Calcium sensor for water. 3ml sample (or 0. The integration of all-solid-state ion-selective determination allows Calcium is much needed for animals to build strong teeth and bones. The Replacement Calcium Sensor is compatible with HORIBA LAQUAtwin Calcium Meter models Ca-11 and B-751. Features Measurement of calcium ions in water or liquid Industrial code, calcium ion sensor, calcium analyser Linear continuous measurement Replaceable Milk fever, or Sub Clinical Hypocalcemia (SCH) is a significant problem with dairy cows. Genetically encoded calcium sensors that can be expressed inside cells by transfection or transgenesis are desirable. The Atlas sensors can be installed on the water pipe leaving a water softener. Calcium-saturated crystal structures of all these sensors are available in the PDB (Figure 1 A,B,C,F). A basic digital hardness sensor for conventional water quality monitoring; it is made of industrial online electrodes and PVC membrane ion-selective electrodes, which can selectively test water hardness, with fast response and accurate measurement. Flat sensor technology enables accurate measurements with only a few drops of sample. However, these Soak the electrodes in distilled water for 10 minutes, and then soak the calcium electrode in a diluted calcium standard solution (1 ppm) and the chloride electrode in a diluted chloride standard solution (1 ppm) for two hours until ready for use. present a scheme that combines battery and pressure sensor in one device. The calcium ion electrode is an ion exchange sensor that is selec ve for calcium ions but many anions also interact with the sensing membrane. Additionally, this is also the first report on colorimetric determination in serum of any of these ions in paper-based format. com At Sensors Expo today, Libelium announced the addition of ion selective sensor probes to the Waspmote Smart Water sensor platform, for increased sensitivity and accuracy in water quality monitoring. Food and Beverage Industry: For quality control in products like dairy and bottled water. This high accuracy water quality sensor can operate in the range of 0-50°C and at a pressure range of 0 to 2 atm. 3D printed moulds were developed as the master templates on which MWCNTs and PDMS were cast at specific heights. The new LAQUAtwin CA-11C has been specially developed for cow side measurement of ionized calcium in blood. In recent years, the development of soft computing tools based on ML techniques in the fields of water and envi-ronmental engineering has received wide attention [9 Nov 15, 2023 · On the other hand, electrochemical sensors offer many advantages over other kinds of calcium ion sensors owing to their affordability, high sensitivity, selectivity, rapid response time and low power consumption. Using just a tiny amount of sample, the LAQUAtwin proprietary flat sensors can quickly and accurately measure the values of the chemical Jun 1, 2019 · Plenty of ISE calcium or water hardness sensors are available in the current market [34]. The soft sensor is a feasible and economical alternative to expensive or impractical physical measurement sensors [6–8]. . The sensor is fully automated, handling sample taking and preparation without human intervention. We validated GreenT-ECs in rodent hippocampal neurons and transgenic zebrafish in vivo, where the sensors enabled monitoring homeostatic regulation of tissue interstitial calcium. S80 Intelligent Calcium Sensors are an inline continuous measurement sensor with replaceable electrode cartridge for use with the T80 Universal Transmitter. Detecting into the PPB, the sensor can handle water from heavy industrial matrices to drinking water applications. Automatic Online Calcium Analyzer – Dedicated Control of Calcium in Water Because calcium hardness impacts equipment life and product quality, constant monitoring is essential. We offer the largest selection of sensor technologies for multiprobes in the industry. Keywords: calcium sensor, deoxyribonucleic acid ionophore, calcium determination 1. Our high-quality water processing sensors designed to meet the specific needs of your water treatment application. The Horiba LAQUA Twin Calcium ion meter makes testing dissolved Calcium extremely easy by simply placing a tiny sample on the meter's flat sensor. However, the replaceable module of ISE Get accurate calcium levels with water quality testing from KETOS. Introduction Metal ions are closely associated with the development of biological environments, industrial manufacture, and human Determining the calcium content of drinking water helps consumers accurately gauge their calcium intake. GCaMP2 is the earliest designed sensor in our set. Field of application Liquiline System CA80HA offers precise online analysis of water hardness in drinking water and process water. Mercury, iron (ll), Copper (ll), nickel (ll) and ammonium interfere at 1000 - 3000:1. No need for a beaker to calibrate your meter or measure a sample. 