Intra- and Inter-Day Element Variability in Human Breast Milk: Pilot Study
Abstract
:1. Introduction
2. Materials and Methods
2.1. Reagents and Standard Solutions
2.2. Study Participants and Breast Milk Collection
2.3. Sample Preparation
2.4. Protein Assay and Fat/Calorie Measurement
2.5. Instrument Analysis
2.6. Quality Control
2.7. Potential Covariates
2.8. Statistical Analysis
3. Result and Discussion
3.1. Method Performance Characteristics
3.1.1. Pre-Treatment
3.1.2. ICP-MS/MS Conditions
3.1.3. Precision, Accuracy, and Robustness
3.2. Toxic Element Levels and Fat and Protein Content in Breast Milk
3.3. Relationship between Elements in Breast Milk, Passive Smoking, and Seafood Consumption
3.4. Difference between Foremilk and Hind Milk
3.5. ICC Calculation
3.6. Correlation between Each Element and Amount of Fat and Protein
3.7. Limitations
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
- Bravi, F.; Wiens, F.; Decarli, A.; Dal Pont, A.; Agostoni, C.; Ferraroni, M. Impact of Maternal Nutrition on Breast-Milk Composition: A Systematic Review. Am. J. Clin. Nutr. 2016, 104, 646–662. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Ninkina, N.; Kukharsky, M.S.; Hewitt, M.V.; Lysikova, E.A.; Skuratovska, L.N.; Deykin, A.V.; Buchman, V.L. Stem Cells in Human Breast Milk. Hum. Cell 2019, 32, 223–230. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Alsaweed, M.; Hepworth, A.R.; Lefèvre, C.; Hartmann, P.E.; Geddes, D.T.; Hassiotou, F. Human Milk MicroRNA and Total RNA Differ Depending on Milk Fractionation. J. Cell. Biochem. 2015, 116, 2397–2407. [Google Scholar] [CrossRef] [Green Version]
- Kakimoto, R.; Ichiba, M.; Matsumoto, A.; Nakai, K.; Tatsuta, N.; Iwai-Shimada, M.; Ishiyama, M.; Ryuda, N.; Someya, T.; Tokumoto, I.; et al. Variability and Reliability of POP Concentrations in Multiple Breast Milk Samples Collected from the Same Mothers. Environ. Sci. Pollut. Res. 2018, 25, 16309–16315. [Google Scholar] [CrossRef] [PubMed]
- Sun, X.L.; Okamoto, R.; Kido, T.; Honma, S.; Manh, H.D.; Nguyen, H.V.; Anh, L.T.; Phuc, H.D.; Oanh, N.T.P.; Maruzeni, S.; et al. Association of Dioxin in Maternal Breast Milk and Salivary Steroid Hormone Levels in Preschool Children: A Five-Year Follow-up Study of a Vietnam Cohort. Chemosphere 2020, 241, 124899. [Google Scholar] [CrossRef] [PubMed]
- McNamara, P.J.; Abbassi, M. Neonatal Exposure to Drugs in Breast Milk. Pharm. Res. 2004, 21, 555–566. [Google Scholar] [CrossRef]
- Bedi, J.S.; Gill, J.P.S.; Aulakh, R.S.; Kaur, P.; Sharma, A.; Pooni, P.A. Pesticide Residues in Human Breast Milk: Risk Assessment for Infants from Punjab, India. Sci. Total Environ. 2013, 463–464, 720–726. [Google Scholar] [CrossRef]
