Dry Ashing Research Articles

Determination Ca, Cu, Fe, Mn, and Zn release from food in simple gastrointestinal extraction test

In this study, by conducting simulated in vitro digestion experiments on samples, the extraction rates of several essential metal elements in some common food ingredients were determined to guide a rational and balanced diet. At the same time, taking vegetables as an example, the research investigated the impact of food preprocessing on the extraction rates of metal elements within them, demonstrating that the influence of heat treatment varies for different element extraction rates. A wet digestion system using nitric acid-hydrogen peroxide was established for seafood and vegetable samples, and an analytical method for determining Ca, Cu, Fe, Mn and Zn using inductively coupled plasma optical emission spectrometry (ICP-OES) was developed. The detection limits of the method ranged from 0.0003 mg L−1 to 0.1567 mg L−1, with RSDs between 0.004% and 7.161%. The measured contents of several important metal elements in standard substances were largely consistent with national standards, confirming the accuracy and precision of the method. Based on wet digestion, the contents of various metal elements in simulated digestive fluids were determined. The detection limits for the simulated digestion method ranged from 0.0005 mg L−1 to 0.0077 mg L−1, with RSDs between 0.001% and 8.839%, verifying the precision of the method. Consequently, the extraction rates of metal elements in the two types of samples were obtained, leading to the conclusion that vegetable samples are more easily digested compared to seafood, releasing their metal elements. Moreover, the extraction rates of different elements vary within the same type of sample, and the extraction rates of the same element also differ across different samples. For dried fruit samples, a dry ashing digestion system was established, and an analytical method for determining Ca, Cu, Fe, Mn and Zn using ICP was developed. The detection limits of this method ranged from 0.0003 mg L−1 to 0.0073 mg L−1, with RSDs between 0.001% and 1.076%, and the spiked recovery rates were between 85.43% and 105.96%, confirming the accuracy and precision of the method. Based on dry ashing digestion, the contents of various metal elements in simulated digestive fluids were measured, which led to the determination of the element extraction rates. Among these, the extraction rates for Ca, Cu, and Mn were relatively high.

#2651 Microwave tissue digestion and flame atomic absorption spectroscopy for measuring tissue sodium content in CKD patients

Abstract Background and Aims Skin and muscle sodium accumulation has been demonstrated in CKD patients and may contribute to progression of the disease. Various methods are available for measuring tissue sodium content. However, the accuracy and reproducibility of these methods remain unknown. Dry ashing is the most used digestion method, but is expensive, time consuming and has a risk of incomplete digestion. This study compared microwave digestion, dry ashing, and two electrolyte quantification methods for quantifying tissue sodium and potassium. Method We compared microwave digestion (Ethos LEAN Compact Microwave Digestion System, Milestone SRL) and dry ashing (Nabertherm S27) as sample preparation methods, and flame atomic absorption spectroscopy (FAAS, Model 425 Flame Photometer, Sherwood Scientific) and inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 720-ES, Varian Inc.) as electrolyte quantification methods. Skin and muscle samples were obtained from rats and mice, and human skin samples were used. Tissues biopsies were cut in three pieces and digested separately. The methods were compared using interclass correlation coefficient (ICC) and Bland-Altman analysis. The third piece of tissue was microwave-digested by another operator to test inter-operator reproducibility by calculating the ICC and absolute overall mean difference. Results With microwave digestion and FAAS median (IQR) human skin concentration was 114.8 (99.2-157.0, n = 12) mmol/L, confirming tissue sodium storage. When including all tissues, FAAS and ICP-OES showed high agreement for sodium (ICC 0.98, bias –0.00008 mmol/g, n = 141 and potassium (ICC 0.98, bias –0.005 mmol/g, n = 141). Microwave digestion and ashing showed agreement for sodium (ICC 0.93, bias –0.002 mmol/g, n = 61) and potassium (ICC 0.93, bias –0.02 mmol/g, n = 61). The inter-operator agreement was good for sodium (ICC 0.95, absolute mean difference (SD) 0.044 mmol/g (0.073), n = 70) and potassium (ICC 0.96, absolute mean difference (SD) 0.031 mmol/g (0.032), n = 70). Conclusion Microwave digestion with FAAS is a reliable and consistent method for sodium and potassium trace analysis in animal and human tissues compared to ashing and ICP-OES, respectively. This method showed more quantification of cations than the most frequently reported method, representing an easier, and less time-consuming way to quantify tissue sodium in CKD research.

