This is very clearly demonstrated in every instrument manual. The procedure described by the author in his reply is absolutely wrong, quote " Five mL 5% sodium pyrophosphate (pH 7.0) solution was added to 50 mL of the water sample; pH of the mixture was adjusted at 7.0 using 0.1 M HCl " . It is very clear from their reply that the authors have neither read the manual of the instrument nor do they have any basic knowledge of laser fluorimetry measurement techniques.
In their correspondence vide publication: Uranium Concentration in Groundwater in Hisar City, India by Garg VK, Yadav A, Singh K, et al., Int J Occup Environ Med 2014; 5:112-114, the authors have described as quote " Uranium analysis was performed by laser fluorimetry method as described elsewhere and cited reference number 8, which is :Campen W, Bächmann K. Laser-induced fluorescence for the direct determination of small concentrations of uranium in water. Microchimica Acta 1979;72:159-70".
This reference 8 is for UA-3 Uranium Analyser ( Scientrix Ltd , Canada). They have tested the performance of the instrument. In UA-3 uranium analyser , where FLURAN -- has been used as fluorescence enhancing reagent. This reference has no relevance.
While the instrument described by author is Model UA-1, Quantalase, Indore, India.
Moreover, stating that " Error bars in the diagram represent the 95% confidence interval for the mean concentration of water samples measured at each place (reflecting the uncertainties in the measurement in different replicates of a sample). It is not necessary that bars are concentration-dependent". This is incorrect.
The authors are not aware of the fact that use of HCl should be avoided . Halides are strong quencher of uranyl fluorescence.
In my opinion, such publications should be retracted.
The functions of fluorescence enhancing buffer:
1. The primary function of fluorescence enhancing reagent is the formation of a single fluorescent uranyl species,
2. It also acts as a strong complexing agent for other metals in solution to reduce their effects on uranyl fluorescence,
3. It also contains a buffer to maintain optimum pH for both luminescence and masking efficiency.
There is no need to maintain the pH as described by authors: The procedure described by the author in his reply is absolutely wrong, quote " Five mL 5% sodium pyrophosphate (pH 7.0) solution was added to 50 mL of the water sample; pH of the mixture was adjusted at 7.0 using 0.1 M HCl " . It is very clear from their reply that the authors have neither read the manual of the instrument nor do they have any basic knowledge of laser fluorimetry measurement techniques.
The authors are not aware of the fact that use of HCl should be avoided . Halides are strong quencher of uranyl fluorescence.
Moreover, stating in the reply that " Error bars in the diagram represent the 95% confidence interval for the mean concentration of water samples measured at each place (reflecting the uncertainties in the measurement in different replicates of a sample). It is not necessary that bars are concentration-dependent". This is incorrect.
.Absolute and Relative Error
Absolute and relative error are two types of error with which every experimental scientist should be familiar. The differences are important.
The procedure described by the author in his reply is absolutely wrong, quote " Five mL 5% sodium pyrophosphate (pH 7.0) solution was added to 50 mL of the water sample; pH of the mixture was adjusted at 7.0 using 0.1 M HCl " . It is very clear from their reply that the authors have neither read the manual of the instrument nor do they have any basic knowledge of laser fluorimetry measurement techniques.
Moreover, stating that " Error bars in the diagram represent the 95% confidence interval for the mean concentration of water samples measured at each place (reflecting the uncertainties in the measurement in different replicates of a sample). It is not necessary that bars are concentration-dependent". This is incorrect.
In my opinion, Such spread of errors may be because of incorrect procedure adopted by the authors or other human errors such as variations due to co-precipitations etc due to the time interval between sampling and analysis.
In any analytical measurement, procedure of measurement strict adherence to various steps is a mandatory requirement for a reliable measurement. A good model such as a timetable for a train ( or a recipe for a cake) does not guarantee that the train is on time ( or that the cake is all right).
Human errors such as adoption of incorrect procedure, improper sampling and preservation, improper functioning of instrument( fluctuations), reagent blanks, etc all contribute to measurement errors.
The procedure described by the author in his reply is absolutely wrong, quote " Five mL 5% sodium pyrophosphate (pH 7.0) solution was added to 50 mL of the water sample; pH of the mixture was adjusted at 7.0 using 0.1 M HCl " . It is very clear from their reply that the authors have neither read the manual of the instrument nor do they have any basic knowledge of laser fluorimetry measurement techniques.
Moreover, stating that " Error bars in the diagram represent the 95% confidence interval for the mean concentration of water samples measured at each place (reflecting the uncertainties in the measurement in different replicates of a sample). It is not necessary that bars are concentration-dependent". This is incorrect.
In my opinion, Such spread of errors may be because of incorrect procedure adopted by the authors or other human errors such as variations due to co-precipitations etc due to the time interval between sampling and analysis.
In my opinion,such publications should be retracted .
Laser fluorimetry has been widely used since more than three decades for the direct determination of uranium in water samples at ppb level. Recently, LED-fluorimeters were introduced by: Quantalase - Services
http://quantalase.in/services
Quantalase. ... Quantalase Enterprises Private Limited. 229,Vigyan Nagar Near Alpine Public School Indore, MP 452012 ph: 0731 2322707 fax: 0731 2322708
Dilip Bhawalkar ( email:[email protected])
Director at Quantalase Enterprises Pvt. Ltd.
If any expert /analytical chemist carrying out uranium determination in water samples using laser fluorimetry, one can easily point out the large variation in measurement results ( Fig1. From the publication in The IJOEM.
( Garg VK, Yadav A, Singh K, et al. Uranium concentration in groundwater in Hisar city, India. Int J Occup Environ Med 2014;5:112-114). Variations at Such concentration levels are practically impossible , using Laser Fluorimetry as stated by author citing a reference 8 , which is for different laser fluorimeter (UA-3 Uranium Analyser (Scintrex Limited, Concord, Ontario, Canada).
But, From the Author’s Reply: Stating the Model UA-1, Quantalase, Indore, India was used for uranium determination.
One can easily make out that Model UA-1, Quantalase, Indore, India instrument is not a Laser Fluorimeter and also the procedure described is incorrect.
Model UA-1, Quantalase, Indore, India instrument is a Pulsed LED-Fluorimeter
So , by reading carefully all the three papers, one can easily find out the Research misconduct by authors:
1. Author paper( Garg VK, Yadav A, Singh K, et al. Uranium concentration in groundwater in Hisar city, India. Int J Occup Environ Med 2014;5:112-114.),
2. Author’s Reply
( Rathore DPS. Comments on uranium concentration in groundwater in Hisar city, India. Int J Occup Environ Med 2014;5: Online first, available from: www.theijoem.com/ijoem/index.php/ijoem/article/ view/445. And
3. Authors paper Published in J Radioanal Nucl Chem(Singh B, Garg VK, Yadav P, et al. Uranium in groundwater from western Haryana, India. J Radioanal Nucl Chem 2014. DOI 10.1007/s10967-014-3133-y).
Authors are advised to update.
an interesting paper on uranium:
Article Advances in technologies for the measurement of uranium in d...
An article has been published based on the above observation:
Letter to the Editor: Comments related to the publication titled " Uranium in ground water from Western Haryana, India" by Balvinder Singh, V.K.Garg, PoonamYadav, Nawal Kishore,Vandana Pulhani, J Radioanal Nucl Chem, DOI 10.1007/s10967-014-3133-y, Published online: 13 April 2014,
D.P.S.RATHORE,Journal of Radioanalytical and Nuclear Chemistry (Impact Factor: 1.47). 09/2014; 302(1):745-746. DOI: 10.1007/s10967-014-3392-7
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