- Iwai-Shimada, M.; Satoh, H.; Nakai, K.; Tatsuta, N.; Murata, K.; Akagi, H. Methylmercury in the Breast Milk of Japanese Mothers and Lactational Exposure of Their Infants. Chemosphere 2015, 126, 67–72. [Google Scholar] [CrossRef]
- Dórea, J.G.; Fenton, S.E. Estimating Risk of Neurotoxicity from Early Life Exposure: Human Milk Is an Appropriate Matrix, but Messages Should Not Discourage Breastfeeding. Sci. Total Environ. 2019, 693, 133665. [Google Scholar] [CrossRef]
- Li, H.; Li, H.; Li, Y.; Liu, Y.; Zhao, Z. Blood Mercury, Arsenic, Cadmium, and Lead in Children with Autism Spectrum Disorder. Biol. Trace Elem. Res. 2018, 181, 31–37. [Google Scholar] [CrossRef]
- Sasayama, D.; Kuge, R.; Toibana, Y.; Honda, H. Trends in Autism Spectrum Disorder Diagnoses in Japan, 2009 to 2019. JAMA Netw. Open 2021, 4, e219234. [Google Scholar] [CrossRef] [PubMed]
- Rodrigues, J.L.; Nunes, J.A.; Batista, B.L.; Simião de Souza, S.; Barbosa, F., Jr. A Fast Method for the Determination of 16 Elements in Hair Samples by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) with Tetramethylammonium Hydroxide Solubilization at Room Temperature. J. Anal. At. Spectrom. 2008, 23, 992. [Google Scholar] [CrossRef]
- Astolfi, M.L.; Marconi, E.; Protano, C.; Vitali, M.; Schiavi, E.; Mastromarino, P.; Canepari, S. Optimization and Validation of a Fast Digestion Method for the Determination of Major and Trace Elements in Breast Milk by ICP-MS. Anal. Chim. Acta 2018, 1040, 49–62. [Google Scholar] [CrossRef] [PubMed]
- Chao, H.-H.; Guo, C.-H.; Huang, C.-B.; Chen, P.-C.; Li, H.-C.; Hsiung, D.-Y.; Chou, Y.-K. Arsenic, Cadmium, Lead, and Aluminium Concentrations in Human Milk at Early Stages of Lactation. Pediatr. Neonatol. 2014, 55, 127–134. [Google Scholar] [CrossRef]
- Currie, L.A. Detection and Quantification Limits: Origins and Historical Overview. Anal. Chim. Acta 1999, 8, 127–134. [Google Scholar] [CrossRef]
- Hornung, R.W.; Reed, L.D. Estimation of average concentration in the presence of nondetectable values. Appl. Occup. Environ. Hyg. 1990, 5, 46–51. [Google Scholar] [CrossRef]
- Liljequist, D.; Elfving, B.; Skavberg Roaldsen, K. Intraclass Correlation—A Discussion and Demonstration of Basic Features. PLoS ONE 2019, 14, e0219854. [Google Scholar] [CrossRef] [Green Version]
- Koo, T.K.; Li, M.Y. A Guideline of Selecting and Reporting Intraclass Correlation Coefficients for Reliability Research. J. Chiropr. Med. 2016, 15, 155–163. [Google Scholar] [CrossRef] [Green Version]
