|
HS Code |
517225 |
| Product Name | Catecholsulfonphthalein |
| Cas Number | 346-18-9 |
| Molecular Formula | C19H12O7S |
| Molecular Weight | 384.36 g/mol |
| Appearance | Dark green to black powder |
| Solubility | Soluble in water and ethanol |
| Melting Point | Approx. 240°C (decomposes) |
| Ph Indicator Range | 7.0 to 13.0 |
| Color Change | Yellow to purple |
| Synonyms | CSP; Sulfonphthalein catechol; o-Cresolphthalein sulfonic acid |
| Storage Temperature | Room temperature |
| Usage | pH indicator |
As an accredited Catecholsulfonphthalein factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Catecholsulfonphthalein is packaged in a 25g amber glass bottle with a secure screw cap, labeled with hazard and identification information. |
| Shipping | Catecholsulfonphthalein should be shipped in tightly sealed containers, away from incompatible substances, moisture, and direct sunlight. Material must be packed according to safety regulations, with appropriate hazard labeling. Ensure stable temperatures during transit and provide documentation detailing handling procedures and safety data to comply with chemical transport regulations and prevent leaks or spills. |
| Storage | Catecholsulfonphthalein should be stored in a tightly sealed container, protected from light and moisture, and kept in a cool, dry, well-ventilated area. Avoid exposure to heat and incompatible substances such as strong oxidizing agents. Ensure the storage area is properly labeled and complies with relevant chemical safety regulations to minimize the risk of deterioration or hazardous incidents. |
Competitive Catecholsulfonphthalein prices that fit your budget—flexible terms and customized quotes for every order.
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Tel: +8615380400285
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Every batch of catecholsulfonphthalein that comes out of our manufacturing facility represents years of hands-on experience. We do not pass this compound through layers of middlemen—what arrives in the laboratory bottle is what we’ve synthesized, dried, and quality checked in-house. This experience matters. Catecholsulfonphthalein, also known in many labs as CASP, serves a unique function in the world of analytical chemistry: it acts as an acid-base indicator and, at times, as a metallochromic indicator. Its bright transition between colors draws a clear line for researchers, students, and industrial analysts, which helps avoid uncertainty and fosters confidence in their results. We’ve seen firsthand how this clarity ripples outward—better indicators improve reproducibility, which directly affects both the pace and credibility of scientific discovery.
Our production process for catecholsulfonphthalein rests on consistency. Over the years, we have refined our reactor conditions and purification steps. Each gram leaves the plant after passing purity checks by thin-layer chromatography and melting point analysis. Typical appearance is a fine, striking green powder that dissolves well in aqueous and mixed organic solvents. The distinct color change—shifting between yellow and greenish-blue over pH 4.5 to 6.8—makes it easily readable, even at low concentrations. Spectrophotometric scanning of randomly selected lots ensures that impurities stay below the detection threshold. The majority of quality complaints in the indicator market stem from two sources: off-shade color change and contamination with other sulfonated dyes. Direct production in our own plant removes the uncertainty of variable sources, which is why many labs prefer to order direct.
Our standard offering of catecholsulfonphthalein comes in crystalline free-flowing powder, with no added stabilizers or fillers. This practice stands apart from suppliers who blend in excipients for easier handling but compromise the clarity or abruptness of the indicator transition. The batch specification targets a purity of at least 99%, with moisture typically below 0.2%. Crystallinity assures low hygroscopicity, which means long shelf life without caking during storage. We maintain strict controls on powder particle size, settling within a narrow distribution. This might seem like an inside-baseball detail, but a reproducible mesh size allows for rapid and complete dissolution right at the start of titration—minimizing lag time and ensuring that color changes align exactly with endpoint chemistry, not formulation artifacts.
In practical analysis work, catecholsulfonphthalein holds a distinct place next to phenolphthalein and thymol blue. While phenolphthalein enjoys popularity for titrations involving strong bases, its abrupt color shift within alkaline pH limits its versatility. Catecholsulfonphthalein offers a mid-range transition, invaluable for buffer analysis, serum protein titrations, and certain complexometric determinations involving transitional and rare earth metals. Unlike bromocresol indicators, our compound avoids muddy, indistinct boundary colors. Years of feedback from university and industrial field labs highlight a consistent preference: for those who perform repeated titrations day after day, the crisp break in color stands out clearly across ambient lighting, whether in a sunlit bench or under fluorescent lab lights. Attempts to substitute watered-down indicator blends quickly reveal the superior readability and stability of our pure catecholsulfonphthalein.
