins ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 583 ◽  
Author(s):  
Zhihong Xuan ◽  
Jin Ye ◽  
Bing Zhang ◽  
Li Li ◽  
Yu Wu ◽  
...  
Keyword(s):  
High Throughput ◽  
High Performance ◽  
Cost Effective ◽  
Magnetic Bead ◽  
The Novel ◽  
Analysis Method ◽  
Automated Method ◽  
Accuracy And Precision ◽  
Optimized Conditions

Sample clean-up remains the most time-consuming and error-prone step in the whole analytical procedure for aflatoxins (AFTs) analysis. Herein, an automated and high-throughput sample clean-up platform was developed with a disposable, cost-effective immunoaffinity magnetic bead-based kit. Under optimized conditions, the automated method takes less than 30 min to simultaneously purify 20 samples without requiring any centrifugation or filtering steps. When coupled to ultra-high performance liquid chromatography with fluorescence detection, this new analysis method displays excellent accuracy and precision as well as outstanding efficiency. Furthermore, an interlaboratory study was performed in six laboratories to validate the novel protocol. Mean recovery, repeatability, reproducibility, and Horwitz ratio values were within 91.9%–107.4%, 2.5%–7.4%, 2.7%–10.6%, and 0.26%–0.90, respectively. Results demonstrate that the developed sample clean-up platform is a reliable alternative to most widely adopted clean-up procedures for AFTs in cereals and oils.

scholarly journals Passive air sampling of gaseous elemental mercury: a critical review

2016 ◽  
Vol 16 (5) ◽  
pp. 3061-3076 ◽  
Author(s):  
David S. McLagan ◽  
Maxwell E. E. Mazur ◽  
Carl P. J. Mitchell ◽  
Frank Wania
Keyword(s):  
Sampling Rate ◽  
Elemental Mercury ◽  
Personal Exposure ◽  
Atmospheric Mercury ◽  
Uptake Capacity ◽  
Reliable Determination ◽  
Analytical Technique ◽  
Gaseous Elemental Mercury ◽  
Accuracy And Precision

Abstract. Because gaseous elemental mercury (GEM) is distributed globally through the atmosphere, reliable means of measuring its concentrations in air are important. Passive air samplers (PASs), designed to be cheap, simple to operate, and to work without electricity, could provide an alternative to established active sampling techniques in applications such as (1) long-term monitoring of atmospheric GEM levels in remote regions and in developing countries, (2) atmospheric mercury source identification and characterization through finely resolved spatial mapping, and (3) the recording of personal exposure to GEM. An effective GEM PAS requires a tightly constrained sampling rate, a large and stable uptake capacity, and a sensitive analytical technique. None of the GEM PASs developed to date achieve levels of accuracy and precision sufficient for the reliable determination of background concentrations over extended deployments. This is due to (1) sampling rates that vary due to meteorological factors and manufacturing inconsistencies, and/or (2) an often low, irreproducible and/or unstable uptake capacity of the employed sorbents. While we identify shortcomings of existing GEM PAS, we also reveal potential routes to overcome those difficulties. Activated carbon and nanostructured metal surfaces hold promise as effective sorbents. Sampler designs incorporating diffusive barriers should be able to notably reduce the influence of wind on sampling rates.

scholarly journals SYNTHESIS AND CHARATERISATION OF RICE HUSK SILICA BASED BOROSILICATE (B2SiO5) CERAMIC BY SOL-GEL ROUTES

2011 ◽  
Vol 11 (1) ◽  
pp. 85-89 ◽  
Author(s):  
Simon Sembiring
Keyword(s):  
Functional Groups ◽  
Rice Husk ◽  
Boron Oxide ◽  
Chemical Resistance ◽  
Sol Gel ◽  
Gravimetric Method ◽  
Spectroscopic Technique ◽  
X Ray Diffraction ◽  
Rice Husk Silica ◽  
Hydrolysis Of

In this research, borosilicate ceramics were produced from rice husk silica. Preparation of borosilicate ceramics was conducted by mixing boron oxide sol from borax with silica sol extracted from rice husk. The boron oxide was produced by hydrolysis of borax using H2SO4 5%. The samples were synthesized with different compositions, with the ratios of silica to boron oxide are 8:1, 8:2, 8:3 and 8:4. The samples were sintered at 900 °C. Functional groups were examined using FTIR spectroscopic technique. Structural and microstructural characteristics were examined by XRD and SEM, respectively. The chemical resistance of borosilicate is evaluated by gravimetric method using H2SO4, HCl, NaOH and KOH. The FTIR study revealed that the main functional groups are Si-O-Si, B-O-B, and B-O-Si. The x-ray diffraction (XRD) study revealed that the main crystalline phases are borosilicate (B2SiO5) and boron oxide (B2O3). SEM investigations clearly demonstrated that the smaller particle size was found with increasing in boron oxide concentration. From the chemical resistance test carried out, it was obtained that the produced borosilicate possessed high resistance to acids and alkalis.

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