2~40000 for sale. Integrated Temperature Sensor: Ensures accurate compensation across a temperature range of 0 - 50 °C. Lead ions strongly interfere with but many anions also interact the measurement, 2 Lead ions = 1 Calcium ion. so it can save much Hardness Sensor General water hardness is related to the minerals dissolved in the water. These sensors provide valuable data support for researchers and are widely used in laboratory studies, marine water quality assessments, aquaculture, and wastewater treatment. The method is suitable for both colored and colorless samples such as groundwater, surface water, wastewater, and drinking water. The norm ASTM D8192 presents automated photometric titration for water hardness determination. Nanocomposites can provide solutions for such multiple challenges while showing high performance and cost-effectiveness. Thus, it is very important to monitor drinking water hardness. Unique sensor allows measurement of viscous liquids, solids, and even powder samples. The sensor was used effectively for the estimation of calcium in real samples (fruits, calcium syrup, milk, and dairy products). Here, we demonstrate a facile fabrication method of calcium ion sensor for water quality monitoring. Its versatility is guaranteed on the one hand by a cell type-specific Ca 2+ signaling toolkit. Ideal for measuring water, soil, leaf sap, milk, juice, fertilizer solutions and more. In this work, the Cu-Fe Jun 1, 2022 · Regulation of the calcium-sensing receptor in both stomatal movement and photosynthetic electron transport is crucial for water use efficiency and drought tolerance in Arabidopsis Description Overview GAOTek calcium ion sensor probe is a kind of electrode sensor which is used to measure the content of Ca2+ in the solution. However, these devices are bulky and require specialized staff for operation and evaluation. Calibration and Cleaning of Calcium Selective Ion Measurement System For Waste Water Calcium Analysis ê All calibration solutions and Process Grab Sample should be calibrated and tested at identical temperatures to the process temperature to minimize errors due to temperature effects. China Water Calcium Sensor Probe wholesale - Select 2025 high quality Water Calcium Sensor Probe products in best price from certified Chinese manufacturers, suppliers, wholesalers and factory on Made-in-China. Here’s where calcium ion measurement is necessary: Water Treatment: To manage water hardness and prevent equipment damage. The printed carbon substrate electrode was modified by dropcasting aqueous dispersion of PEDOT:PSS and then coated with a calcium ionselective membrane. Read more. Flexible battery-type pressure sensor enhanced with locked water by calcium ion in graphene oxide solid electrolyte Lei et al. Simultaneous detection of both ions allows for fast and user-friendly screening of disturbance in Oct 22, 2025 · The Horiba LAQUAtwin Ca-11 Compact Calcium Ion Meter # 3200689161 is the only pocket meter that directly measures calcium ion concentration in 0. By measuring the ionized calcium levels of the blood directly cow side, the treatment can start sooner and is more effective. Ionized The Horiba LAQUA Twin Calcium ion meter makes testing dissolved calcium easy. , Ltd. Low Maintenance: It contains our original gel formulation, eliminating the need for refilling solution. May 15, 2025 · Calcium ion sensors are essential in clinical diagnosis, particularly in the management of chronic kidney disease. Applications include, but not limited to: Water Softening Systems, Drinking and Mineral Waters, Blood Elecrtrolytes/Clinical Analysis. Depending on the number of calcium and magnesium ions, a low or high voltage is generated, which is transmitted Sep 6, 2024 · Hardness is one of the basic parameters of water, and a high-level hardness of drinking water may be harmful to human health. Despite their widespread adoption and utility, they suffer some disadvantages. This analyzer detects calcium as a major component of hardness in real time, providing accurate and reliable results. While calcium is an essential mineral for human health, its presence in drinking water is a double-edged sword. It helps you to optimize the control of water softening processes in drinking water applications and the optional dilution module allows water hardness measurements with concentration up to 1600 mg/l. Multiple approaches have been developed to measure calcium ions, including flame photometry and ion chromatography. Having too little calcium in Abstract Small, fluorescent, calcium-sensing molecules have been enormously useful in mapping intracellular calcium signals in time and space, as chapters in this volume attest. Unlike atomic absorption spectroscopy (AAS) and inductively coupled plasma atomic emission spectroscopy (ICP), the LAQUAtwin calcium ion meter offers a simpler method for measuring calcium ion - ionizing bound calcium in water using acid before analysis. IMPORTANT NOTE: Calibration standards are essential for creating the calibration curve in calcium ion sensors. Note: Vernier products are designed for educational use. GAOTek Calcium Ion Electrode Meter is a basic digital hardness sensor for conventional water quality monitoring; it is made of industrial online electrodes and PVC membrane ion-selective electrodes, which can selectively test water hardness, with fast response and accurate measurement. 