1
|
Fedoros EI, Tyndyk ML, Popovich IG, Anikin IV, Yurova MN, Gubareva EA, Pigarev SE, Panchenko AV, Solovyev ND, Anisimov VN. Assessment of antitumor activity of BP-C1, a platinum-based anticancer agent with a lignin-derived polymeric ligand, in autochthonous induced and spontaneous carcinogenesis rodent models. J Trace Elem Med Biol 2022; 73:127013. [PMID: 35679766 DOI: 10.1016/j.jtemb.2022.127013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 04/18/2022] [Accepted: 05/27/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND A standard approach to study the anticancer activity of novel drugs is their testing in animals with inoculated tumors, which has some limitations. An alternative is the use of spontaneous or carcinogen-induced tumor models as they have better translation potential. The carcinogen-induced and transgenic tumor models were used to assess the antitumor activity of BP-C1, a platinum-containing drug with lignin-derived polymeric ligand. METHODS We used female Swiss-H-derived mice and Wistar female rats to induce autochthonous tumors via exposure to benzo[a]pyrene and 1,2-dimethylhydrazine, respectively. Additionally, transgenic HER-2/neu FVB/N female mice, prone to the development of spontaneous mammary carcinomas, were used. RESULTS Antitumor activity of BP-C1 was observed in soft tissue sarcomas, induced by benzo[a]pyrene. The animals treated with BP-C1 exhibited more stabilizations and therapy responses compared to placebo controls. The efficacy of BP-C1 was somewhat reduced compared to cyclophosphamide; however, their combination resulted in an enhanced antitumor effect. For the 1,2-dimethylhydrazine-induced rat colon cancer model, BP-C1 reduced tumor multiplicity by 21-41 %. For mammary adenocarcinomas in HER-2/neu FVB/N mice, short-termed complete responses were observed in the BP-C1 groups with a frequency of 12-13 %, while complete responses were absent in the placebo group. CONCLUSION The results acquired indicated a wide spectrum of antitumor activity of BP-C1.
Collapse
Affiliation(s)
- Elena I Fedoros
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia; Nobel Ltd., of. 333, 271A, pr. Obukhovskoy Oborony, Saint Petersburg 192012, Russia
| | - Margarita L Tyndyk
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia
| | - Irina G Popovich
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia
| | - Ivan V Anikin
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia
| | - Maria N Yurova
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia
| | - Ekaterina A Gubareva
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia
| | - Sergey E Pigarev
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia; Nobel Ltd., of. 333, 271A, pr. Obukhovskoy Oborony, Saint Petersburg 192012, Russia
| | - Andrey V Panchenko
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia
| | - Nikolay D Solovyev
- Atlantic Technological University, ATU Sligo, Ash Lane, Sligo F91 YW50, Ireland.
| | - Vladimir N Anisimov
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov National Medical Research Center of Oncology, 68, Leningradskaya Str., Pesochny, Saint Petersburg 197758, Russia
| |
Collapse
|
2
|
Drobyshev EJ, Solovyev ND, Gorokhovskiy BM, Kashuro VA. Accumulation Patterns of Sub-chronic Aluminum Toxicity Model After Gastrointestinal Administration in Rats. Biol Trace Elem Res 2018; 185:384-394. [PMID: 29441448 DOI: 10.1007/s12011-018-1247-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 01/11/2018] [Indexed: 01/08/2023]
Abstract
Although aluminum chronic neurotoxicity is well documented, there are no well-established experimental protocols of Al exposure. In the current study, toxic effects of sub-chronic Al exposure have been evaluated in outbreed male rats (gastrointestinal administration). Forty animals were used: 10 were administered with AlCl3 water solution (2 mg/kg Al per day) for 1 month, 10 received the same concentration of AlCl3 for 3 month, and 20 (10 per observation period) saline as control. After 30 and 90 days, the animals underwent behavioral tests: open field, passive avoidance, extrapolation escape task, and grip strength. At the end of the study, the blood, liver, kidney, and brain were excised for analytical and morphological studies. The Al content was measured by inductively coupled plasma mass-spectrometry. Essential trace elements-Co, Cr, Cu, Fe, Mg, Mn, Mo, Se, and Zn-were measured in whole blood samples. Although no morphological changes were observed in the brain, liver, or kidney for both exposure terms, dose-dependent Al accumulation and behavioral differences (increased locomotor activity after 30 days) between treatment and control groups were indicated. Moreover, for 30 days exposure, strong positive correlation between Al content in the brain and blood for individual animals was established, which surprisingly disappeared by the third month. This may indicate neural barrier adaptation to the Al exposure or the saturation of Al transport into the brain. Notably, we could not see a clear neurodegeneration process after rather prolonged sub-chronic Al exposure, so probably longer exposure periods are required.