- Levi, M.; Hjelm, C.; Harari, F.; Vahter, M. ICP-MS Measurement of Toxic and Essential Elements in Human Breast Milk. A Comparison of Alkali Dilution and Acid Digestion Sample Preparation Methods. Clin. Biochem. 2018, 53, 81–87. [Google Scholar] [CrossRef]
- Nakayama, S.F.; Iwai-Shimada, M.; Oguri, T.; Isobe, T.; Takeuchi, A.; Kobayashi, Y.; Michikawa, T.; Yamazaki, S.; Nitta, H.; Kawamoto, T. Blood Mercury, Lead, Cadmium, Manganese and Selenium Levels in Pregnant Women and Their Determinants: The Japan Environment and Children’s Study (JECS). J. Expo. Sci. Environ. Epidemiol. 2019, 29, 633–647. [Google Scholar] [CrossRef] [Green Version]
- Dubascoux, S.; Andrey, D.; Vigo, M.; Kastenmayer, P.; Poitevin, E. Validation of a Dilute and Shoot Method for Quantification of 12 Elements by Inductively Coupled Plasma Tandem Mass Spectrometry in Human Milk and in Cow Milk Preparations. J. Trace Elem. Med. Biol. 2018, 49, 19–26. [Google Scholar] [CrossRef]
- Bastos, W.R.; Vieira, S.M.; Manzatto, Â.G.; Dórea, J.G.; Rubira, M.C.; de Souza, V.F.P.; da Costa Junior, W.A.; Souza Bastos, M.T. Heterogeneity of Multimedia Exposures to Neurotoxic Elements (Al, As, Cd, Pb, Mn, and Hg) in Breastfed Infants from Porto Velho, Brazil. Biol. Trace Elem. Res. 2018, 184, 7–15. [Google Scholar] [CrossRef] [PubMed]
- Vollset, M.; Iszatt, N.; Enger, Ø.; Gjengedal, E.L.F.; Eggesbø, M. Concentration of Mercury, Cadmium, and Lead in Breast Milk from Norwegian Mothers: Association with Dietary Habits, Amalgam and Other Factors. Sci. Total Environ. 2019, 677, 466–473. [Google Scholar] [CrossRef] [PubMed]
- Islam, M.R.; Attia, J.; Alauddin, M.; McEvoy, M.; McElduff, P.; Slater, C.; Islam, M.M.; Akhter, A.; d’Este, C.; Peel, R.; et al. Availability of Arsenic in Human Milk in Women and Its Correlation with Arsenic in Urine of Breastfed Children Living in Arsenic Contaminated Areas in Bangladesh. Environ. Health 2014, 13, 101. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Luvonga, C.; Rimmer, C.A.; Yu, L.L.; Lee, S.B. Organoarsenicals in Seafood: Occurrence, Dietary Exposure, Toxicity, and Risk Assessment Considerations—A Review. J. Agric. Food Chem. 2020, 68, 943–960. [Google Scholar] [CrossRef]
- Fängström, B.; Moore, S.; Nermell, B.; Kuenstl, L.; Goessler, W.; Grandér, M.; Kabir, I.; Palm, B.; Arifeen, S.E.; Vahter, M. Breast-Feeding Protects against Arsenic Exposure in Bangladeshi Infants. Environ. Health Perspect. 2008, 116, 963–969. [Google Scholar] [CrossRef] [Green Version]
- Ballard, O.; Morrow, A.L. Human Milk Composition. Pediatr. Clin. N. Am. 2013, 60, 49–74. [Google Scholar] [CrossRef] [Green Version]