400 subscribers Subscribe Calcium in drinking water is a key factor in water quality and public health. Cleaning caked scale is a massively expensive proposition Monitoring and preventing scale is a much more economical choice for most facilities. Built-in temperature sensor, automatic temperature compensation, suitable for online long-term monitoring environment. For instance, Almeida Water quality is a major concern for individuals and communities alike, especially when it comes to drinking water. Combined with data logger and software, it can be real-time to measure the content of calcium ion. Includes a calcium sensor electrode, calcium Ionic strength adjuster (ISA), calcium 1000 ppm standard. Like all other PVC ISE membranes, the membrane on the ISE has a limited life expectancy. This mineral can affect health in good and bad ways. In recent decades, the development of calcium ion sensors has been the focus of significant research efforts, resulting in a number of noteworthy achievements. Testing calcium in water with ion sensors What Calcium is and How to Measure it in Water Calcium is an alkaline-earth metal that is an important component of the cell walls of aquatic plants, and of the bones and shells of aquatic animals. Low price calcium sensor for water quality with measurement range 0. Plants utilize multiple sensors and signalling components, most of which are intricately involved in Ca sensing and signalling, to perceive and respond to salinity stress. Using Ion Selective Electrode (ISE) technology, they are available for measuring Conductivity, Calcium, Nitrate, Potassium, Sodium, Salt concentration and pH measurement. Uses a permanently filled ion selective electrode to accurately measure the amount of calcium ion in a solution. In this work, a portable lateral flow distance-based paper sensor for the semi-quantitative detection of drinking water hardness is demonstrated. Suitable for rivers, tap water, industrial wastewater, leachate, seawater, mining water, soil, cement. As a second messenger, Ca2+ links Calcium Ion Sensor S050 Replacement sensor for LAQUAtwin B-751 and Ca-11 Requires a minimum of 0. It is an improved version of the original GCaMP, the first single FP-based Ca 2+ indicator, and is derived from circularly permuted EGFP (Figure 1 D–F). Sensitive sensing, supports online monitoring. A Calcium Ion Selective Electrode sensor specifically designed to measure 0. Water hardness is a measure of the amount of calcium and magnesium ions in the water, usually expressed in milligrams per liter (mg/L). 5 ppm to Saturated (5x10-6 M to Saturated) concentrations of Ca2+. As the water softener’s resin is exhausted, calcium will begin to appear in the softened water. Ca 2+ is detected by specialized motifs on proteins, which have Direct Connection: This calcium ion sensor cartridge connects directly to 300-I-2 or 300-I-5 ion sensor head without the need for an adapter. Calcium in Water is the principle cation in fresh water is important component of water harness. Contributes to reduction of chemical usage in the wastewater treatment process by continuously monitoring calcium ion concentration in the tank. Accurate calcium measurement is crucial in applications such as aquarium maintenance, swimming pool management, water treatment, and clinical diagnostics. Calcium ions interact directly with a specialized electrode membrane at the end of the probe. Plants are exposed to various environmental stresses. Nov 3, 2022 · The developed fluorescent calcium sensor displayed good water dispersity and biocompatibility. It connects via Bluetooth® wireless technology or via USB to your device. 05 ml with sampling sheet B) Sensor guard has a sliding cap for scooping water sample Waterproof Download a free copy of the Calcium Ion Selective Electrode Application Guide and get more information about theory, principle and calibration for this type of ion measurement. 3 ml sample with direct measurement (0. Total calcium levels in the cows’ blood drop after lactation. In the same way calcium builds strong cell walls for plants and fruits. The WaterGuru SENSE S1 uses patented optical technology to measure daily the Free Chlorine (FC)and acidity (pH) of your pool water. Its versatility is guaranteed on the one hand by a cell type-specific Ca2 + signaling toolkit. The Automatic Online Water Hardness Analyzer by NT Sensors delivers real-time, reagent-free measurement of calcium and magnesium in water systems. Environmental Monitoring: To assess the health of natural water bodies. 