Development of a Method to Measure Trace Levels of Uranium and Thorium in Scintillation Films

Abstract We have established a method to measure picograms-per-gram (pg g−1) levels of 238U and 232Th in scintillation films by combining the dry ashing method and inductively coupled plasma mass spectrometry. Trace amounts of 238U and 232Th were measured in up to 2 g of scintillation film with almost 100% collection efficiency. This paper details the experimental procedure, including the pretreatment of the samples and labware, detection limit of the method, collection efficiencies of 238U and 232Th, and measurement of 238U and 232Th in a polyethylene naphthalate film. This method is also applicable to 238U and 232Th measurements in other low-background organic materials for rare-event search experiments.

MICROWAVE TISSUE DIGESTION AND FLAME ATOMIC ABSORPTION SPECTROSCOPY FOR MEASURING TISSUE SODIUM CONTENT IN HYPERTENSIVE AND CARDIOVASCULAR RISK PATIENTS

Objective: Skin sodium accumulation has been demonstrated in hypertensive patients and may contribute to the pathophysiology of hypertension. Various methods are available for measuring tissue sodium content. However, the accuracy and reproducibility of these methods remain unknown. Dry ashing is the most used digestion method, but is expensive, time consuming and has a risk of incomplete digestion. This study compared microwave digestion, dry ashing, and two electrolyte quantification methods for quantifying tissue sodium and potassium. Design and method: We compared microwave digestion (Ethos LEAN Compact Microwave Digestion System, Milestone SRL) and dry ashing (Nabertherm S27) as sample preparation methods, and flame atomic absorption spectroscopy (FAAS, Model 425 Flame Photometer, Sherwood Scientific) and inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 720-ES, Varian Inc.) as electrolyte quantification methods. Skin and muscle samples were obtained from rats and mice, and human skin samples were used. Tissues biopsies were cut in three pieces and digested separately. The methods were compared using interclass correlation coefficient (ICC) and Bland-Altman analysis. The third piece of tissue was microwave-digested by another operator to test inter-operator reproducibility by calculating the ICC and absolute overall mean difference. Results: With microwave digestion and FAAS median (IQR) human skin concentration was 114.8 (99.2-157.0, n=12) mmol/L, confirming tissue sodium storage. When including all tissues, FAAS and ICP-OES showed high agreement for sodium (ICC 0.98, bias -0.00008 mmol/g, n=141 and potassium (ICC 0.98, bias -0.005 mmol/g, n=141). Microwave digestion and ashing showed agreement for sodium (ICC 0.93, bias -0.002 mmol/g, n=61) and potassium (ICC 0.93, bias -0.02 mmol/g, n=61). The inter-operator agreement was good for sodium (ICC 0.95, absolute mean difference (SD) 0.044 mmol/g (0.073), n=70) and potassium (ICC 0.96, absolute mean difference (SD) 0.031 mmol/g (0.032), n=70). Conclusions: Microwave digestion with FAAS is a reliable and consistent method for sodium and potassium trace analysis in animal and human tissues compared to ashing and ICP-OES, respectively. This method showed more quantification of cations than the most frequently reported method, representing an easier, and less time-consuming way to quantify tissue sodium in hypertension and cardiovascular research.

Rapid and Complete Digestion of Refractory Geological Samples Using Ultrafine Powder for Accurate Analyses of Trace Elements.