- Sobolev, N.; Aksenov, A.; Sorokina, T.; Chashchin, V.; Ellingsen, D.G.; Nieboer, E.; Varakina, Y.; Plakhina, E.; Onuchina, A.; Thomassen, M.S.; et al. Iodine and Bromine in Fish Consumed by Indigenous Peoples of the Russian Arctic. Sci. Rep. 2020, 10, 5451. [Google Scholar] [CrossRef]
- van Sadelhoff, J.; Mastorakou, D.; Weenen, H.; Stahl, B.; Garssen, J.; Hartog, A. Short Communication: Differences in Levels of Free Amino Acids and Total Protein in Human Foremilk and Hindmilk. Nutrients 2018, 10, 1828. [Google Scholar] [CrossRef] [Green Version]
- Italianer, M.F.; Naninck, E.F.G.; Roelants, J.A.; van der Horst, G.T.J.; Reiss, I.K.M.; van Goudoever, J.B.; Joosten, K.F.M.; Chaves, I.; Vermeulen, M.J. Circadian Variation in Human Milk Composition, a Systematic Review. Nutrients 2020, 12, 2328. [Google Scholar] [CrossRef]
- Vezzoli, G.; Baragetti, I.; Zerbi, S.; Caumo, A.; Soldati, L.; Bellinzoni, P.; Centemero, A.; Rubinacci, A.; Moro, G.; Bianchi, G. Strontium Absorption and Excretion in Normocalciuric Subjects: Relation To calcium Metabolism. Clin. Chem. 1998, 44, 586–590. [Google Scholar] [CrossRef] [PubMed]
- McCall, A.S.; Cummings, C.F.; Bhave, G.; Vanacore, R.; Page-McCaw, A.; Hudson, B.G. Bromine Is an Essential Trace Element for Assembly of Collagen IV Scaffolds in Tissue Development and Architecture. Cell 2014, 157, 1380–1392. [Google Scholar] [CrossRef] [Green Version]
- He, C.; Song, W.; Weston, T.A.; Tran, C.; Kurtz, I.; Zuckerman, J.E.; Guagliardo, P.; Miner, J.H.; Ivanov, S.V.; Bougoure, J.; et al. Peroxidasin-Mediated Bromine Enrichment of Basement Membranes. Proc. Natl. Acad. Sci. USA 2020, 117, 15827–15836. [Google Scholar] [CrossRef] [PubMed]
- Kikuchi, Y.; Nomiyama, T.; Kumagai, N.; Uemura, T.; Omae, K. Cadmium Concentration in Current Japanese Foods and Beverages. J. Occup. Health 2002, 44, 240–247. [Google Scholar] [CrossRef] [Green Version]
- Bolann, B.J.; Ulvik, R.J. Release of Iron from Ferritin by Xanthine Oxidase. Role of the Superoxide Radical. Biochem. J. 1987, 243, 55–59. [Google Scholar] [CrossRef] [Green Version]
- Chesley, R.F.; Annitto, J.E. Evaluation of molybdenized ferrous sulfate in the treatment of hypochromic anemia of pregnancy. Bull. Jersey City Margaret Hague Mat. Hosp. 1948, 1, 68–75. [Google Scholar] [PubMed]
- Kippler, M.; Goessler, W.; Nermell, B.; Ekström, E.C.; Lönnerdal, B.; El Arifeen, S.; Vahter, M. Factors Influencing Intestinal Cadmium Uptake in Pregnant Bangladeshi Women—A Prospective Cohort Study. Environ. Res. 2009, 109, 914–921. [Google Scholar] [CrossRef] [PubMed]