05 ml with sampling sheet B) Sensor guard has a sliding cap for scooping water sample Waterproof The Vernier Calcium Ion-Selective Electrode is used to measure the concentration of calcium (Ca 2+) ions in aqueous samples. The working life of the calcium ion electrode (ISE) is over one year, because the ion sensor membrane is special designed by BOQU Instrument and it can be replaced in period according to water quality at site. Measurements are simple, quick, and accurate. Moreover, detection of such cations in water samples using simple portable techniques is required for monitoring and inspection of water quality. The Orion 2120XP Analyzer continuously displays levels of calcium hardness to prevent against boiler tube scaling, corrosion, water flow restriction and the loss of heat transfer efficiency for power generation applications. Studies have looked at how these minerals in water affect […] The WaterGuru SENSE is a smart device that’s installed on your skimmer with its Sensor dangling in the water in the skimmer basket. Jun 5, 2024 · Water softening is a treatment process required to manage calcium and magnesium cations in water streams. The ISE calcium meter with *ionic analysis system (*laboratory precision) allows direct measurement of the exact concentration of pH and calcium. Aquaculture: For maintaining fish health and water quality. Apr 20, 2023 · NEMO sensors further enable the quantification of absolution calcium concentration with ratiometric or photochromic imaging. Molecular Probes prepares these indicators in the water-soluble potassium salt form The calcium ion /hardness electrode is an ion exchange sensor that isselecve for calcium ions with the sensing membrane. Many people don’t know about the calcium in their tap water. Through the sensor membrane diffuse calcium and magnesium ions from the sample liquid to the inner electrolyte in an effort to build an equal ion concentration on both sides of the membrane. A calcium meter, also known as a calcium analyzer or calcium tester, is an essential tool for measuring calcium concentration in water, biological samples, and industrial solutions. The WaterGuru SENSE S2 uses patented optical technology to measure daily the Free Chlorine (FC), acidity (pH), Total Alkalinity The sensors were used for determining a range of concentrations of calcium and magnesium solutions in water bodies. BH-485-ION is a digital ion sensor with RS485 communication and standard Modbus protocol. Calcium and magnesium in drinking water can impact cardiovascular health. The ratio of calcium to magnesium is generally fixed, typically in the ratio 3:1 (Ca:Mg), therefore Total Hardness can be inferred, by knowing the amount of calcium present. 05ml sample with sampling sheet B). Maximize process integrity while maintaining the best possible return on investment with an all-in-one system that provides early detection of breakthrough due to zeolite Sensor to Measure Hardness of Water: By Annika Schalk and Mitali Uke Hardness of water is the amount of metallic ions, mostly calcium and magnesium in the water. Our products are not designed nor are they recommended for any industrial, medical, or commercial process such as life support, patient diagnosis, control of a manufacturing process, or industrial testing of any Field-installation type calcium ion meter HC-200CA For treatment of hydrofluoric acid wastewater from semiconductor production. A free white paper describes the determination of total, calcium, and magnesium hardness using the optical sensor Optrode from Metrohm for more reliable, accurate, and precise measurements compared to manual titrations. When the ions interact with the electrode’s membrane a small voltage is generated. Probe + ISE Calcium is a half-cell ion selective electrode (ISE) ( non-integrated reference) with a robust, solid-state PVC (polymer) membrane selective to calcium ions in solution. On the other hand, the fine compartmentalization of changes in Ca 2+ concentration ( [Ca 2+]) into specific subcellular domains adds a level of complexity, thus generating a The developed fluorescent calcium sensor displayed good water dispersity and biocompatibility. A key component that often comes under scrutiny is the concentration of various minerals in water, one of the most notable being calcium. The Calcium ISE has a combination-style, non-refillable, gel-filled electrode. The sensing of environmental cues and the transduction of stress signals into intracellular signaling are initial events in the cellular signaling network. Measurement Of Calcium In Drinking Water LAQUAtwin is a series of pocket ION meters. Selective control of specific targets depends on spatio-temporal patterning of the calcium signal and decoding it by multiple, tunable and often strategically positioned Ca 2+ sensing elements. The analyzer's automatic calibration and cleaning and its low Water quality calcium ion sensor with flow cell Honde Technology Co. The Automatic