Chitinase digestion for the analysis of microplastics in chitinaceous organisms using the terrestrial isopod Oniscus asellus L. as a model organism

Chitinaceous organisms have been found to ingest microplastic; however, a standardised, validated, and time- and cost-efficient method for dissolving these organisms without affecting microplastic particles is still required. This study tested four protocols for dissolving organisms with a chitin exoskeleton: 1) potassium hydroxide (KOH) + chitinase, 2) Creon® + chitinase, 3) hydrogen peroxide (H2O2) + chitinase, and, 4) Nitric Acid (HNO3) + hydrogen peroxide (H2O2). The effects on microplastics composed of eight different polymers were also tested. The use of H2O2 followed by chitinase was found to be a highly efficient method. The three other protocols either did not digest the chitin sufficiently or negatively affected the tested polymers. A recovery test using microplastic fibres, beads and tyre particles revealed high recovery rates of 0.85, 0.89 and 1 respectively. This further supported the applicability of the H2O2 and chitinase (protocol 3) for dissolving chitinaceous organisms. Thus, we recommend that future investigations of microplastic (0.05 μm–5000 μm) in chitinaceous organisms (0.3 cm–5 cm) utilise the here presented methodology. This represents an important component of the ongoing validation and harmonization of methodological approaches that are urgently needed for the advancement of microplastic assessments globally.publishedVersio

The Iowa Homemaker vol.23, no.4

Keeping Up With Today, Margaret Ralston, page 2 Dear Homemaker Staff, Mable Jennings, page 3 Our Summer Fellowships, Victoria McKibben, page 4 Pan American Menus, Marian Loofe, page 6 Accent On Accessories, Frances Madigan, page 7 What’s New in Home Economics, Lily Houseman, page 8 Designed by Iowa Coeds, Helen Horton, page 10 Across Alumnae Desks, Virginia Carter, page 12 Alums in the News, Rachel Ann Lusher, page 1

The Iowa Homemaker vol.23, no.8

Keeping Up With Today, Margaret Ralston, page 2 Honored for Service, page 3 From Graduates’ Letters, page 4 G. I. Candy Bar, Ruth Midgorden, page 5 When You’re Career-Bound, Genevieve Callahan, page 6 Educational Psychology in Action, Victoria McKibben, page 7 Research Introduces New Meat, Norma Dale, page 8 Spotlight on a SPAR, page 9 What’s New in Home Economics, page 10 Forecast Clothing Prospects, Dorothy Watt, page 12 The Most From The Least, page 13 Investigate Home Canning, Frances Kerekes, page 14 Wartime Tips for Wise Shoe Care, Janet Russell, page 16 Clothing Survey, Doris Ann Gregg, page 17 Across Alumnae Desks, Virginia Carter, page 18 Alums in the News, Rachel Lusher, page 2

Patterns of microparticles in blank samples: A study to inform best practices for microplastic analysis.

Quality assurance and quality control (QA/QC) techniques are critical to analytical chemistry, and thus the analysis of microplastics. Procedural blanks are a key component of QA/QC for quantifying and characterizing background contamination. Although procedural blanks are becoming increasingly common in microplastics research, how researchers acquire a blank and report and/or use blank contamination data varies. Here, we use the results of laboratory procedural blanks from a method evaluation study to inform QA/QC procedures for microplastics quantification and characterization. Suspected microplastic contamination in the procedural blanks, collected by 12 participating laboratories, had between 7 and 511 particles, with a mean of 80 particles per sample (±SD 134). The most common color and morphology reported were black fibers, and the most common size fraction reported was 20-212 μm. The lack of even smaller particles is likely due to limits of detection versus lack of contamination, as very few labs reported particles <20 μm. Participating labs used a range of QA/QC techniques, including air filtration, filtered water, and working in contained/enclosed environments. Our analyses showed that these procedures did not significantly affect blank contamination. To inform blank subtraction, several subtraction methods were tested. No clear pattern based on total recovery was observed. Despite our results, we recommend commonly accepted procedures such as thorough training and cleaning procedures, air filtration, filtered water (e.g., MilliQ, deionized or reverse osmosis), non-synthetic clothing policies and enclosed air flow systems (e.g., clean cabinet). We also recommend blank subtracting by a combination of particle characteristics (color, morphology and size fraction), as it likely provides final microplastic particle characteristics that are most representative of the sample. Further work should be done to assess other QA/QC parameters, such as the use of other types of blanks (e.g., field blanks, matrix blanks) and limits of detection and quantification

