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本文系统地研究了硫代苹果酸在络合滴定中的掩蔽性能，发现它在ｐＨ１．５～１０可作为Ｓｎ￣（４＋）、Ｓｂ￣（３＋）、Ｔｌ￣（３＋）、Ｂｉ￣（３＋）、Ｃｕ￣（２＋）、Ｈｇ￣（２＋）和Ａｇ￣＋等的掩蔽剂（在ｐＨ２～３．５还可掩蔽Ｆｅ￣（３＋））。掩蔽上述离子后，可在ｐＨ２．５～３用Ｔｈ￣（４＋）回滴ＥＤＴＡ，在ｐＨ５～６用ＥＤＴＡ滴定Ｚｎ￣（２＋）或Ｙｂ￣（３＋）等，或在ｐＨ１０用ＥＤＴＡ滴定Ｍｇ￣（２＋）、Ｃａ￣（２＋）、Ｍｇ￣（２＋）＋Ｃａ￣（２＋）和Ｍｎ￣（２＋）等。在ｐＨ５～６，硫代苹果酸能置换Ｃｕ￣（２＋）、Ｓｎ￣（４＋）、Ｂｉ￣（３＋）、Ｈｇ￣（２＋）或Ｔｌ￣（３＋）的ＥＤＴＡ络合物中的ＥＤＴＡ，而作这些金属离子的选择性置换滴定。已用硫代苹果酸为掩蔽剂，成功地测定了锡青铜中的锌、铅基合金中的铅、铋精矿和合成武德合金中的铋。
In this paper, we systematically studied the masking ability of thiomalate in complexometric titration and found that it can be used as a solute in the complexation titration at pH1.5 ~ 10, which can be used as Sn 4+, Sb 3+, Tl 3+, Bi 3+ ), Cu ~ (2 +), Hg ~ (2+) and Ag ~ + (masking Fe ~ (3+) at pH2 ~ 3.5). After the above ions are masked, EDTA can be titrated back with Th ~ (4+) at pH 2.5 ~ 3, Zn ~ (2+) or Yb ~ (3+) can be titrated with EDTA at pH 5-6 or titrated with EDTA at pH 10 ~ (2 +), Ca ~ (2 +), Mg ~ (2 +) + Ca ~ (2+) and Mn ~ (2+). At pH 5-6, thiomalate replaces EDTA in EDTA complexes of Cu 2+, Sn 4+, Bi 3+, Hg 2+, or T 3+ Selective exchange titration of these metal ions. Sulfur-containing malate has been used as a masking agent to successfully determine zinc in lead bronze, lead in lead-based alloys, bismuth concentrate, and bismuth in synthetic tungsten alloys.