Online Calcium Analyzer by NT Sensors delivers real-time, reagent-free measurement of calcium levels in any water system. Calcium SensorCalcium Ion in water / liquid measurement Industrial Specifications - Calcium IonSensor - Calcium Analyzer Inline continuous measurement - direct insertion in pipes, tanks, or open channel Replaceable electrode cartridge - only replace the sensing element not the complete sensor Adjustable gland fitting for varying insertion length Easy calibration that is stored in the sensor Solinst Eureka Water Quality Sondes Established in 2002, Solinst Eureka is a global leader in designing and manufacturing multiparameter water quality sondes. Apr 15, 2020 · The design, fabrication, and implementation of novel flexible sensors for electrochemical detection of multiple minerals such as calcium and magnesium… Nov 21, 2024 · Crown Ether-Based Calcium Detection in Aqueous Solution: Simon Wheeler, UK, discusses his new fluorescent sensor for Ca²⁺ Atlas produces IoT sensors to detect calcium and other ions in water, allowing real-time detection of water quality to improving reliability and efficiency. RealTech Controls offers two types of Water Hardness Analyzers: The model ETX Transmitter is an online, real-time analyzer and uses the S80 Calcium Ion Sensor. Just place few drops of the standard or sample Varify Water Hardness Test Kit - Water Testing Kit for Home, Drinking, Well, Spa, Swimming Pool, Softener, Dishwasher & More - Hard Water Test Strips for Calcium, Magnesium etc (0-425 pmm, 150 Strips) 5K+ bought in past month Save 5% on 2 select item (s) Small Business Summary Ca 2+ is a ubiquitous intracellular messenger that controls diverse cellular functions but can become toxic and cause cell death. We offer a selection of membrane-permeant and impermeant fluorescent indicator dyes for calcium and other ions, as well as calibration buffers, ionophores, and accessory reagents. This voltage is compared against the voltage in the internal reference electrode and The AquaValid sensor can connect to any pipe or flowing system, and monitor on a real time basis for up to five metals. Learn more about the measurement and impact of Calcium and Magnesium ions on water quality. Determining the calcium content of drinking water helps consumers accurately gauge their calcium intake. Additionally, this novel nanoprobe has been utilized for the determination of calcium ions in MCF 7 cell lysates as well as the detection of calcium ions in water samples from different sources. Reliable insights to help ensure water safety and regulatory compliance. The concentration of Calcium is also used as an endpoint indicator in EDTA-Ca/Mg hardwater titrations. During our research, we mainly focuse… Automatic Online Water Hardness Analyzer – Precise Control of Calcium and Magnesium Because water hardness affects equipment longevity and product quality, you need continuous, accurate data. The Go Direct Calcium Ion-Selective Electrode (ISE) can be used to measure the concentration of calcium (Ca2+) in aqueous samples. On the other hand, the fine compartmentalization of changes in Ca 2 + concentration ( [Ca 2 +]) into specific subcellular domains adds a level of complexity, thus generating a Introduction The long-wavelength calcium indicators Calcium GreenTM, Orego n Green® 488 BAPTA, Calcium YellowTM, Calcium OrangeTM, and Calcium CrimsonTM are visible light-excitable probes derived from fluorescein, Orego n Green® 488 dye, lucifer yellow, tetramethylrhodamine, and Texas Red®, respe ctively. Benefiting by the redox potential conversion mechanism and the water-retention characteristics of calcium ion, this scheme can encode pressure signals into electrical signals, thus converting the Mar 6, 2025 · Water quality sensors utilize chemical, physical, or biological reactions to measure parameters such as conductivity, dissolved oxygen, pH, COD, residual chlorine, and turbidity in solutions. Shop a range of Hach products for water hardness monitoring including water hardness analyzers, test kits, titrators and more. 05 ml with sampling sheet B) Sensor guard has a sliding cap for scooping water sample Waterproof Dec 1, 2023 · During salinity stress, plants employ a diverse array of strategies to optimize water and nutrient uptake in response to the relatively high osmotic potential of the rhizosphere. Walchem has a great selection of wastewater treatment sensors to choose from. The calcium ion electrode of the PXG-2085Pro online calcium ion meter made with a molded calcium PVC membrane. The above problems can be addressed using soft sens-ing technology based on machine learning (ML) methods. Calcium ions find their way into water as it flows over rocks that contain calcium, such as limestone and gypsum. Lead ions strongly interfere with the measurement, 2 Lead ions = 1 Calcium ion. GreenT-ECs may become useful for recording very large calcium transients and for imaging calcium homeostasis in inter-cell structures