Pesticide Residues in Some Polish Herbs

Round 1

Reviewer 1 Report

The manuscript agriculture-790091 entitled “Pesticide Residues in Some Polish Herbs” is focused on the screening of the content of pesticide residues in various herbal materials originating from eastern part of Poland. The subject of contamination of herbs is of topical interest, and therefore this paper is timely. On the other hand, many aspects of the manuscript need to be extensively improved. In my opinion, the authors should consider the following suggestions:

1. The English is readable, but some sentences are not finished and in some cases grammar and spelling errors occurs. The help of native English speaker would help to overcome this issue.
2. Experimental part is sufficiently written, but more details about HPLC-MS/MS method should be given. A table containing the retention windows, precursor ions, product ions and collision energies for each pesticides is needed.
3. The weakest part of manuscript is results and discussion. The results and discussion are presented in a very particular way that does not remark the interest of the results obtained. Some information on the method validation in the text would be very valuable. The addition of a Table or a Figure indicating the percentage of pesticides up or down a certain value of recovery, linearity and LOQ would be really illustrative on the method’s performance. Please, this Table or Figure should be included in the text.
4. The rational behind the pesticide selection needs to be included.
5. The quantification of the detected pesticides is not clear. Did you use matrix matched calibration curves? If yes, how many types of herbs were used for preparing matrix-matched calibration curves. Presumably these samples were previously analysed to ensure they were free of contamination?
6. Any explanation for finding azoxystrobine and linuron in big number of thyme. You need to explain what is the agrochemical function of these pesticides.

Allow me to suggest to the authors the vision of the following articles, which could be useful for the purpose of a greater organic unity of their work,
 -1- Páleníková, Agneša - Martinez-Dominguez, Gerardo - Arrebola, Francisco Javier – Romero-Gonzalez, Roberto - Hrouzková, Svetlana - Frenich, Antonia Garrido. Multifamily determination of pesticide residues in soya-based nutraceutical products by GC/MS-MS. In Food Chemistry. Vol. 173, (2015), 796-807.
 -2- Páleníková, Agneša - Martinez-Dominguez, Gerardo - Arrebola, Francisco Javier – Romero-Gonzalez, Roberto - Hrouzková, Svetlana - Frenich, Antonia Garrido. Occurrence of pesticide residues and transformation products in different types of dietary supplements. In Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment. Vol. 32, iss. 6 (2015), 849-856.
 -3- Páleníková, Agneša - Hrouzková, Svetlana. Nutraceutical Products-State-of-the-Art for Sample Preparation in Pesticide Residues Analysis. In Separation and Purification Reviews. Vol. 45, iss. 4 (2016), 288-304.

Author Response

Dear Reviewer

We would like to thank you for thoroughly reviewing the manuscript and their thoughtful criticism. We appreciate your suggestions and have revised the manuscript to address the comments and followed all suggestions to strengthen the manuscript.

I hope that my corrections will prove suitable enough for the demands of the publisher. I am still open to all further critical remarks and suggestions.

I look forward to hearing from you.

Comments:

The manuscript agriculture-790091 entitled “Pesticide Residues in Some Polish Herbs” is focused on the screening of the content of pesticide residues in various herbal materials originating from eastern part of Poland. The subject of contamination of herbs is of topical interest, and therefore this paper is timely. On the other hand, many aspects of the manuscript need to be extensively improved. In my opinion, the authors should consider the following suggestions:

General comments:

1. Experimental part is sufficiently written, but more details about HPLC-MS/MS method should be given. A table containing the retention windows, precursor ions, product ions and collision energies for each pesticides is needed –

• Taking into account the agricultural aspect of the work, some data was not included in the methodological part. The analyzes were carried out in an accredited laboratory, so the method and results meet international quality requirements. In connection with the reviewer's comment, I provide the required parameters in Table I and Table II. However, due to the agricultural orientation, I think that these tables can be omitted in the publication. Alternatively, these tables can be included as supplementary.

2. The weakest part of manuscript is results and discussion. The results and discussion are presented in a very particular way that does not remark the interest of the results obtained. Some information on the method validation in the text would be very valuable. The addition of a Table or a Figure indicating the percentage of pesticides up or down a certain value of recovery, linearity and LOQ would be really illustrative on the method’s performance. Please, this Table or Figure should be included in the text –

• The method for determining the content of pesticides is an accredited method (accreditation certificate AB 1375 https://www.pca.gov.pl/en/accredited-organizations/accredited-organizations/testing-laboratories/AB%201375,entity.html). The laboratory performing pesticide determinations has proven competence. Please find attached the analytical scope (pp. 6-10). The method is certified for matrices: herbs, fruits, vegetables, fruit juices. For herbs, thyme herb, mint leaf and black currant leaf matrices were tested. Due to the requirements of the certification authority, all analyzed pesticides were characterized by recovery in the range of 70% to 120%. The limiting criterion for linearity was the range above r³0.995 (values from 0.9950 to 0.9998 were obtained).

3. The rational behind the pesticide selection needs to be included –

• The choice of analyzed pesticides resulted from the demand of herbs producers' customers for analyzes in line with the laboratory services market in the region. In addition, only pesticides for which the criteria for analytical quality were met were included in the analysis.

4. The quantification of the detected pesticides is not clear. Did you use matrix matched calibration curves? If yes, how many types of herbs were used for preparing matrix-matched calibration curves. Presumably these samples were previously analysed to ensure they were free of contamination?