Collapse
Affiliation(s)
- Evgenii J Drobyshev
- Institut für Ernährungswissenschaft, Universität Potsdam, Arthur-Scheunert-Allee 114-116, Nuthetal, 14558, Potsdam, Germany.
- St. Petersburg State University, St. Petersburg, Russia.
| | | | - Boris M Gorokhovskiy
- Institute of Precambrian Geology and Geochronology Russian Academy of Sciences, St. Petersburg, Russia
| | - Vadim A Kashuro
- Institute of Toxicology of Federal Medico-Biological Agency, St. Petersburg, Russia
| |
Collapse
|
3
|
Ganeev AA, Gubal AR, Lukyanov GN, Arseniev AI, Barchuk AA, Jahatspanian IE, Gorbunov IS, Rassadina AA, Nemets VM, Nefedov AO, Korotetsky BA, Solovyev ND, Iakovleva E, Ivanenko NB, Kononov AS, Sillanpaa M, Seeger T. Analysis of exhaled air for early-stage diagnosis of lung cancer: opportunities and challenges. Russ Chem Rev 2018. [DOI: 10.1070/rcr4831] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
4
|
Solovyev ND, Fedoros EI, Drobyshev EJ, Ivanenko NB, Pigarev SE, Tyndyk ML, Anisimov VN, Vilpan YA, Panchenko AV. Anticancer activity and tissue distribution of platinum (II) complex with lignin-derived polymer of benzene-poly-carboxylic acids. J Trace Elem Med Biol 2017; 43:72-79. [PMID: 27986470 DOI: 10.1016/j.jtemb.2016.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/30/2016] [Accepted: 11/16/2016] [Indexed: 02/06/2023]
Abstract
Platinum-containing antineoplastic agents with physiologically active ligands seem to be a promising direction in anticancer drug design. PDBA is a novel promising antineoplastic agent, containing polymer ligand of natural origin (international patent WO2013/143549 A1). Polymer ligand of PDBA has a highly functionalised polyphenolic backbone, which exerts its own pharmacological effect via immune modulation and regulation of gene expression. PDBA is a cis-diammineplatinum(II) complex, containing mono-deprotonated benzene-poly-carboxylic acids, derived from lignin, and hydroxyl group as O-donor ligands (approximate bulk formula C83H70N2O27Pt). The agent is being evaluated in Phase II controlled clinical trials in metastatic breast cancer patients. In the present study, tissue distribution and tumour growth inhibition effects of PDBA, cisplatin and carboplatin were compared in SHR female mice, bearing inoculated solid Ehrlich carcinoma. The agents were administered subcutaneously every second day for the period of 10days (5 injections) at 62.5mg/kg, 3.0mg/kg and 18.5mg/kg for PDBA, cisplatin and carboplatin, respectively. Experimental animals were sacrificed on the Days 11, 16 and 23 after the inoculation of the tumour. The doses of all studied drugs were selected to obtain similar antitumour efficacy with ca. 50% growth inhibition of the Ehrlich tumour at the end of the study. The efficacy of a single platinum reactive moiety [cis-diammineplatinum(II)] was shown to be the highest for cisplatin, followed by PDBA and finally carboplatin. However, the toxicity of PDBA was considerably lower than that of carboplatin and especially cisplatin. The drugs were mainly distributed in lungs, kidneys, liver, spleen and tumour tissue. PDBA showed quite high accumulation in the tumour tissue, possibly, owing to the effect of the lignin-derived ligand.