Complete sample digestion is a prerequisite for acquiring high-quality analytical results for geological samples. Closed-vessel acid digestion (bomb) has typically been used for the total digestion of refractory geological samples. However, the long digestion time (4-5 days) and insoluble fluoride complexes still pose challenges for digesting refractory geological samples using this approach. In this study, an efficient and simplified digestion technique combining ultrafine powders from planetary ball milling with bomb digestion was developed for trace element analysis of refractory geological samples: peridotite and granitoid. The method shows two significant improvements compared with previous approaches. (1) By performing dry planetary ultrafine milling, the initial 200 mesh peridotite (<74 μm) could be reduced to 800 mesh (<20 μm) in 6 min at a ball-to-powder mass ratio of approximately 15 using 3 mm tungsten carbide milling balls. (2) Complete peridotite and granitoid dissolution were achieved in approximately 2 h, 60 times faster than what is achievable using previous methods (2 h vs 120 h). Moreover, ultrafine powders effectively suppressed insoluble fluoride formation during bomb digestion. A suite of peridotite and granitoid reference materials were measured to evaluate the stability of this method. This efficient, simple, and reliable sample digestion method could benefit geological, food, environmental, and other fields requiring solid sample decomposition via wet acid, fusion, combustion, or dry ashing.

Cadmium isotopes analysis of environmental samples with high organic matter by dry ashing method under wet plasma conditions

The acquisition of accurate Cd isotopic compositions and high tolerance of interfering elements during measurements were achieved by means of quartz microfiber filter membrane-wrapped samples for dry ashing and wet plasma conditions.

Glycemic Index Values of Stiff Porridge (Ugali) Prepared from Maize, Millet, and Sorghum Flours: Which One for Diabetes Management?

Background. The prevalence of diabetes mellitus is increasing worldwide. Knowledge of glycemic index (GI) is important in its prevention and management. The GI measures how rapidly or slowly the blood glucose increases after food consumption. Stiff porridge (ugali) is an African cuisine that can be prepared from various cereal grains and consumed alongside a relish, including milk. The impact of cereal grain type and milk on the GI of ugali is not understood. Objectives. To determine the GI of ugali prepared from maize, millet, and sorghum and establish the impact of fermented milk on the GI. Methods. Proximate composition was determined using the Association of Official Analytical Chemists methods. Moisture, fat, protein, ash, and crude fiber content were determined by oven drying, soxhlet, Kjeldahl, dry ashing, and Hennenberg and Stohmann methods, respectively. Carbohydrate content was determined by difference. The GI was determined using standard procedures (ISO 26642:2010). Blood sugar response curves were generated using Microsoft Excel software. The GI was computed by dividing the incremental area under the curve (IAUC) of test food by the IAUC of glucose and then multiplied by 100. Data were analyzed using GenStat 14th Edition software. Results. Maize ugali had significantly higher carbohydrate content as opposed to millet or sorghum ugali (P&lt;0.05). The GI for plain ugali followed the order sorghum (72) &gt; maize (67) &gt; millet (46). When consumed alongside fermented milk, the GI order was maize (70) &gt; millet (67) &gt; sorghum (57). Conclusion. Millet-based ugali may be used in the management of diabetes. Fermented milk lowers the GI of sorghum ugali and increases the GI of maize and millet ugali.