- Margrete Meltzer, H.; Lise Brantsæter, A.; Borch-Iohnsen, B.; Ellingsen, D.G.; Alexander, J.; Thomassen, Y.; Stigum, H.; Ydersbond, T.A. Low Iron Stores Are Related to Higher Blood Concentrations of Manganese, Cobalt and Cadmium in Non-Smoking, Norwegian Women in the HUNT 2 Study. Environ. Res. 2010, 110, 497–504. [Google Scholar] [CrossRef]
- Park, J.-H.; Park, S.; Kim, Y. Iron Deficiency Is Not Associated with Increased Blood Cadmium in Infants. Ann. Occup. Environ. Med. 2014, 26, 3. [Google Scholar] [CrossRef] [Green Version]
- Motas, M.; Jiménez, S.; Oliva, J.; Cámara, M.Á.; Pérez-Cárceles, M.D. Heavy Metals and Trace Elements in Human Breast Milk from Industrial/Mining and Agricultural Zones of Southeastern Spain. Int. J. Environ. Res. Public Health 2021, 18, 9289. [Google Scholar] [CrossRef]
Mean ± SD | Median | IQR | % | |
---|---|---|---|---|
Mother | ||||
Maternal age | 33.1 ± 3.6 | |||
Pre-pregnancy BMI | 21.7 ± 2.9 | |||
Passive smoking (%, Yes) | 36.4% | |||
Seafood consumption (g/day) | 7.5 | 5.6 | ||
Child | ||||
Child sex (%, male) | 63.6% | |||
Child’s age in months | ||||
3 months | 36.4% | |||
4 months | 45.5% | |||
5 months | 18.2% | |||
Birth weight (g) | 3045 ± 313.9 |
Linearity (R2) | MDL (ng/mL) | MQL (ng/mL) | |
---|---|---|---|
Li | 0.9999 | 0.054 | 0.140 |
Be | 0.9999 | 0.0082 | 0.021 |
Mg | 0.9998 | 31 | 79 |
Ca | 0.9998 | 318 | 818 |
V | 0.9998 | 0.068 | 0.174 |
Mn | 0.9999 | 0.24 | 0.62 |
Fe | 1.0000 | 65 | 168 |
Co | 0.9998 | 0.039 | 0.10 |
Ni | 0.9998 | 0.96 | 2.5 |
Cu | 1.0000 | 1.3 | 3.4 |
Zn | 1.0000 | 1.5 | 3.8 |
Ga | 0.9994 | 0.11 | 0.19 |
As | 0.9999 | 0.071 | 0.18 |
Se | 0.9996 | 0.43 | 1.1 |
Br | 1.0000 | 1.7 | 4.4 |
Rb | 0.9999 | 0.28 | 0.71 |
Sr | 0.9999 | 0.061 | 0.16 |
Mo | 0.9999 | 0.12 | 0.31 |
Ag | 0.9999 | 0.023 | 0.059 |
Cd | 0.9997 | 0.094 | 0.24 |
Sb | 1.0000 | 0.049 | 0.13 |
Cs | 0.9998 | 0.11 | 0.29 |
Ba | 0.9999 | 0.052 | 0.13 |
W | 0.9999 | 0.054 | 0.14 |
Hg | 1.0000 | 0.040 | 0.10 |
Pb | 1.0000 | 0.078 | 0.20 |
U | 1.0000 | 0.019 | 0.049 |
Our Study | Company A | Published Paper | ||||
---|---|---|---|---|---|---|
Certified Value (ng/g) (Acceptable Range) | Mean a (ng/g) | RSD (%) | Mean b (ng/g) | RSD (%) | Median (ng/g) | |
Li | 3.0 | 1.7 | 2.55 | 1.2 | ||
Be | 0.014 | 17 | <0.041 | |||
Mg | 32,400 (32,200−32,600) | 34,900 | 3.4 | 32,400 | 2.3 | 35,000 |
Ca | 257,000 (255,000−259,000) | 258,000 | 1.9 | 248,000 | 1.5 | 257,000 |
V | 0.23 | 5.1 | 0.201 | 17 | ||
Mn | 40 (38−42) | 64 | 2.0 | 51.3 | 2.7 | 60.5 |
Fe | 194 (187−201) | 226 | 1.7 | 198 | 3.3 | 205 |
Co | 0.085 | 14 | 0.089 | 0.071 | ||
Ni | 2.39 | 10 | 1.54 | 8.9 | ||