in live tissues and organisms. Calcium ions find their way into water as it flows over rocks that contain calcium, such as limestone and The only pocket meter that directly measures calcium ion concentration in 0. The Apure HARD-406 all-in-one on-line total hardness sensor uses a PVC membrane based calcium and magnesium ion selective electrode to test the total hardness of water (in terms of CaCO3), with temperature compensation to ensure that the test is fast, simple, accurate and economical. Housing material is corrosion-resistant (PPS+POM), IP68 protection, suitable for most water quality monitoring environments;This online ion sensor uses an industrial-grade composite electrode, the reference electrode double salt bridge design and have longer working life;Built-in temperature sensor and Jun 17, 2019 · The ‘jGCaMP7’ sensors are four genetically encoded calcium indicators with better sensitivity than state-of-the-art GCaMP6 and specifically improved for applications such as neuropil or wide ASTM D8192 describes the photometric titration of the total hardness, calcium hardness, and magnesium hardness in water with an optical sensor for objective endpoint indication, increasing precision and reliability. It is very important to know how much calcium is in your water, in your soil, in your plants, in your milk and in the crops you grow to measure the quality. Together with the S80 Calcium ion sensor, the model ETX water hardness analyzer provides online, real-time values of water hardness, and incorporates programmable mA and relay outputs for control and monitoring. Use the einstein™ calcium sensor to measure the level of calcium in any solution in activities such as determining the hardness of water. Online Calcium Ion Sensor The on-line calcium sensor is manufactured using a PVC film based calcium selective electrode to measure calcium content in water, with temperature compensation to ensure that the test is fast, simple, accurate and economical. Oct 13, 2025 · Herein, a novel paper-based electrochemical sensor for the direct determination of free calcium ions in nasal secretions, providing potential diagnostic biomarker in olfactory dysfunction. The pH also interferes with low level measurements, keep the pH >4 for concentra ons Data from the Calcium ISE can give a good indication of hardness of water (as Ca 2+). Limit the costly effects of improper water purification using the Thermo Scientific™ Orion™ 2120XP Calcium Hardness Analyzer. ICP-MS, based on the mass spectrometer to separate and quantify ions [35], is a much faster, more sensitive and precise method than the others. Running costs and risk of scale generation are reduced by optimizing chemical usage, thereby contributing to stable plant Jan 1, 2020 · Calcium (Ca 2 +) is a universal intracellular messenger capable of governing a plethora of different biological functions. Seawater contains about 400 ppm calcium. Calcium (Ca 2+) is a universal intracellular messenger capable of governing a plethora of different biological functions. Calcium ion sensors are essential in clinical diagnosis, particularly in the management of chronic kidney disease. Click here to learn more. In freshwater, the concentration of The calcium sensor uses a permanently filled ion selective electrode to accurately measure the amount of calcium ion in a solution. In addition to the latest technology for measuring common parameters such as temperature, pH, conductivity, dissolved oxygen, turbidity, and depth Apr 15, 2020 · The design, fabrication, and implementation of novel flexible sensors for electrochemical detection of multiple minerals such as calcium and magnesium… Calcium Ion Sensor S050 Replacement sensor for LAQUAtwin B-751 and Ca-11 Requires a minimum of 0. The resulting electrical voltage is measured and evaluated to determine the water hardness. Calcium Sensor Detect Calcium in Real Time Calcium is a major constituent of water hardness, which can cause machinery damage, additional wear and tear, and increased maintenance costs. The actual temperature of the process solution (and thereby the calibrating solutions as well) is not as Calcium Ion Sensor S050 Replacement sensor for LAQUAtwin B-751 and Ca-11 Requires a minimum of 0. The last 10 years Technical notes: The NeuLog calcium ion sensor can be used for any science experiment or activity which can utilize calcium concentration readings such as in the fields of Environmental Science, Ecology, Chemistry, Biology, etc. The Atlas sensor is able to detect the initial breakthrough of calcium and will send a signal to the softener control valve system indicating regeneration is needed. Jun 15, 2024 · In this paper, a microfluidic paper-based analytical device for simultaneous determination of calcium and magnesium ions in human serum is reported for the first time. Hardness affects the taste of water and also may cause dry skin or rough hair issues. 9j7jr j8pzvg ix4 1jm51 ulob xiy2o rh99d npsr of5 svssya