Production of phytoliths in woody plants of the Atlantic Forest in islands of the Paraná River, Brazil

The analysis of phytoliths is a recent addition to the geosciences and has found applications in various fields over the last few decades, including palaeoenvironmental studies in fluvial environments. As a developing field, it is essential to carry out studies aimed at creating a modern reference collection that fills an information gap on the production of phytoliths by plants in this environment. These studies are essential to increase the reliability and accuracy of phytolith research in reconstructing past vegetation patterns and compositions. This study is the first with the aim of creating a pioneer collection of phytoliths in fluvial environments of the Upper Paraná River, addressing woody eudicotyledon species of greater representation on the Três Ilhas (Three Islands) Archipelago. The phytoliths were extracted from the leaves of 51 species from the botanical collection of the Nupélia herbarium (HNUP) using the dry ashing extraction method. The analysis found that 21 plant families established on the site have some kind of silica accumulation and 34 species are producers of phytoliths with an identifiable shape and size (<5um). It was confirmed the Moraceae family produces Acute bulbosus (with ramifications), both considered diagnostic at family level. Confirming the current literature on the subject, redundancy of the spheroid ornate and spheroid psilate morphotypes was observed in woody plants. Although no new morphotypes were found, the information will contribute to studies on the evolution of fluvial geoforms.

The effect of plant size on the phytoliths characteristics of short cells in the leaf epidermis of Dactylis glomerata L.

The present study is devoted to the revision of the influence of plant organs size on the size of phytoliths. Phytolith size parameters are used to identify cultivated grasses species in archaeological sites. Understanding how these characteristics are variable is necessary in such studies. The study of the variability of the phytoliths morphometric parameters will increase the possibilities of their use in plant systematics. The article presents a correlation analysis between the average values of the morphometric characteristics of Dactylis glomerata phytoliths from six different habitats with leaf sizes and generative shoots. The cock’s-foot specimens from forest, meadow and anthropogenically disturbed plant communities in the mountainous and plain parts of the south of Western Siberia were studied. Extraction of phytoliths was carried out using dry ashing. The measurement was made using the ImageJ software. Past 4.03 programs was used for statistical processing. The influence of the leaf length on the average values of the parameters of width, equivalent diameter, and inscribed radius of phytoliths of short epidermal cells of leaf was revealed. With an increase in the size of the leaf, the width of the phytolith and the parameters associated with it increase. The length of phytoliths, their area, perimeter, area and perimeter of the described figures weakly depend on the size of the vegetative organs of plants.&#x0D; Key words. Crenate, Dactylis glomerata, morphometry, phytoliths, short cells.

ANALISIS PROKSIMAT KEPITING PASIR (Ocypode Cursor) SEBAGAI SUMBER MAKANAN BERGIZI BAGI MASYARAKAT PESISIR DI KECAMATAN SALAHUTU PULAU AMBON

Background: The use of the Ocypode Cursor sand crab as a source of nutritious food for coastal communities in the Salahutu District area is because this marine animal is found living in sandy substrates along the coast and can be used as a source of nutritious food for coastal communities. Methods: Water content measurement was carried out using the oven method. Determination of ash content is carried out using the dry ashing method. Determination of fat content was carried out using the Soxhlet method. Analysis of protein levels using the Kjeldahl micro method. Results: The results of proximate analysis of sand crab for 100 grams of meat showed a water content of 79.72%, ash content of 6.82%, fat content of 7.5%, protein content of 15.7%. Conclusion: The results of the analysis show that there is a significant regression according to the regression provisions y = a + bx= 3,266 + 0.016, and the value of R2 = 0.802, even the analysis also shows that there is a significant influence according to the value of df = 24-22 = 2 with the value of F = 44,588 with a significance level of 000, &lt; p 0.05, this means that there is a significant influence between the availability of the Ocypode cursor sand crab population in its habitat and Ocypode cursor as a source of nutritious food for the community (OcMGz).