Cu | 268 (265−271) | 269 | 1.7 | 264 | 2.6 | 284 |
Zn | 2226 | 1.4 | 1950 | 3.3 | 2637 | |
Ga | 1.6 | 0.3 | 0.0138 | 152 | ||
As | 0.23 | 5.0 | <0.32 | |||
Se | 16 | 6.6 | 14.6 | 2.9 | 17.3 | |
Br | 1642 | 1.7 | 1300 | 3.4 | ||
Rb | 464 | 1.0 | 470 | 472 | ||
Sr | 49 | 0.4 | 48 | 46.9 | ||
Mo | 2.1 | 0.3 | 2.1 | 2.21 | <PLOQ | |
Ag | 0.054 | 10 | 0.084 | 0.105 | ||
Cd | 0.063 | 23 | 0.054 | 0.0285 | ||
Sb | <0.049 | <0.065 | ||||
Cs | 2.2 | 8.7 | 1.7 | 1.71 | ||
Ba | 13 | 2.0 | 11 | 10.7 | ||
W | <0.054 | 0.2 | 0.248 | |||
Hg | 0.101 (0.068−0.134) | 0.112 | 7.6 | 0.094 | 0.101 | |
Pb | 0.44 | 12 | 0.29 | 0.318 | ||
U | < 0.019 |
MDL (ng/mL) | Detection (N) | Min (ng/g) | P5 (ng/g) | Median (ng/g) | P95 (ng/g) | Max (ng/g) | |
---|---|---|---|---|---|---|---|
Li | 0.054 | 97 | <0.054 | <0.054 | 0.10 | 0.26 | 0.47 |
Be | 0.0082 | 22 | <0.0082 | <0.0082 | <0.0082 | 0.013 | 0.027 |
Mg | 31 | 132 | 27,007 | 28,438 | 34,015 | 43,151 | 45,204 |
Ca | 318 | 132 | 199,161 | 210,063 | 306,797 | 360,005 | 397,557 |
V | 0.068 | 51 | <0.068 | <0.068 | <0.068 | 0.14 | 0.45 |
Mn | 0.24 | 132 | 1.5 | 1.6 | 3.1 | 7.4 | 10 |
Fe | 65 | 132 | 70 | 96 | 234 | 543 | 657 |
Co | 0.039 | 116 | <0.039 | <0.039 | 0.062 | 0.15 | 0.73 |
Ni | 0.96 | 132 | 1.6 | 2.5 | 3.8 | 12 | 38 |
Cu | 1.3 | 132 | 73 | 90 | 246 | 392 | 493 |
Zn | 1.5 | 132 | 376 | 538 | 1011 | 2235 | 2496 |
As | 0.071 | 132 | 0.48 | 0.62 | 1.3 | 7.2 | 24 |
Se | 0.43 | 132 | 12 | 12 | 16 | 22 | 27 |
Br | 1.7 | 132 | 665 | 742 | 1039 | 1493 | 1723 |
Rb | 0.28 | 132 | 345 | 361 | 439 | 553 | 609 |
Sr | 0.061 | 132 | 22 | 27 | 42 | 97 | 117 |
Mo | 0.12 | 132 | 0.18 | 0.39 | 1.5 | 6.3 | 12 |
Ag | 0.023 | 90 | <0.023 | <0.023 | 0.057 | 0.44 | 0.57 |
Cd | 0.094 | 132 | 0.11 | 0.13 | 0.20 | 0.35 | 0.42 |
Sb | 0.049 | 86 | <0.049 | <0.049 | 0.063 | 0.17 | 0.43 |
Cs | 0.11 | 132 | 0.8 | 0.9 | 1.4 | 3.1 | 8.1 |
Ba | 0.052 | 132 | 0.4 | 0.6 | 1.7 | 6.5 | 27 |
W | 0.054 | 1 | <0.054 | <0.054 | <0.054 | <0.054 | 4.6 |
Hg | 0.040 | 132 | 0.06 | 0.1 | 0.57 | 1.4 | 2.1 |
Pb | 0.078 | 89 | <0.078 | <0.078 | 0.11 | 0.57 | 45 |
U | 0.019 | 0 | <0.019 | <0.019 | <0.019 | <0.019 | <0.019 |
Min | P5 | Median | P95 | Max | |
---|---|---|---|---|---|
Fat (g/L) | 16 | 22 | 53 | 108 | 123 |
Calorie (kcal/mL) | 519 | 558 | 850 | 1362 | 1510 |
Protein (mg/mL) | 5.6 | 6.1 | 7.9 | 11 | 12 |
Foremilk (N = 66) | Hindmilk (N = 66) | ||||
---|---|---|---|---|---|
Median | IQR | Median | IQR | Paired t-Test | |
(ng/g) | (ng/g) | (ng/g) | (ng/g) | (p-Value) | |
Li | 0.1 | 0.14 | 0.097 | 0.091 | |
Be | <0.0082 | <0.0082 | NA | ||