Innovative reference materials for method validation in microplastic analysis including interlaboratory comparison exercises

Reference materials (RMs) are vital tools in the validation of methods used to detect environmental pollutants. Microplastics, a relatively new environmental pollutant, require a variety of complex approaches to address their presence in environmental samples. Both interlaboratory comparison (ILC) studies and RMs are essential to support the validation of methods used in microplastic analysis. Presented here are results of quality assurance and quality control (QA/QC) performed on two types of candidate microplastic RMs: dissolvable gelatin capsules and soda tablets. These RMs have been used to support numerous international ILC studies in recent years (2019–2022). Dissolvable capsules containing polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene (PE), and polystyrene (PS), in different size fractions from 50 to 1000 µm, were produced for one ILC study, obtaining relative standard deviation (RSD) from 0 to 24%. The larger size fraction allowed for manual addition of particles to the capsules, yielding 0% error and 100% recovery during QA/QC. Dissolvable capsules were replaced by soda tablets in subsequent ILC studies and recovery test exercises because they were found to be a more reliable carrier for microplastic RMs. Batches of soda tablets were produced containing different single and multiple polymer mixtures, i.e., PE, PET, PS, PVC, polypropylene (PP), and polycarbonate (PC), with RSD ranging from 8 to 21%. Lastly, soda tablets consisting of a mixture of PE, PVC, and PS (125–355 µm) were produced and used for recovery testing during pretreatment of environmental samples. These had an RSD of 9%. Results showed that soda tablets and capsules containing microplastics >50 µm could be produced with sufficient precision for internal recovery tests and external ILC studies. Further work is required to optimize this method for smaller microplastics (< 50 µm) because variation was found to be too large during QA/QC. Nevertheless, this approach represents a valuable solution addressing many of the challenges associated with validating microplastic analytical methods.publishedVersio

The Iowa Homemaker vol.23, no.3

Keeping Up With Today, Margaret Ralston, page 2 Note to Freshmen, A Senior, page 3 Trained for Action, Lois Stewart, page 4 Your College Primer, Marjorie Beneke, page 5 No Stamps Required, Margaret Honz, page 6 Engineering Cadettes Reporting, Doris Ann Gregg, page 7 Rooms with Personality, Margaret Ralston, page 8 Surveying Plastics, Janet Russell, page 9 Vicky’s Wardrobe, Patricia Hayes, page 10 What’s New in Home Economics, Lily Houseman, page 12 It’s Mail Time, Beth Rocke, page 15 YWCA On Review, Frances Kerekes, page 16 Ranked As Leaders, Victoria McKibben, page 17 Overseas Duty Assignment, Marian Loofe, page 18 Across Alumnae Desks, Virginia Carter, 20 Alums in the News, Rachel Ann Lusher, page 2

The Iowa Homemaker vol.23, no.1

For Wartime Beauty, Virginia Bates, page 4 Keeping Up With Today, Margaret Ralston, page 5 Women in Service Dress for Duty, Norma Dale, page 6 New Navy Kitchen Serves, Helen Hudson, page 7 Women as Food Inspectors, Dorothy Watt, page 8 Pioneering Textile Fibers, Ruth Herzig, page 9 Egg-Drying Increases Production, Helen James, page 10 Letter from a WAAC, Marjorie P. Hinkle, page 11 What’s New in Home Economics, Lily Houseman, page 12 Vicky Heralds Spring, Pat Hayes, page 14 Women Choose Engineering Careers, Frances Madigan, page 15 Campus Notions Dept., Joan Miller, page 16 For Today’s Bride, Grace Brown, page 18 Herbs Inspire Variety, Margaret Ralston, page 20 Across Alumnae Desks, Virginia Carter, page 22 Alums in the News, Rachel Ann Lusher, page 2