Determination Of Some Trace Elements In Some Lipstick Products By Inductive Coupled Plasma-Mass Spectrometry

Cosmetics have been attracting the attention of humanity since it existed. Over the years, the reach of the cosmetics industry has increased exponentially. In recent years, cosmetic manufacturers have developed many formulations on cosmetic products that are brighter in color, more permanent and not easily affected by external factors. However, heavy metal powders are used while producing these formulations especially inside in dyestuffs and stabilizers. Cosmetic products can be absorbed through the skin and cause systemic toxicity. Hundreds of chemicals are used in many cosmetic products such as make-up products, shampoos, creams, aftershaves, and these chemicals may cause significant health problems. Thus, this study is designed to investigate the heavy metal content of lipstick samples which are used extensively by women. Determination of aluminum (Al), chromium (Cr), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), elements in 35 different lipstick samples (including 15 brands) were performed by Inductively Coupled Plasma-Mass Spectrophotometer (ICP-MS) device. Before the analysis, two different solubilization methods, wet solubilization and dry ashing, were applied to the samples in order to take the metals in the lipstick samples into inorganic environment

δ238U of Coal Reference Materials Determined by MC‐ICP‐MS

Uranium (U) associated with coal can be an important source of U and result in environmental pollution during coal combustion. In this study, we developed a method for measurement of U isotope ratios in coals using multiple‐collector inductively coupled plasma‐mass spectrometry. The 233U‐236U double‐spike was utilised to calibrate the instrumental isotopic fractionation. High‐pressure bomb and dry ashing were adopted to digest the coal samples. The δ238UCRM‐145 values obtained from the two different digestion procedures were in good agreement. The δ238UCRM‐145 of seven coal and one fly ash reference materials are reported. Furthermore, the results of fly ash, bottom ash and feed coal samples reveal that the combustion processes lead to relatively small U isotopic fractionation between the samples within the same coal‐fired power plant, indicating that U isotope data can be used as a tracer for heavy metal pollution resulting from coal combustion. The U isotope measurement method of coal established in this study provides technical support to understand the behaviour of U during coal formation and combustion.

Evaluation of Heavy Metals in Catfish and Tilipia Fish from Bayelsa River Nigeria

The volume of heavy metals in two different fish samples were examined in this report, dry ashing was adopted to digest the samples and the determination of the heavy metals were evaluated using atomic absorption spectrophotometer. from the analyzed sample the concentration of cadimium in all the samples analyzed were below WHO permissible limits which is 0.2 mg/kg, From the different analyzed samples the concentration of lead was below the WHO’s allowable limits which is 0.05 mg/kg, however, catfish and tilapia fish samples gotten from Amasomma have the highest concentration of lead 0.0042 ±0.0021 and 0.0030 ±0.001 respectively. The concentration of cadmium, Aluminium and Manganese are below WHO permissible limits for these heavy metals.

Phytoliths analysis in root, culm, leaf and synflorescence of Rostraria cristata (Poaceae).

Phytoliths (siliceous structures) present in the plants have been employed in the fields of taxonomy and archaeology for many decades. Rostraria cristata is an economically important grass species (Poaceae) which accumulates silica in its different organs in the form of phytoliths. In order to understand the pattern of phytolith production and biochemical architecture of silica in R. cristata, leaf epidermis (blade) using the clearing solution method and different organs using the dry ashing method, X-ray diffraction and Fourier-transform infrared spectroscopy techniques were analyzed. Both abaxial and adaxial leaf epidermis showed the presence of acute bulbosus, rectangular sinuate and stomata phytolith morphotypes. Leaf including sheath and blade had the highest silica content. Characteristic phytolith morphotypes were present in different organs. A total of 34 phytolith morphotypes were present among which nine (9) were articulated and 25 were isolated forms. The most abundant were elongate scrobiculate (48.20%) in root and rectangular sinuate (26.16%) in leaf part. Other common phytolith morphotypes present in different organs of R. cristata were articulated elongate irregular, articulated elongate scrobiculate, acute bulbosus, and polygonal rondel etc. Leaf and synflorescence had the highest similarity based on presence/absence of phytolith morphotypes (Jaccard's similarity index). XRD studies revealed the presence of cristobalite, quartz, tridymite, zeolite etc. forms of silica in different organs. FTIR spectra showed that inplane stretching vibration of Si-C was unique to root, anti-symmetric stretching vibration of C-H was unique to leaf and Al2O3.SiO2 was found in synflorescence only. Our results show the characteristic pattern of phytoliths production in R. cristata.