Collapse
Affiliation(s)
- Nikolay D Solovyev
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russian Federation.
| | - Elena I Fedoros
- RD Pharm LTD, St. Petersburg, Russian Federation; N.N. Petrov Research Institute of Oncology, St. Petersburg, Russian Federation
| | - Evgenii J Drobyshev
- N.N. Petrov Research Institute of Oncology, St. Petersburg, Russian Federation; Institute of Toxicology of Federal Medico-Biological Agency, St. Petersburg, Russian Federation
| | - Natalya B Ivanenko
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russian Federation; Institute of Toxicology of Federal Medico-Biological Agency, St. Petersburg, Russian Federation
| | - Sergey E Pigarev
- RD Pharm LTD, St. Petersburg, Russian Federation; N.N. Petrov Research Institute of Oncology, St. Petersburg, Russian Federation
| | - Margarita L Tyndyk
- N.N. Petrov Research Institute of Oncology, St. Petersburg, Russian Federation
| | - Vladimir N Anisimov
- N.N. Petrov Research Institute of Oncology, St. Petersburg, Russian Federation
| | - Yury A Vilpan
- Russian Scientific Centre 'Applied Chemistry', St. Petersburg, Russian Federation
| | - Andrey V Panchenko
- RD Pharm LTD, St. Petersburg, Russian Federation; N.N. Petrov Research Institute of Oncology, St. Petersburg, Russian Federation
| |
Collapse
|
5
|
Drobyshev EJ, Solovyev ND, Ivanenko NB, Kombarova MY, Ganeev AA. Trace element biomonitoring in hair of school children from a polluted area by sector field inductively coupled plasma mass spectrometry. J Trace Elem Med Biol 2017; 39:14-20. [PMID: 27908406 DOI: 10.1016/j.jtemb.2016.07.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/09/2016] [Accepted: 07/14/2016] [Indexed: 11/24/2022]
Abstract
In the current study, a biomonitoring of 18 hair trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Se, V, Zn, Ca, Na and P) in school children from Leningradskaya Oblast' is reported. A case group, residing in a proximity to the toxic waste disposal grounds (Krasniy Bor), has been assessed vs. controls from a non-urban settlement Seltso. In total, 166 hair samples were analysed using double focusing sector field inductively coupled plasma mass spectrometry after microwave-assisted sample digestion with nitric acid. For the determination of Ca, Na and P inductively coupled plasma optical emission spectrometry was employed. For the validation, a reference material and spiked hair samples were analysed. The data obtained was processed using parametric statistics and factor analysis. Determined concentrations of trace elements were in agreement with the previously published results on chemically polluted areas. In the case group, linear correlations between Al, Cr, Cu, Fe, Ni and V were observed. Also, these metals correlated to selenium hair content in the case group. Additionally, a correlation between hair Se and P was observed in the case subjects. Several gender differences in trace content were observed within each group. However, no age- or body index-related difference was found. The obtained results show that closely located waste disposal grounds intensifies trace element exposure in school children of Krasniy Bor. However, judging from rather high values for the controls, total environmental status of the region seems to be unstable, so additional monitoring and chemical safety measures are required.
Collapse
Affiliation(s)
- Evgenii J Drobyshev
- Institute of Toxicology of Federal Medico-Biological Agency, 192019 St. Petersburg, ul. Bekhtereva, 1, Russia
| | - Nikolay D Solovyev
- St. Petersburg State University, 199034 St. Petersburg, Universitetskaya nab., 7/9, Russia.
