入门
在 Duaer 里列出质量候选物
在 Duaer 里按观测 m/z 与加合离子列出 PubChem 候选化合物。一次成功查询用 1 额度。
能拿到什么
Duaer 数据市场里的「Mass candidates」一次成功查询 1 额度，查不到结果也算一次。
每个候选带 ppm 误差和 InChIKey；只凭质量不能定结构。
逐步处理未知特征见 用 Duaer 注释未知特征。
在画布里检索
- 打开节点创建器，选 Duaer 数据 → Mass candidates。
- 填 m/z。
- 选 Adduct（默认 [M+H]+），可选 Tolerance (ppm)，默认 5。
- Limit 默认 10，最大 20。执行。
成功扣 1 额度；输入为空或来源失败不扣。
用 API 调用
- GET https://api.duaer.com/v1/data/mass-candidates?...
- Authorization: Bearer <Duaer key>
下方是与「复制技能」相同的英文技能。
调用技能（英文）
与数据市场「复制技能」一致。
---
name: duaer-mass-candidates
description: >-
List PubChem compounds that fit an observed m/z and adduct through Duaer.
One successful search uses 1 Duaer credit.
---
# Duaer mass candidates
Turn an observed m/z into candidate compounds from PubChem through Duaer with a Duaer key.
## Call
`GET https://api.duaer.com/v1/data/mass-candidates?mz=181.0707&adduct=%5BM%2BH%5D%2B&ppm=5&limit=10`
Header: `Authorization: Bearer <Duaer key>`
Use an account key or a model API key.
Get a Duaer key: https://skills.duaer.com/keys.md
`mz` is required.
- `mz` — observed m/z of the feature.
- `adduct` — optional. `neutral`, `[M+H]+`, `[M+Na]+`, `[M+NH4]+`, `[M+K]+`, `[M+H-H2O]+`, `[M-H]-`, `[M+Cl]-`, or `[M+FA-H]-`. Default `[M+H]+`.
- `ppm` — optional. Mass tolerance in ppm, up to 100. Default 5.
- `limit` — optional. From 1 to 20. Default 10.
## Result
Each item has `source`, `title`, `url`, `summary`, `cid`, `formula`, `monoisotopicMass`, `neutralMass`, `ppmError`, `inchikey`, and `iupacName`.
Candidates come in PubChem relevance order. Check a candidate's reference spectra with https://skills.duaer.com/mona.md or https://skills.duaer.com/massbank.md (`inchikey`).
To work an unannotated feature step by step, follow https://skills.duaer.com/metabolic-dark-matter.md.
## Credits
One successful search uses 1 credit, including a search that finds no match.
Empty input, a failed source, or no remaining credits uses 0.
No remaining credits returns 402 and does not search.
A missing key returns 401.
常见问题
Duaer 的 Mass candidates 检索扣多少额度？
一次成功扣 1 额度，查不到结果也算一次；输入为空或来源失败不扣。
同组