The influence of heat on phytolith morphology and implications for quantifying archaeological foxtail and common millets

Phytoliths are silica bodies formed in living plant tissues, and they can be reliable indicators of their parent plants when they demonstrate characteristic phytolith morphology. As shown by the growing case studies around the globe, phytolith morphology is of significant value for identifying and even quantifying domesticated plants. However, researchers also alert that phytoliths morphology can change, for example, in alkaline solutions or heat, causing the loss of characteristic phytoliths and eventually leading to the over- or under-identification of certain phytoliths. Focusing on the degree to which heat can cause changes to the phytolith morphology of millet, the present study carried out a series of controlled heating experiments on six varieties of modern common millet (Panicum miliaceum) growing in different regions of Northern China. Husked grains were heated following the dry ashing method. Specimens prepared from the dry ashing method were examined under an optical microscope to quantify articulated husk phytoliths, which are characteristic millet phytoliths, and to estimate the surface area of millet grains. We estimated that 30.8% to 59.5% of the common millet phytoliths underwent morphological damage in the heating experiments. Considering our previous heating experiments on foxtail millet, we conclude that compared to foxtail millet phytoliths, common millet phytoliths experience morphological damage more quickly when exposed to heat. This observation may explain (at least partially) the contradictory results between macro- and micro-botanical results. It reminds us that common millet can be underrepresented in the micro-botanical evidence (phytoliths). We conclude the paper by discussing the potential archaeological implications of our heating experiments.

Analisis Proksimat Bronok (Acaudina Malpadioides)

Karimun Regency, Riau Archipelago Province has an ocean with abundant marine life and has not been used optimally. Bronok (Acaudina malpadioides) is a type of marine biota that lives in muddy coastal areas. Bronok on Karimun Island is consumed fresh and is believed to reduce joint pain. This study aims to determine the content of water, ash, fat, protein and carbohydrates in bronok (Acaudina malpadioides). The proximate analysis includes the water content test using the thermogravimetric method, the ash content using the dry ashing method, the fat content method (Soxhlet), the protein content method (Kjeldhal), and the carbohydrate content method (By different). Bronok that has been analysed for proximate content is found to be present at 16% water content, 29,2% ash content, 5,39% fat content, 11,25% protein content and 38,16% carbohydrate content.

Comparison of three digestion methods for determination of lead and cadmium in milk and dairy products

Background: Toxic metals enter the human food chain through water, soil, and plants. High consumption of dairy products makes it necessary to measure their concentrations in milk and its products. Methods: In this study, four samples of dairy products, including milk, dough, yogurt, and cream were selected. They were spiked with concentrations of 0, 20, 40, and 60 μg/kg of lead (Pb) and cadmium (Cd) separately. In all samples, the concentration of these metals was determined using graphite furnace atomic absorption spectroscopy (GFAAS) after microwave, wet, and dry ashing digestion methods. To select the best digestion method, recovery percentage, linearity of increasing concentrations, relative standard deviation (RSD), and the limit of detection were used. Results: According to the results, the RSD of all measurements was less than 5%. The instrument detection limit for Pb and Cd were 0.188 and 0.157 μg/L, respectively. The recovery efficiency of all digested samples by three methods was between 75.7% and 120%. According to the linearity index and R2 , the microwave digestion method with 90 to 110% efficiency was the best for Pb-spiked samples, and the dry digestion method was the best for Cd-spiked samples. Conclusion: Considering all indexes, microwave digestion was the best method for Pb and Cd samples.