The Iowa Homemaker vol.23, no.5

Moire, Keith Shillington, page 2 Keeping Up With Today, Margaret Ralston, page 3 Christmas Suggestions, Pfc. Schwanz, AS Greenburg, page 4 Navy Menus on Review, Eileen Cooper, page 6 Creating the Holiday Spirit, Joan Miller, page 7 For Christmas I’d Like, Betty Aldrich, page 8 For Use – Peanut Substitutes, Norma Dale, page 10 Wartime Cards Marked by Individuality, Julie Johnston, page 11 What’s New in Home Economics, Lily Houseman, page 12 Iowa Staters Go Caroling, Frances Kerekes, page 16 For the Christmas Stocking¸ Lois Stewart, page 17 European Rationing, Catherine Tidemanson, page 18 Supervise Army Hospital Diets, Virginia Brainard, page 19 Originality Expressed in Festive Wrappings, Doris Gregg, page 20 Across Alumnae Desks, Virginia Carter, page 22 Alums in the News, Rachel Ann Lusher, page 2

The Iowa Homemaker vol.23, no.7

Keeping Up With Today, Margaret Ralston, page 2 Lunch Program Expands, Doris Ann Gregg, page 3 Plan for Post-War Service, Patricia O’Connell, page 4 Medicine from Mold, Helen James, page 5 Home Front Organizers, Mary Elizabeth Lush, page 6 Graduates Report by Mail, Dorothy Drown, page 7 What’s New in Home Economics, Lily Houseman, page 8 Good Posture Makes Good Sense, Lila Mae Hummel, page 10 Child Training, Doris Rystrom and Jane Gardner, page 11 Your Best Foot Forward, Jean Miller, page 12 A Housemaking Teacher Talks Shop, Betty A. Brady, page 13 Wartime Decision, Doris Gugeler, page 14 Alums in the News, Rachel Ann Lusher, page 15 Across Alumnae Desks, Virginia Carter, page 1

The Iowa Homemaker vol.23, no.2

Presenting 1943 Veishea, Dorothy Walker, page 1 Keeping Up With Today, Margaret Ralston, page 4 Letter from a SPAR, Mary Leffler, page 5 Demand for Day Nurseries, Marjory Gillingham, page 6 Freezing Preserves Victory Foods, Frances Madigan, page 7 Gardens Challenge Faculty, Lois Stewart, page 8 Food Affects Morale, Dr. Lowell Selling, page 9 Vicky Favors Simplicity, Mary Lou Springer, page 10 An Economist Interprets Food Problems, Dorothy Conquest, page 11 Grooming for a Career, Mary Schmidt, page 12 Students Enlist, Annette DeLay, page 13 The Red Cross Canteen Corps Mobilize, page 14 What’s New in Home Economics, Lily Houseman, page 16 Women to Know, Josephine Ahern, page 18 Home Economists Plan for the WAAC, Frances Kerekes, page 19 Canada Organizes for Nutrition, Mary Ellen Sullivan, page 20 Experience Gleaned, Janet Russell, page 22 Eggs Spell Good Nutrition, Marian Loofe, page 23 Commissioned in Dietetics, Victoria McKibben, page 24 Across Alumnae Desks, Virginia Carter, page 26 Whole Grains Fortify, Shirley Like, page 28 Designed for Art Majors, JoAnne Nicholson, page 29 Alums in the News, Rachel Ann Lusher, page 31 Meals on the Move, Catherine Tidemanson, page 3