At its core, a laboratory indicator should make doubt disappear. Our chemists select catecholsulfonphthalein in jobs where reproducibility, clarity, and speed matter. Beyond routine pH determination, Catecholsulfonphthalein performs well for calcium and magnesium titrations involving EDTA, thanks to the way its color change lines up exactly with the presence (or absence) of free ions. In wastewater treatment labs, technicians count on its resilience against trace oxidizers—an advantage over methyl orange or methyl red, which sometimes degrade under tough matrices.
Many researchers share candid stories with us: switching to our material removed “mystery” color shifts that used to show up after glassware cleaning cycles or after switching water sources. Our product’s visual sharpness saves time, especially where hundreds of titrations run in a high-throughput schedule. Students learn endpoints more confidently, making fewer errors. In revenue-driven industrial environments, this precision directly reduces rework and repeat tests, saving both money and frustration.
Producing catecholsulfonphthalein in-house means every batch reflects both our accumulated experience and tight process control. Some years back, a university lab approached us after their results began to drift—chromatographic analysis pinpointed dye “bleed” from a mixed-lot purchase. We realized that many academic labs don’t have the option to double-check their suppliers' chain, and that residue—sometimes brought along by third-party repacking—can easily slip into the workflow. We’ve eliminated those possibilities by controlling every production input, regularly monitoring for trace byproducts, and storing the indicator under nitrogen to inhibit atmospheric degradation. Each batch leaves our plant with a measured absorbance curve and verified endpoint data, not just a theoretical certificate.
Our customers return to catecholsulfonphthalein for consistency and readability. Experienced users spot the subtle difference between high-grade and commodity-grade indicator: less background color, more instantaneous shift, and no ghost “bleed” around the endpoint. For students, this means less confusion and quicker mastery. It did not take long for us to hear from contract labs that interventions and repeat tests dropped after making the switch to a single-source product. Teachers at several science centers told us that younger students—who often have trouble matching endpoints—found their confidence returning thanks to a more distinct color break.
Across quality-control labs in the food and beverage sector, the lasting stability of our catecholsulfonphthalein offers another layer of value: product integrity stays higher over months, eliminating concerns about mid-year indicator drift leading to costlier out-of-spec product recalls. One food quality lab estimated they cut validation time by a third; they no longer run fire drills over ambiguous endpoints and can focus on higher-value analysis.
Chemists want transparency and detail—not marketing gloss or evasive language. We maintain a policy of sharing each batch’s spectral data, tested in our in-house laboratory, and work with external partners to survey for persistent matrix-dependent variability. For several years, we conducted quarterly round-robin testing, pooling feedback from users in academia and industry. This practice uncovered a slight “lag” with certain errored pipetting techniques. We adjusted our process accordingly, tightening controls on surface moisture and improving our batch release standards to respond directly to field experience.
Understanding the chemistry behind a product also means appreciating its impacts downstream. Catecholsulfonphthalein, synthesized under careful waste treatment, generates few persistent organic byproducts. Our plant’s scrubbers remove sulfur dioxide, and our closed-filter lines capture unwanted micron-sized dust. By minimizing environmental toll at the production stage, we help laboratories comply with their own waste mandates, cutting down on hazardous disposal costs and ensuring a cleaner working environment. For lab staff, high purity means less need for post-analysis cleanup. The product remains stable under ordinary storage but avoids the residual solvent odors or skin irritants that sometimes accompany hastily packaged indicator blends from less disciplined facilities.
A reliable indicator does more than help technical staff—its effect on research output can be dramatic. One graduate thesis, blocked by unresolved titration ambiguity, moved forward after the supervising professor switched to our batch. The PhD candidate later wrote to us, describing clear, repeatable endpoints that finally allowed for publishable results. Teachers in underfunded outreach programs report that their indicator budgets stretch further because a little of our product goes a long way: educators can perform a greater number of demonstrations without restocking, and students get a hands-on understanding of endpoint behavior without guesswork.