• Calibration curves were made in a clean matrix for three herbs (thyme herb, mint leaf and black currant leaf), which were previously prepared by the quechers method. Calibration was performed using internal standards (IS) - TPP in positive ionization mode and BNPU in negative ionization mode. To prepare the pesticide solution (Master Mix), stock solutions were made containing 15-20 compounds in a concentration of 1 mg / ml or 10 µg / ml. The Master Mix was made by mixing the stock solutions and supplementing them with a pure matrix extract, respectively, to obtain a concentration of 100 ng / ml.

5. Any explanation for finding azoxystrobine and linuron in big number of thyme. You need to explain what is the agrochemical function of these pesticides - corrected as recommended by the reviewer.

6. The English is readable, but some sentences are not finished and in some cases grammar and spelling errors occurs. The help of native English speaker would help to overcome this issue – language correction of text (grammar, usage, and overall readability of the manuscript) I have entrusted my colleague Paweł Pasikowski (Translator and Interpreter, English Language Instructor).

Author Response File: Author Response.pdf

Reviewer 2 Report

In general, the article presents the detail information about pesticide residues, which were determined in 104 samples of herbal raw material after their cultivation. The very important is comparison of datas with the results of foreign literatute.

The introduction of the article is very general focused on global topics around herbal production. Of course, sufficient plant raw-materials for various types of industries (pharmaceutical, food, beverage etc.) can only be ensured by large-scale cultivation of special plants, where in many cases pesticides are used. Perhaps it would be appropriate to describe more specifically the small- and large- scale cultivation of medicinal plants in Poland with an emphasis on individual herb species and the use of different pesticides directly in the fields.

Material and methods are described adequately. I appreciate the use of quality analytical methods (GC, HPLC / MS and MS/MS) in order to determining of a large amount of organic pesticide residuals.

Results are described in great details to each plant sample. However, I do not understand why analyzes of thyme herbage absolutely prevail. The proportion of the number of thyme samples and number of samples from other plants is very uneven. If the quantitative and qualitative contents of pesticide resudues were be determined for many plant species in a lot of replicates, the article would be more useful for herbal cultivation practice.

In the context of the discussion, I appreciate the detailed comparis of information on the determination of pesticide residues in the cultivation of special crops in several countries of the world.

Conclusion is very general. I agree with the author that there is a need for continue monitoring of the use of pesticides and their residual quantities of plant raw-material, especially in the production of medicinal, aromatic and spice plants.

However, my opinion is during the high occurence of weeds, pests and diseases of plant cutivation, there can be used the newest knowledges from the biological (ecological) and integrate plant protection. Protection of medicinal plants against harmful factors uses every possible method - agricultural, ecological or toxicological for the control of them under the minimal threshold of harmfulness.

In the case of application of chemical preparations - pesticides to the medicinal and aromatic plant fields, the period of protection must be kept, what is determined by the application date. It means in the practice, that the time between application and harvest must be longer than the time necessary for decompose of pesticide active substances.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer

We would like to thank you for thoroughly reviewing the manuscript and their thoughtful criticism. We appreciate your suggestions and have revised the manuscript to address the comments and followed all suggestions to strengthen the manuscript.

I hope that my corrections will prove suitable enough for the demands of the publisher. I am still open to all further critical remarks and suggestions.

I look forward to hearing from you.

Comments:

In regard to my opinion the contents of the manuscript in line with policy of the journal, the text has been prepared according to the format and style of journal including the body of the manuscript, page size and referencing. The literature citations are adequate enough and finally the manuscript does not contain any irrelevant information’s. The manuscript should be accepted in the form after its correction. Publish as received or with major corrections in regard to the English grammar (in many cases very long sentences are used).

General comments:

1. Perhaps it would be appropriate to describe more specifically the small- and large- scale cultivation of medicinal plants in Poland with an emphasis on individual herb species and the use of different pesticides directly in the fields.– corrected as recommended by the reviewer.
2. Conclusion is very general. I agree with the author that there is a need for continue monitoring of the use of pesticides and their residual quantities of plant raw-material, especially in the production of medicinal, aromatic and spice plants. However, my opinion is during the high occurence of weeds, pests and diseases of plant cutivation, there can be used the newest knowledges from the biological (ecological) and integrate plant protection. Protection of medicinal plants against harmful factors uses every possible method - agricultural, ecological or toxicological for the control of them under the minimal threshold of harmfulness- corrected as recommended by the reviewer.
3. In the case of application of chemical preparations - pesticides to the medicinal and aromatic plant fields, the period of protection must be kept, what is determined by the application date. It means in the practice, that the time between application and harvest must be longer than the time necessary for decompose of pesticide active substances - corrected as recommended by the reviewer.
4. Publish as received or with major corrections in regard to the English grammar (in many cases very long sentences are used) – corrected as recommended by the reviewer, language correction of text (grammar, usage, and overall readability of the manuscript) I have entrusted my colleague Paweł Pasikowski (Translator and Interpreter, English Language Instructor.).

Yours sincerely

Grażyna Kowalska

Reviewer 3 Report

The manuscript under revision analyse the content of 250 pesticides in 104 samples of herbal material. Using a standard analytical methodology based on QuECheRS extraction (using QuECheRS mix form Agilent) and LC-MS/MS analysis, the authors observed that 72.1% of samples of herbal material contained pesticide residues, and in 11.5% of those the maximum allowable concentrations of residue were exceeded.

This is a simple piece of research, well presented and organize and the manuscript fits into the scope of the Agriculture. However, this works seems not to have enough novelty form the analytical point of view, or at least, this novelty has not been sufficiently highlighted in the manuscript. Although the results of this paper can provide useful information to the local Polish authorities, it does not seem to provide any novelty for the scientific community.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The manuscript has been significantly improved and now warrants publication in Agriculture. 

Reviewer 3 Report

The manuscript has been substantially improved and the interest for the scientific community is now clear.