| | - Natalya B Ivanenko
- Institute of Toxicology of Federal Medico-Biological Agency, 192019 St. Petersburg, ul. Bekhtereva, 1, Russia; St. Petersburg State University, 199034 St. Petersburg, Universitetskaya nab., 7/9, Russia
| | - Maria Yu Kombarova
- Research Institute of Hygiene, Occupational Pathology and Human Ecology, Federal Medico-Biological Agency, 188663, Leningradskaya Oblast', Vsevolozhskiy District, Kuz'molovskiy, Kapitolovo, 93, Russia
| | - Alexander A Ganeev
- St. Petersburg State University, 199034 St. Petersburg, Universitetskaya nab., 7/9, Russia
| |
Collapse
|
6
|
Solovyev ND. Importance of selenium and selenoprotein for brain function: From antioxidant protection to neuronal signalling. J Inorg Biochem 2015; 153:1-12. [PMID: 26398431 DOI: 10.1016/j.jinorgbio.2015.09.003] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 09/03/2015] [Accepted: 09/09/2015] [Indexed: 12/21/2022]
Abstract
Multiple biological functions of selenium manifest themselves mainly via 25 selenoproteins that have selenocysteine at their active centre. Selenium is vital for the brain and seems to participate in the pathology of disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and epilepsy. Since selenium was shown to be involved in diverse functions of the central nervous system, such as motor performance, coordination, memory and cognition, a possible role of selenium and selenoproteins in brain signalling pathways may be assumed. The aim of the present review is to analyse possible relations between selenium and neurotransmission. Selenoproteins seem to be of special importance in the development and functioning of GABAergic (GABA, γ-aminobutyric acid) parvalbumin positive interneurons of the cerebral cortex and hippocampus. Dopamine pathway might be also selenium dependent as selenium shows neuroprotection in the nigrostriatal pathway and also exerts toxicity towards dopaminergic neurons under higher concentrations. Recent findings also point to acetylcholine neurotransmission involvement. The role of selenium and selenoproteins in neurotransmission might not only be limited to their antioxidant properties but also to inflammation, influencing protein phosphorylation and ion channels, alteration of calcium homeostasis and brain cholesterol metabolism. Moreover, a direct signalling function was proposed for selenoprotein P through interaction with post-synaptic apoliprotein E receptors 2 (ApoER2).
Collapse
Affiliation(s)
- Nikolay D Solovyev
- Institute of Chemistry, St. Petersburg State University, St. Petersburg 198504, Russian Federation.
| |
Collapse
|
7
|
Navolotskii DV, Ivanenko NB, Solovyev ND, Fedoros EI, Panchenko AV. Pharmacokinetics and tissue distribution of novel platinum containing anticancer agent BP-C1 studied in rabbits using sector field inductively coupled plasma mass spectrometry. Drug Test Anal 2015; 7:737-44. [PMID: 26061351 PMCID: PMC4744679 DOI: 10.1002/dta.1824] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/19/2015] [Accepted: 05/19/2015] [Indexed: 11/17/2022]
Abstract
A method of platinum quantification in whole blood samples after microwave digestion using sector field inductively coupled plasma mass spectrometry has been developed. The following analytical figures of merit have been established: limit of detection 1.1 µg/L for blood samples, dynamic range 3.6–200 µg/L, intra‐day precision (relative standard deviation, n = 9) did not exceed 5%. Spiked samples were analyzed for method validation. The method was used for pharmacokinetics studies of a novel anti‐cancer drug BP‐С1, a complex of cis‐configured platinum and benzene‐poly‐carboxylic acids. Main pharmacokinetic parameters (area under curve, maximum concentration, clearance, half‐life times for α‐ and β‐phase) were estimated for two dosage forms of BP‐C1 0.05 and 0.125 mass %. Pharmacokinetic curves were assessed for single and course administration. Studies were performed using rabbits (n = 6) as a model. BP‐C1 was injected intramuscularly. The study established dose proportionality of the tested dosage forms and suggested clinical dosing schedule: 5 days of injections followed by 2 days’ break. Platinum tissue distribution was studied in tissue samples collected 20 days after the last injection. Predominant platinum accumulation was observed in kidneys, liver, and muscles near injection site. ‘Slow’ phase of platinum excretion kinetics may be related to the muscles at the injection site. © 2015 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.