Industrial researchers see benefits in another direction: straightforward compound mapping in solvent selection protocols. The same confidence in pH transitions extends into specialty applications like colorimetric screening for buffer strength, soil pH mapping, and monitoring subtle shifts in process water chemistry across continuous manufacturing lines.
Some labs prepare stock solutions, others add indicator directly to their titration mix. Over time, we learned that fresh, direct-addition often produces sharpest endpoints, but our catecholsulfonphthalein remains stable when stored in buffer for weeks. Our technical notes include best-practice guidance informed by feedback from hundreds of real lab workers. Some users in metal analysis opt to adjust standard concentrations to extend working range; our consistently pure powder means the math behind these adjustments is simple, reducing ambiguity in multi-step protocols.
Many commercial indicators quietly blend in small percentages of inferior dye or “stretch” content with non-reactive bulk. The result is weaker color, confusing pH response, or batch variability. Our decades of in-house synthesis and QC allow us to avoid those pitfalls. If a sample does not meet our internal reference on absorbance or color breakpoint, we keep it off the market. We have no external shareholders demanding batch count over quality, so the pace of release fits the pace of real chemistry—not sales quotas. This discipline makes all the difference in getting repeatable, defensible results.
A common concern, especially from high-volume or compliance-driven operations, centers on documentation and batch consistency over multi-year contracts. We hold retention samples, and each has a corresponding data sheet matching the original batch analysis, providing peace of mind to labs with strict audit trails or regulatory filings.
Not all challenges come from inside the analytical workflow. Sometimes, globalization of laboratory supply chains means inconsistent deliveries, communication delays, or redundant repackaging. Our direct manufacturing setup eliminates those snags. Large buyers work with our plant chemists—from technical questions about solubility in unusual solvents to practical issues like improved packaging for humid climates. Our research team responds to pattern-based inquiries: for example, in regions with extra-strict import rules regarding certain chemical markers, we help tailor documentation and verification so labs have nothing to worry about come audit time.
This partnership works in the other direction too. Innovative customers share suggestions, and our team often pilots small-batch improvements based on real-world feedback. Over the years, user-driven tweaks—ranging from changes in neck size on glass bottles, to improvements in tamper-evident seals, to direct shipment in reusable containers for eco-conscious labs—have kept us grounded in the practicalities of daily laboratory work.
A public health lab encountered persistent endpoint ambiguity using off-the-shelf indicators. A switch to our high-purity catecholsulfonphthalein improved detection limits and eliminated staff re-training costs. A contract analytical laboratory working with rare earth metal quantification shortened its turnaround by switching, reporting more consistent titration curves in serum and mineral matrices. Even in teaching demos with mixed-age school groups, using our indicator improved learning outcomes, as more students could successfully reproduce key results without needing instructor intervention.
One forensics lab reached out after a run of unusual trace results suggested contamination in a standard buffer. Once they replaced their indicator—after analysis showed a contaminant traceable to a common repacking additive—the “mystery peaks” vanished. These are not one-off stories, but evidence of a persistent pattern: when analysts use pure, well-documented, and directly manufactured catecholsulfonphthalein, uncertainty drops and productivity rises.
Our company’s history is shaped by people with practical laboratory backgrounds. Chemists, not just business managers, guide our process improvements. Engineers, not just procurement staff, oversee equipment updates. As the field of analytical chemistry continues to evolve—embracing faster workflows, expanded digital tracking, and higher reliability—our commitment to consistent indicator quality remains unchanged. We remain actively involved in conversations about indicator design: from adding color-blind friendly visual references, to survey-based improvements in packaging, to support for longer-term storage requirements in remote field deployments.
Laboratory requirements continue to evolve. Demands for traceable, reliable, and cost-effective indicators have only grown more urgent, especially as environmental testing and pharmaceutical QC processes expand. By holding catecholsulfonphthalein to a higher bar for purity, transparency, and direct manufacturer support, we do more than provide a chemical; we help labs work with results that hold up to scrutiny, semester to semester, year on year. New applications in analytical chemistry push us to keep refining what we do, while old-fashioned attention to direct contact with users keeps innovation grounded in daily practical needs.
As competitive as the chemical supply sector may get, the stories we hear daily—labs running more smoothly, students learning with fewer mistakes, audits closing without red flags—remind us to focus on what works. Catecholsulfonphthalein, produced entirely in-house, remains our answer to indicator challenges old and new.