Mg | 33,917 | 6251 | 34,206 | 6345 | |
Ca | 304,659 | 64,672 | 309,864 | 69,771 | |
V | <0.068 | <0.068 | NA | ||
Mn | 2.8 | 1.4 | 3.5 | 2.2 | <0.001 |
Fe | 162 | 91 | 314 | 194 | <0.001 |
Co | 0.059 | 0.031 | 0.067 | 0.043 | |
Ni | 4 | 3.5 | 3.8 | 2.4 | |
Cu | 235 | 110 | 266 | 110 | <0.001 |
Zn | 1027 | 520 | 1005 | 555 | |
As | 1.1 | 0.73 | 1.6 | 1.6 | <0.001 |
Se | 15 | 3.8 | 16 | 4.9 | <0.001 |
Br | 1021 | 351 | 1064 | 356 | |
Rb | 443 | 89 | 438 | 84 | |
Sr | 41 | 27 | 43 | 29 | |
Mo | 1 | 1.1 | 2.1 | 1.5 | <0.001 |
Ag | 0.049 | 0.1 | 0.06 | 0.1 | |
Cd | 0.17 | 0.065 | 0.23 | 0.079 | <0.001 |
Sb | 0.062 | 0.05 | 0.064 | 0.037 | |
Cs | 1.5 | 0.55 | 1.4 | 0.55 | |
Ba | 1.6 | 2.1 | 1.8 | 2 | |
W | <0.054 | <0.054 | NA | ||
Hg | 0.47 | 0.46 | 0.63 | 0.59 | <0.001 |
Pb | 0.11 | 0.11 | 0.1 | 0.062 | |
U | <0.019 | <0.019 | NA |
Foremilk (N = 66) | Hindmilk (N = 66) | ||||
---|---|---|---|---|---|
Median | IQR | Median | IQR | Paired t-Test | |
(p-Value) | |||||
Fat (g/L) | 43 | 21 | 66 | 33 | <0.001 |
Protein (mg/mL) | 7.6 | 2.1 | 8.4 | 2.1 | <0.001 |
ICC (A,1) | ||||
---|---|---|---|---|
Intra-Day | Inter-Day | |||
Foremilk | Hindmilk | Foremilk | Hindmilk | |
Mg | 0.69 | 0.46 | 0.81 | 0.70 |
Ca | 0.82 | 0.90 | 0.92 | 0.83 |
Mn | 0.44 | 0.57 | 0.42 | 0.80 |
Fe | 0.38 | 0.59 | 0.10 | 0.38 |
Co | 0.030 | 0.51 | 0.17 | 0.18 |
Ni | 0.00 | 0.25 | 0.033 | 0.04 |
Cu | 0.88 | 0.87 | 0.89 | 0.90 |
Zn | 0.83 | 0.76 | 0.91 | 0.86 |
As | 0.69 | 0.83 | 0.18 | 0.33 |
Se | 0.61 | 0.64 | 0.55 | 0.67 |
Br | 0.82 | 0.68 | 0.88 | 0.86 |
Rb | 0.83 | 0.86 | 0.89 | 0.75 |
Sr | 0.95 | 0.95 | 0.97 | 0.95 |
Mo | 0.73 | 0.87 | 0.63 | 0.81 |
Cd | 0.42 | 0.58 | 0.36 | 0.25 |
Cs | 0.56 | 0.78 | 0.63 | 0.51 |
Ba | 0.77 | 0.70 | 0.74 | 0.52 |
Fat | 0.17 | 0.029 | 0.33 | 0.38 |
Protein | 0.76 | 0.76 | 0.69 | 0.73 |
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Iwai, K.; Iwai-Shimada, M.; Asato, K.; Nakai, K.; Kobayashi, Y.; Nakayama, S.F.; Tatsuta, N. Intra- and Inter-Day Element Variability in Human Breast Milk: Pilot Study. Toxics 2022, 10, 109. https://doi.org/10.3390/toxics10030109
Iwai K, Iwai-Shimada M, Asato K, Nakai K, Kobayashi Y, Nakayama SF, Tatsuta N. Intra- and Inter-Day Element Variability in Human Breast Milk: Pilot Study. Toxics. 2022; 10(3):109. https://doi.org/10.3390/toxics10030109
Chicago/Turabian StyleIwai, Kenta, Miyuki Iwai-Shimada, Kaname Asato, Kunihiko Nakai, Yayoi Kobayashi, Shoji F. Nakayama, and Nozomi Tatsuta. 2022. "Intra- and Inter-Day Element Variability in Human Breast Milk: Pilot Study" Toxics 10, no. 3: 109. https://doi.org/10.3390/toxics10030109