Collapse
Affiliation(s)
- Denis V Navolotskii
- Institute of Toxicology of Federal Medico-Biological Agency, St. Petersburg, Russian Federation
| | - Natalya B Ivanenko
- Institute of Toxicology of Federal Medico-Biological Agency, St. Petersburg, Russian Federation.,Institute of Chemistry, Saint Petersburg State University, St. Petersburg, Russian Federation
| | - Nikolay D Solovyev
- Institute of Chemistry, Saint Petersburg State University, St. Petersburg, Russian Federation
| | - Elena I Fedoros
- Nobel LTD, St. Petersburg, Russian Federation.,N.N. Petrov Research Institute of Oncology, St. Petersburg, Russian Federation
| | - Andrey V Panchenko
- N.N. Petrov Research Institute of Oncology, St. Petersburg, Russian Federation
| |
Collapse
|
8
|
Ivanenko NB, Solovyev ND, Ivanenko AA, Ganeev AA. Application of Zeeman graphite furnace atomic absorption spectrometry with high-frequency modulation polarization for the direct determination of aluminum, beryllium, cadmium, chromium, mercury, manganese, nickel, lead, and thallium in human blood. Arch Environ Contam Toxicol 2012; 63:299-308. [PMID: 22868581 DOI: 10.1007/s00244-012-9784-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Accepted: 07/05/2012] [Indexed: 06/01/2023]
Abstract
Determination of aluminum (Al), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), and thallium (Tl) concentrations in human blood using high-frequency modulation polarization Zeeman graphite furnace atomic absorption spectrometry (GFAAS) was performed. No sample digestion was used in the current study. Blood samples were diluted with deionized water or 0.1 % (m/v) Triton X-100 solution for Tl. Dilution factors ranged from 1/5 per volume for Be and Tl to 1/20 per volume for Cd and Pb. For Tl, Cd, and Hg, noble metals (gold, platinum, rhodium, etc.) were applied as surface modifiers. To mitigate chloride interference, 2 % (m/v) solution of NH(4)NO(3) was used as matrix modifier for Tl and Ni assessment. The use of Pd(NO(3))(2) as oxidative modifier was necessary for blood Hg and Tl measurement. Validation of the methods was performed by analyzing two-level reference material Seronorm. The precision of the designed methods as relative SD was between 4 and 12 % (middle of a dynamic range) depending on the element. For additional validation, spiked blood samples were analyzed. Limits of detection (LoDs, 3σ, n = 10) for undiluted blood samples were 2.0 μg L(-1) for Al, 0.08 μg L(-1) for Be, 0.10 μg L(-1) for Cd, 2.2 μg L(-1) for Cr, 7 μg L(-1) for Hg, 0.4 μg L(-1) for Mn, 2.3 μg L(-1) for Ni, 3.4 μg L(-1) for Pb, and 0.5 μg L(-1) for Tl. The LoDs achieved allowed determination of Al, Cd, Cr, Mn, Ni, and Pb at both toxic and background levels. Be, Hg, and Tl could be reliably measured at toxic levels only. The methods developed are used for clinical diagnostics and biological monitoring of work-related exposure.
Collapse
Affiliation(s)
- Natalya B Ivanenko
- Institute of Toxicology, Federal Medico-Biological Agency of Russia, Russian Federation, ul. Behtereva, 1, 192019 Saint Petersburg, Russia
| | | | | | | |
Collapse
|
9
|
Solovyev ND, Ivanenko NB, Ivanenko AA. Whole blood thallium determination by GFAAS with high-frequency modulation polarization Zeeman effect background correction. Biol Trace Elem Res 2011; 143:591-9. [PMID: 20922499 DOI: 10.1007/s12011-010-8865-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 09/22/2010] [Indexed: 10/19/2022]
Abstract
A new technique of blood thallium direct determination based on graphite furnace atomic absorption spectrometry with Zeeman background absorption correction system was designed. The developed technique does not require sample digestion. Sample treatment includes only a fivefold per volume dilution of blood sample with 0.1% (m/v) Triton X-100. L'vov integrated platform was modified with 400 μg of Rh. Matrix modifier (200 μg NH(4)NO(3) and 160 μg Pd(NO(3))(2)) was suggested for coping chloride and blood organic matter interferences. Standard reference material (Clincheck® Plasma Control for trace elements) analysis was used for validation. Additional validation was performed by analyzing spiked blood samples in the whole dynamic range. The dynamic range was 2-50 μg/L. Precision (RSD) was found <12%. Blood thallium limit of detection was 0.2 μg/L.
Collapse
|