Sample Preparation and Analytical Techniques in the Determination of Trace Elements in Food: A Review

Every human being needs around 20 essential elements to maintain proper physiological processes. However, trace elements are classified as beneficial, essential, or toxic for living organisms. Some trace elements are considered essential elements for the human body in adequate quantities (dietary reference intakes, DRIs), while others have undetermined biological functions and are considered undesirable substances or contaminants. Pollution with trace elements is becoming a great concern since they can affect biological functions or accumulate in organs, causing adverse effects and illnesses such as cancer. These pollutants are being discarded in our soils, waters, and the food supply chain due to several anthropogenic factors. This review mainly aims to provide a clear overview of the commonly used methods and techniques in the trace element analysis of food from sample preparations, namely, ashing techniques, separation/extraction methods, and analytical techniques. Ashing is the first step in trace element analysis. Dry ashing or wet digestion using strong acids at high pressure in closed vessels are used to eliminate the organic matter. Separation and pre-concentration of elements is usually needed before proceeding with the analytical techniques to eliminate the interferences and ameliorate the detection limits.

Potassium, sodium, calcium and magnesium levels of commonly consumed foods and estimates of dietary intakes of selected Nigerian adults

Micronutrient deficiency is a public health challenge globally, as it affects both people and the economy. In Nigeria, most micronutrients, especially minerals are lost during food processing. The study was carried out to determine the potassium, sodium, calcium and magnesium composition of foods commonly eaten by Nigerian adults and to estimate the average adults' daily intake of these macrominerals. The contents of these minerals in 141 food items collected ‘as consumed’ from 10 locations in Federal Capital Territory, Abuja and Ogun State, Nigeria, were quantified by digesting the foods through dry ashing and analysed using flame atomic absorption spectrometer. The levels (mg/100 g fresh weight) of potassium, sodium, calcium and magnesium in the various foods ranged from 2.92 to 1520, 1.46 to 30,700, 1.35 to 1280 and 1.16 to 416, respectively. Recovery values were within the range of 95–110%. Adults' mean mineral intakes (mg/person/day) of the analysed foods were 1970 ± 780, 2750 ± 1100, 423 ± 300 and 389 ± 130 for potassium, sodium, calcium and magnesium, respectively. Mean sodium intake was higher while potassium and calcium intakes were lower compared with international recommendations (mg/person/day) of 1500, 2300–3400 and 1000–1300, respectively; indicating the need to enlighten consumers. The snapshot data from this study are useful to update the Nigerian Food Composition Database.

Mass spectrometric investigations into 3D printed parts to assess radiopurity as ultralow background materials for rare event physics detectors

New data are reported for polyvinylidene fluoride (PVDF), polyphenylene sulfide (PPS), and two forms of polyetherimide (PEI, branded ULTEM 1010 and 9085). Data for starting filaments and both simple and complex printed parts are reported. PVDF filaments and simple printed beads, were found to have values of approximately 30 and 50 ppt for Th-232 and U-238, respectively, while a more complex spring clip part had slightly elevated Th-232 levels of 65 ppt, with U-238 remaining at 50 ppt. PPS filament was found to have concentrations of 270 and 710 ppt for Th-232 and U-238, respectively, and were not chosen to be printed as those levels were already higher than other material options. ULTEM 1010 filaments and printed complex spring clip parts were found to have concentrations of around 5 and 7 ppt for Th-232 and U-238, respectively, illustrating no significant contamination from the printing process. ULTEM 9085 filaments were found to have concentrations of around 9 and 5 ppt for Th-232 and U-238, respectively, while the printed complex spring clip part was found to have slightly elevated concentrations of 25 and 7 ppt for Th-232 and U-238, respectively. These results were all obtained using a novel dry ashing method in crucibles constructed of ultralow background electroformed copper or, when applicable, microwave-assisted wet ashing digestion. Samples and process blanks were spiked with Th-229 and U-233 as internal standards prior to dry/wet ashing and determinations were made by inductively coupled plasma mass spectrometry (ICP-MS). In order to maintain high radiopurity levels, pre-cleaning the filaments before printing and post-cleaning the parts is recommended, although the printing process itself has shown to contribute very minute amounts of radiocontaminants.